Analysis of Alternatives Non-Confidential Version
ANALYSIS OF ALTERNATIVES
ANALYSIS OF ALTERNATIVES NON-CONFIDENTIAL VERSION
Legal name of applicant(s): Aloys F. Dornbracht GmbH & Co. KG
Submitted by: Aloys F. Dornbracht GmbH & Co. KG
Substance: Chromium trioxide, EC No: 215-607-8, CAS No: 1333-82-0
Use title: Functional chrome plating with decorative character for sanitary applications
Use number: 1
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ANALYSIS OF ALTERNATIVES
Disclaimer
This document shall not be construed as expressly or implicitly granting a license or any rights to use related to any content or information contained therein. In no event shall applicant be liable in this respect for any damage arising out or in connection with access, use of any content or information contained therein despite the lack of approval to do so.
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ANALYSIS OF ALTERNATIVES
CONTENTS
DECLARATION ...... XI 1 SUMMARY ...... 1 2 INTRODUCTION ...... 4 2.1 The substance ...... 4 2.2 Scope - uses of chromium trioxide ...... 4 2.3 The sanitary sector ...... 5 2.4 Purpose and benefits of chromium trioxide usage for coating of sanitary goods ...... 5 3 ANALYSIS OF SUBSTANCE FUNCTION...... 7 3.1 Metallic chrome coating in sanitary applications ...... 7 3.2 Process description for functional chrome plating with decorative character ...... 9 3.2.1 Plating process for sanitary products made from metal substrates ...... 10 3.2.1.1 Cr(VI)-free pre- and main-treatment processes ...... 11 3.2.1.2 Chrome-plating step ...... 12 3.2.1.3 Post-treatment processes ...... 12 3.3 Key functionalities of chromium trioxide based electroplating ...... 13 3.3.1 Corrosion resistance ...... 14 3.3.2 Wear resistance / abrasion resistance ...... 15 3.3.3 Adhesion ...... 15 3.3.4 Chemical resistance / resistance against cleaning agents ...... 16 3.3.5 Temperature change resistance / heat resistance ...... 16 3.3.6 Colour consistency ...... 16 3.3.7 Surface appearance ...... 17 3.3.8 Prevention of nickel leaching ...... 18 3.3.9 Sunlight resistance / UV resistance ...... 19 3.3.10 Process conditions and reliability ...... 19 3.3.11 Longevity ...... 19 3.4 European drinking water directive ...... 20 4 ANNUAL TONNAGE...... 22 5 IDENTIFICATION OF POSSIBLE ALTERNATIVES ...... 23 5.1 Description of efforts made to identify possible alternatives ...... 23 5.1.1 Research and development ...... 23 5.1.2 Data searches ...... 24 5.1.3 Consultations ...... 24 5.2 List of possible alternatives ...... 24 6 SUITABILITY AND AVAILABILITY OF POSSIBLE ALTERNATIVES ...... 26 6.1 Rejected Alternatives (No. 3 – 11) ...... 26 6.2 Shortlisted alternatives ...... 28 6.2.1 ALTERNATIVE 1: Trivalent chromium electroplating ...... 28 6.2.1.1 Substance ID and properties / process description ...... 28 6.2.1.2 Technical feasibility ...... 29 6.2.1.3 Economic feasibility ...... 34 6.2.1.4 Reduction of overall risk due to transition to the alternative ...... 36 6.2.1.5 Availability ...... 36 6.2.1.6 Conclusion on suitability and availability for trivalent chromium electroplating ...... 36 6.2.2 ALTERNATIVE 2 a: PVD based processes - PVD metal ...... 37 6.2.2.1 Substance ID and properties / process description ...... 37 6.2.2.2 Technical feasibility - PVD metal ...... 38 6.2.2.3 Economic feasibility ...... 42 6.2.2.4 Reduction of overall risk due to transition to the alternative ...... 42 6.2.2.5 Availability ...... 43 6.2.2.6 Conclusion on suitability and availability of PVD metal processes ...... 43 6.2.3 ALTERNATIVE 2 b: PVD based processes - lacquer + PVD + lacquer ...... 43 6.2.3.1 Substance ID and properties / process description ...... 43 6.2.3.2 Technical feasibility - lacquer + PVD systems ...... 44 6.2.3.3 Economic feasibility ...... 49
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6.2.3.4 Reduction of overall risk due to transition to the alternative ...... 50 6.2.3.5 Availability ...... 51 6.2.3.6 Conclusion on suitability and availability of lacquer + PVD systems...... 51 6.3 Outlook on substitution ...... 52 7 CONCLUSIONS ...... 54 7.1 Overall conclusion on suitability and availability of possible alternatives ...... 54 7.2 Information on the review period applied for ...... 55 7.3 Substitution effort taken by the applicant if an authorisation is granted ...... 56 8 REFERENCE LIST ...... 57 9 APPENDIX 1: INFORMATION ON RELEVANT SUBSTANCES FOR IDENTIFIED ALTERNATIVES ...... 58 10 APPENDIX 2: SOURCES OF INFORMATION ...... 63
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ANALYSIS OF ALTERNATIVES
List of Tables:
Table 1: Most promising alternatives with colour-coded technical assessment criteria with available information. 2 Table 2: The substance of this analysis of alternatives. 4 Table 3: Overview on subsequent coating treatment steps for sanitary products made from metal substrates. These steps do not comprise the use of chromium trioxide. 11 Table 4: Key functionalities of chromium trioxide based electroplating (the table is non-exhaustive but covers the most relevant functionalities for evaluation of potential alternatives and alternative coatings). 13 Table 5: List of plating alternatives categorised. 25 Table 6: Alternatives not applicable for sanitary applications with corresponding technical limitations. 26 Table 7: NSS-Test with Cr(III)-coated sanitary fittings made of brass. 30 Table 8: Kesternich-Test with Cr(III) coated sanitary tap parts made of brass. 31
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List of Figures
Figure 1: Functional chrome plated sanitary installations from the applicant’s portfolio. 8 Figure 2: Simplified overview of the process steps involved in functional chrome plating with chromium trioxide for metal substrates; the yellow colour indicates the process steps where chromium trioxide is involved. 9 Figure 3: Multi-layer system of metallic chrome coating. Scheme is not true to scale. 10 Figure 4: General flow chart for the plating process of brass, zinc die-cast and copper parts. 10 Figure 5: Testing strategy of key functionalities. 14 Figure 6: Technical drawing of a hand blender with colours indicating areas with different grades of prominence to the observer (red: most prominent area, yellow: less prominent area, green: area not visible to the observer under normal conditions of use). 17 Figure 7: 200 h salt spray test (EN ISO 9227) with Cr(VI) (left) and Cr(III) (right) coated brass parts. 30 Figure 8: Kesternich Test of brass coated with Ni/Cr(III) after 3rd cycle. 32 Figure 9: Salt spray test with PVD coated brass thermostat bodies. 39 Figure 10: Salt spray test with lacquer coated plastic substrates following EN ISO 9227. 45 Figure 11: Abrasion test with lacquer + PVD + lacquer coated sample after different cycles. 46 Figure 12: Abrasion test with lacquer + PVD + lacquer coated ABS sample (top) and Cr(VI) coated brass sample (bottom) after different numbers of cycles (1 = 50 cycles, 2 = 100 cycles, 3 = 200 cycles, 4 = 500 cycles, 5 = 1,000 cycles). 47 Figure 13: Review period applied for. 53
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ANALYSIS OF ALTERNATIVES
Abbreviations ABS Acrylonitrile-Butadiene-Styrene Acute Tox. Acute Toxicity AfA Application for Authorisation AoA Analysis of Alternatives ASTM American Society for Testing Materials Aquatic chronic Hazardous to the aquatic environment BAM Federal Institute for Materials Research BedGgstV German Commodity Ordinance (Bedarfsgegenständeverordnung) Carc. Carcinogenicity CASS Copper Accelerator Salt Spray Test Cr(0) Elementary Chromium Cr(III) Trivalent Chromium, Chromium (III) Cr(VI) Hexavalent Chromium, Chromium (VI)
CrO3 Chromium Trioxide CSR Chemical Safety Report CTAC Chromium Trioxide Authorisation Consortium CVD Chemical vapour deposition DIN German Organization for Standardization (German Industry Standards) DLC Diamond Like Carbon DVGW German Technical and Scientific Association for Gas and Water EN European Norm EU European Union Eye Dam. Serious eye damage Eye Irrit. Eye irritation Flam. Sol. Flammable solid FuSchiDec Working group Funktionale Schichten mit dekorativem Charakter GT0/GT1 Result classification in cross-cut test HV Vickers Hardness IBAD Ion Beam Assisted Deposition ISO International Organization for Standardization
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IUPAC International Union of Pure and Applied Chemistry LTAVD Low Temperature Arc Vapour Deposition NSST Neutral Salt Spray Test OEM Original Equipment Manufacturer PVD Physical Vapour Deposition REACH Registration, Evaluation, Authorisation and Restriction of Chemicals, Regulation 1907/2006, as amended R&D Research and Development Repr. Reproductive toxicity SEA Socio Economic Analysis Skin Sens. Skin sensitisation Skin irrit. Skin irritation SST Salt Spray Test STOT SE Specific target organ toxicity, single exposure SVHC Substance of Very High Concern TrinkwV German Drinking Water Ordinance (Deutsche Trinkwasser Verordnung) UBA German Environmental Protection Agency (Umweltbundesamt) UV Ultraviolet
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Glossary
Term Definition Parameter describes the tendency of dissimilar particles or surfaces to cling Adhesion to one another (for example adhesion of coating to substrate). Alternative Potential alternative provided to the sanitary sector for their evaluation. Typical method for surface treatment of parts. May also be referred to as Bath dipping or immersion. Parameter is defined as the ability of solid materials to resist damage by Chemical resistance chemical exposure. A coating is a covering that is applied to the surface of an object, usually Coating referred to as the substrate. The purpose of applying the coating may be functional, decorative, or both. Means applied to the metal surface, for example by electroplating, to prevent Corrosion protection or interrupt oxidation of the metal part leading to loss of material. The corrosion protection provides corrosion resistance to the surface. Electrical conductivity The measure of the ability of a material/coating to conduct electric current. Forming a metal coating on the part by an electrochemical method in an Electroplating electrolyte containing metal ions and the part is the cathode, an appropriate anode is used and an electrical current is applied. Process changing surface morphology of plastic substrate. This is a pre- Etching of plastics treatment step of the process chain preparing the surface before subsequent plating. The electrochemical treatment of metal, plastic or composite surfaces to deposit metallic chromium to achieve an improvement in the surface appearance, level of corrosion protection and to enhance durability. In functional plating with decorative character, chromium trioxide is used to Functional chrome plating deposit a coating of typically 0.1- 1.0 µm, or, where increased corrosion for sanitary applications resistance is required, a ‘micro cracked’ chromium deposit at thicknesses of typically 0.5 - 2.0 µm, over a nickel undercoat. Functional plating with decorative character may include use of chromium trioxide in a series of pre-treatments and surface deposits. After having passed qualification and certification, the third step is to Implementation implement or industrialize the qualified material or process in all relevant activities and operations of production, maintenance and the supply chain. Due to the nickel present in the coated product, a certain amount of nickel may leach out from the surface in contact with skin, drinking water or other Nickel leaching materials. This may cause allergic reactions and a legally implemented Ni threshold is present for consumer goods. The main treatment, chromium trioxide based electroplating, occurs after Main treatment the pre-treatment and before a post treatment (if applicable). Passivation Process providing corrosion protection to a substrate or a coating. Post-treatment processes are performed after the chromium trioxide main Post-treatment treatment. Their application is depending on the respective kind of chromium trioxide based electroplating. Pre-treatment processes are substrate specifically used to create caverns for Pre-treatment the subsequent main treatment (etching of plastics). The pre-treatment
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ANALYSIS OF ALTERNATIVES
Term Definition process must also provide chemically active surfaces for the subsequent treatment. A series of surface treatment process steps. The individual steps are not stand-alone processes. The processes work together as a system, and care Process chain should be taken not to assess without consideration of the other steps of the process. In assessing alternatives for chromium trioxide, the whole process chain has to be taken into account. Plating Electrolytic process that applies a coating of metal on a substrate. (OEM) validation and verification that all material, components, equipment Qualification or processes meet or exceed the specific performance requirements which are defined in the certification specifications. Reflective behaviour The ability of a coating to reflect light. Sunlight resistance / UV Resistance to photochemical degradation under the influence of sunlight, as resistance well as resistance to artificial light. Temperature change The ability of a coating to withstand temperature changes and high resistance / heat resistance temperatures. UV-lacquers are based on the same components as other wet lacquers, but UV lacquer include photo initiators as a special component. These photo initiators decompose in UV irradiation and promote the coherent lacquer layer. Wear resistance / abrasion The ability of a coating to resist the gradual wearing caused by abrasion and resistance friction.
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DECLARATION We, Aloys F. Dornbracht GmbH & Co. KG, request that the information blanked out in the “public version” of the Analysis of Alternatives and Socio-Economic Analysis report as well as the Chemical Safety Report is not disclosed. We hereby declare that, to the best of our knowledge as of today (31.10.2018) the information is not publicly available, and in accordance with the due measures of protection that we have implemented, a member of the public should not be able to obtain access to this information without our consent or that of the third party whose commercial interests are at stake.
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ANALYSIS OF ALTERNATIVES
1 SUMMARY The Analysis of Alternatives (AoA) forms part of the Application for Authorisation (AfA) for the continued use of chromium trioxide in electroplating of metal substrates for sanitary applications at Aloys F. Dornbracht GmbH & Co. KG at the production site in Iserlohn (Germany). In the sanitary sector, electroplating is used to achieve a high-quality surface with excellent durability in contact with aggressive and demanding environmental conditions and at the same time has a high aesthetic and decorative value. The finishes have a bright or matt silvery appearance. The metallic chrome layer is applied as final coating on top of a multi-layer system and the combination of underplates is responsible for the final appearance (bright or matt) of the top coating as well as for the even surface. The underplates vary depending on the different required functionalities of the final product and the used substrate. The applicant uses chromium trioxide for the coating of sanitary products manufactured from metal (brass, copper, zinc die-cast). The usage of chromium trioxide in electroplating for sanitary applications has multifunctional advantages, which are mainly based on the unique characteristics of the hexavalent chromium compound. These numerous beneficial properties of metallic chrome coatings created from chromium trioxide are critical for sanitary applications and have made this compound the state-of-the-art substance. The critical properties of the metallic chrome layer for sanitary applications are: • Corrosion resistance; • Wear resistance; • Adhesion; • Chemical resistance; • Temperature change / heat resistance; • Colour consistency; • Surface appearance; • Prevention of nickel leaching; • Longevity. Importantly, all above-mentioned key functionalities and related minimum requirements are highly interconnected with each other and therefore it is mandatory that a potential alternative sufficiently fulfils every single minimum requirement to achieve a high-quality surface under the conditions of use and subsequently to prove suitability of the alternative technology. Identification of possible alternatives In this AoA for the substitution of chromium trioxide in electroplating for sanitary applications, three most promising alternative technologies are described in detail (Chapter 6) for the main treatment. The applicant conducted a detailed technical and economic assessment for these alternatives but none of them provided with the required combination of technical performance at current stage. Therefore,
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ANALYSIS OF ALTERNATIVES a drop-in alternative for state-of-the-art functional chrome plating using chromium trioxide is not available. The most promising alternatives to Cr(VI)-based plating process are trivalent chromium electroplating (Cr(III) electroplating) and PVD-based processes. However, these two processes differ fundamentally. Trivalent chromium plating is a galvanic process similar to Cr(VI) electroplating. The PVD-based processes do not require chemical etching pre-treatment but use a completely different coating technology. Table 1: Most promising alternatives with colour-coded technical assessment criteria with available information. Alternative Technical key functionalities method Wear Temperatu Substrate Surface Corrosion resistance / Chemical re change / Colour Process Adhesion compati- appea- resistance abrasion resistance heat consistency conditions bility rance resistance resistance varying, varying, Trivalent chromium mostly mostly electroplating failed failed depending depending PVD based on on processes: PVD deposited deposited metal metal metal depending depending PVD based on depending on processes: Lacquer deposited on substrate deposited + PVD + lacquer metal metal Red = not sufficient; Yellow = parameters/assessment criteria fulfilment not yet clear; Green = sufficient; Colourless = no data; Intensive R&D on Cr(III) electroplating and PVD-based processes has been performed over many years. Although technical improvements of these potential alternatives have been achieved in recent years, especially on Cr(III)-based processes, they can still not be considered as technically feasible for sanitary applications as several key functionalities such as corrosion or colour consistency are not fulfilling the requirements. From the R&D carried out over the last years and the performance characteristics of Cr(III) electroplating, applied in a comparable galvanic process, this process is the most promising and favoured alternative for sanitary applications and therefore the main focus of current and future R&D efforts by the applicant; Again, despite major achievements, neither Cr(III) nor PVD can be considered as technically feasible and are not available to replace chromium trioxide as a commercial application at the current stage of development. Substitution timeline
The applicant is working toward a substitution and transition to Cr(VI)-free surface treatment of sanitary applications. However, this is a complex and lengthy process where several factors need to be taken into account. The applicant’s development and implementation process is separated in different phases presented in Figure 13 and described in more detail in Chapter 6.3. Review period Extensive evaluation of potential alternatives to electroplating for sanitary applications is carried out in the present AoA. Furthermore, economic aspects, as well as aspects of approval and release requirements in the sanitary sector, are assessed with regard to a future substitution of the substance. Due to the unique functionalities and performance of the chromium trioxide based electroplating, it is a challenging and complex task to replace this special process used for the surface treatment of sanitary applications. Until now, none of the technologies were able to compete with the performance
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ANALYSIS OF ALTERNATIVES of electroplating using chromium trioxide. For the derivation of the review period, the applicant wants to highlight the following key points:
• The benefits of continued use outweigh the risk by a considerable ratio of at least 1 : 1,657;
• Until now, no drop-in alternative is available on the market which fulfils all technical key requirements for sanitary applications and;
• The applicant has been engaged in identifying alternatives in form of industry wide exchange and projects over the last 10 years and has been collaborating with suppliers of alternatives for many years;
• If an alternative is found and approved, the phase out of Cr(VI) is a long process, given the fact that it is directly dependent on the acceptance by customers and electroplating is the applicant’s core business;
• The dominant market position of Cr(VI) plated sanitary products over a long time, together with the continued availability of Cr(VI) plated imports from non-EU if no authorisation is granted, suggests that any alternative must at least match the performance and price characteristics of Cr(VI) plated products to satisfy customer needs and to initiate penetration of the market. Consequently, return of investment can only be achieved if the implementation of a new technology is considered acceptable from a technical and economic perspective under these aspects. As a result of all these findings, a review period of at least 12 years was selected because it coincides with the best-case scenario estimated by the applicant for time required for a complete substitution of chromium(VI) plated sanitary goods.
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ANALYSIS OF ALTERNATIVES
2 INTRODUCTION
2.1 The substance The following substance is subject to this analysis of alternatives (Table 2).
Table 2: The substance of this analysis of alternatives.
Substance Intrinsic property(ies)1 Latest application date² Sunset date³
Chromium trioxide Carcinogenic 21 March 2016 21 September 2017 (category 1A) EC No: 215-607-8 Mutagenic CAS No: 1333-82-0 (category 1B) 1 Referred to in Article 57 of Regulation (EC) No. 1907/2006 ² Date referred to in Article 58(1) (c) (ii) of Regulation (EC) No. 1907/2006 3 Date referred to in Article 58(1) (c) (i) of Regulation (EC) No. 1907/2006
Chromium trioxide is categorized as substance of very high concern (SVHC) and is listed on Annex XIV of Regulation (EC) No 1907/2006. Chromium trioxide is an inorganic salt based on hexavalent chromium (Cr(VI)). Adverse effects are evaluated in detail in the chemical safety report (CSR). Chromium trioxide is categorised as a non-threshold substance and therefore the socio-economic analysis (SEA) route is foreseen under REACH. The applicant applies for authorisation to continue the use of chromium trioxide for electroplating of sanitary installations manufactured from different substrates (see section 2.2). The aim of this AoA is to demonstrate that no feasible alternatives to chromium trioxide will be available before 2030 and thus a review period of 12 years is applied for.
2.2 Scope - uses of chromium trioxide The applicant performs functional chrome plating of sanitary installations in 1 facility in Iserlohn (Germany). Chromium trioxide is used for electroplating of sanitary goods such as fittings/taps, shower heads, valves and piping for bathroom and kitchen applications made of different substrates. More precisely chromium trioxide is used in the following way: Brass, Copper, Zinc die-cast: - Electroplating: applying a metallic chrome coating on top of specific underplates and on different types of substrates, creating either a bright (shiny) or matte chrome coating. It is important to mention that the applicant is covered under CTAC for the same use described in this application, with a recommended review period of 4 years.
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2.3 The sanitary sector The applicant is operating its business in the German sanitary industry. Characteristics of the German sanitary industry comprise a high product quality as well as environmentally responsible and socially sustainable working conditions (VDS, 2017). About 506,000 employees in this industry sector generated a total turnover of EUR 24.5 billion in 2017. Since 2009, sales revenues increased by 28 %, whereas an increase of over 26 % in Germany was offset by an increase of 37 % abroad. Both for German and other European sanitary producers, innovation is a crucial factor for being able to persist in a highly competitive market with non-EEA companies, especially from Asia. The most important trends for innovation in the sanitary sector and especially for bathrooms presented on the ISH 2017 are health, comfort, individualisation, digitalisation and environmental consciousness. Dornbracht is positioned at the highest end of the market considering product quality and prices. As a luxury brand, the market is limited to a smaller group of very demanding customers. In order to succeed in this highly demanding sector, Dornbracht fulfils very specific and individual requests and in some cases even produces unique pieces, which might not always be economically viable in the short term but serves to promote customer loyalty. Such a commitment can be considered a unique selling point. This can be achieved since Dornbracht places the highest demands on design, materials and surfaces of its fittings. And once the product has left the manufacturing site, the company ensures the quality of assembly by the specialist trade through intensive training and years of cooperation.
2.4 Purpose and benefits of chromium trioxide usage for coating of sanitary goods The applicant produces different articles for sanitary installations which are coated with a functional chrome layer. The production takes place in 1 site in Iserlohn (Germany). The company offers a range of different products for sanitary applications, e.g.: • Washbasin fittings, showers and shower fittings; • Bath fittings and accessories for bathrooms and wellness areas; • Kitchen fittings. Functional chrome plating has been a well-proven and traditional coating for sanitary applications for more than 50 years to achieve the critical performance characteristics related to goods in contact with drinking water. Herein, the use of chromium trioxide has multifunctional advantages, mainly based on the characteristics of the hexavalent chromium compound. The following desirable properties of coatings produced from chromium trioxide have made this compound indispensable and a state of the art in the sanitary sector: • Excellent corrosion protection and chemical resistance to the substrates in a wide range of environments and conditions (bathrooms and kitchens in private households and public and corporate buildings, pools/spas); • Wear and abrasion properties; • A high aesthetic surface with mirror-like reflection; and • Longevity.
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ANALYSIS OF ALTERNATIVES
Due to these properties the functional chrome plated products are of high durability and a long service life. Although chromium trioxide is used for functional chrome plating of sanitary applications, no chromium trioxide residues are present on the chrome plated article and therefore no hazard arises from the finished product. The final surface meets the important regulatory requirements for contact with drinking water. Another great benefit of functional chrome plating with chromium trioxide is process reliability, which is necessary for the manufacture of products with constant quality. In this context it is of note that the applicant is positioned at the highest end of the market considering product quality and prices. As a premium brand, the market is limited to a smaller group of very demanding customers.
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3 ANALYSIS OF SUBSTANCE FUNCTION
3.1 Metallic chrome coating in sanitary applications In general, surface treatment of metals and plastic substrates is a very common and widely used procedure in many different industry sectors to increase the performance or in the first place enable the usage of these substrates in demanding applications. For the application of high performance surfaces in demanding environments, the use of chromium trioxide for the production of metallic chrome coated components has proven its perfect suitability to ensure high quality and performance of the final product over decades. Functional chrome plating is an essential process to influence the properties of a substrate in a way that the finished product performs optimal under the conditions of use.
For sanitary applications, functional chrome plating is used to achieve a surface with a high durability in contact with aggressive and demanding environmental conditions and at the same time has a high aesthetic and decorative value. The finishes have a bright or matt silvery appearance. The metallic chrome layer is applied as final coating on top of a multi-layer system and the combination of underplates is responsible for the final appearance (bright or matt) of the top coating as well as for the even surface. The underplates vary depending on the different required functionalities of the final product and the used substrate. The applicant uses chromium trioxide for the coating of sanitary products manufactured from metal (brass, copper, zinc die-cast). - Brass: E.g. washbasin fittings, shower fittings, kitchen fittings (ca. 80% of all parts); - Copper: Minor importance (< 1% of all parts); - Zinc die-cast: E.g. levers, covers, rosettes (ca. 15% of all parts). In the subsequent dossier, the term “metal substrates” is used, and with no further specification, all of the above-mentioned types of substrates are comprised within this term. If there are technical constraints or limitations to a specific kind of substrate, this is indicated in the respective paragraphs. Products for which a functional chrome layer is applied to are provided in Figure 1 below.
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Figure 1: Functional chrome plated sanitary installations from the applicant’s portfolio.
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3.2 Process description for functional chrome plating with decorative character Surface treatment is essential for influencing the properties of a substrate in a way that the finished product performs adequately under the conditions of use, ideally over a long lifetime. Applying a coating of functional chrome with decorative character is a process chain and can be divided in three sub-processes: the pre-treatment, the main process and the post treatment (see Figure 2). First, the surface of the substrate is pre-treated to remove impurities and activate the surface. A functional multi-layer system of metal layers is then applied by electroplating, with a final metallic chrome coating using chromium trioxide electroplating that is created on the product’s surface. The process chain is concluded by adequate post-treatments, for example rinsing and drying of the plated product.
• removal of impurities / • rinsing pre- main functional post- contaminations • drying treatment process chrome plating treatment • surface • inspection activation
Metal substrates
Figure 2: Simplified overview of the process steps involved in functional chrome plating with chromium trioxide for metal substrates; the yellow colour indicates the process steps where chromium trioxide is involved. The treatments are conducted in subsequent plating baths. All process steps are performed by dipping the substrates in a bath containing the process step specific aqueous solution. It is a wet-in-wet process, typically without intermediate storage of products at any time of the process chain, except for the final drying step. Numerous rinsing steps are performed along the process chain to prevent the carry-over of substances from one bath into another, which would otherwise lead to interference with the subsequent process step. The metallic chrome layer is applied as final coating on top of a multi-layer system (Figure 3). The combination of intermediate layers is responsible for the brightness of the top coating and the corrosion properties.
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Figure 3: Multi-layer system of metallic chrome coating. Scheme is not true to scale.
3.2.1 Plating process for sanitary products made from metal substrates Functional chrome plating of sanitary products from metal substrates takes place in the applicant’s production facility in Iserlohn (Germany). The production involves the following steps:
Figure 4: General flow chart for the plating process of brass, zinc die-cast and copper parts.
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ANALYSIS OF ALTERNATIVES
3.2.1.1 Cr(VI)-free pre- and main-treatment processes Several Cr(VI)-free pre- and main-treatment steps prepare the surface of the substrates for the functional chrome plating. Adequate preparation of the base substrate is a prerequisite of the process: adhesion between coating and substrate depends on the force of attraction at molecular level. Therefore, the surface of the substrate must be absolutely free of contaminants, corrosive products and other impurities until the coating process is finished. The pre-treatment steps for metal substrates are generally free of chromium trioxide. Table 3: Overview on subsequent coating treatment steps for sanitary products made from metal substrates. These steps do not comprise the use of chromium trioxide. Process step Purpose
Degreasing Removal of grease from the surface of the substrate (e.g. degreasing with ultrasonic bath or electrical degreasing).
Activation In an acidic medium, protective oxides formed on the surface of the substrates are removed in order to enable the adhesion of the following layers.
Copper Depending on the substrate, a copper layer can be applied on the substrate prior to the nickel deposition. This is optional for plating on brass substrates. The copper layer is used as an underplate to improve adhesion between the substrate and the first layer applied during the multi- layer plating process. This is to cover imperfections such as pits and scratches, and to create a shinier surface as a basis for the subsequent layers. The brilliant appearance of the copper layer is responsible for a bright appearance of the final coating.
Nickel step The application of nickel layers prior to the final metallic chrome layer is necessary, as only the multi-layer combination is able to meet the required key functionality of the final product. These are corrosion and chemical resistance, hardness, adhesion and surface appearance of the final product. The nickel layer as such characterizes the final appearance of the product as matt, satin or bright and is also applied in a two-layer system. It combines either semi-bright nickel layer and bright nickel layer or functional nickel layer or velour nickel layer. The two-layer nickel system outperforms the single nickel layers of the same thickness.
Rinsing A rinsing step is carried out in order to prevent the transfer of substances from one plating bath to another by dipping the parts in a bath containing clean rinsing water.
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3.2.1.2 Chrome-plating step An activation step after nickel deposition and prior to chromium plating may be necessary in case the nickel-plated parts are stored and a passive layer has been formed. The nickel surface must be activated by using a low concentrated chromium trioxide electrolyte and a very low current density prior to the actual chromium plating step. The metallic chrome layer is applied by electroplating based on the principle of electrolysis. Electroplating forms a coherent metal coating on the substrate with previously applied intermediate layers. It uses the substrate as a cathode and an inert anode (most often used are lead or tin) and induces an electrical current. The substrate is immersed in the electrolytic plating solution containing dissolved chromium trioxide and additives (electrolytes). During the electroplating process, the hexavalent chrome (Cr(VI)) is reduced to metallic chrome Cr(0) and builds up the metallic chrome coating (electrodeposition).
In this process, the concentration of CrO3 is between xxxxxxxxxxxxx. Additives such as sulphuric acid are typically added in concentrations of xxxxxxx. The bath temperature is typically in the range between xxxxxxxxx with an average current density between xxxxxxxxxxxxx. The thickness of the metallic chrome layer is typically in the range between 0.1 µm and 1.0 µm and depends on the geometry of the substrate. The bright chrome appearance of the product is not solely a result of the metallic chrome layer but also of the respective underplates. In contrast, the slightly bluish character of the metallic chrome coating is solely a result of applying a metallic chrome layer by chromium trioxide based electroplating. During the chrome electroplating process chain, numerous rinsing steps are carried out to prevent the drag-out of substances from one plating bath to the next. Rinsing is commonly performed by dipping the product in a bath filled with clean rinsing water. It usually occurs in several steps following the cascade technology. The most common technique is counter-current cascade rinsing, where the part is rinsed in a succession of rinsing baths that are dedicated to the plating bath. Most of the process water is handled in a closed-loop system minimizing wastewater streams by reusing rinsing water in another process bath of the same type. Refilling of the chromium trioxide electrolyte is always performed to the same bath. Overall, the electrolytic process of plating with chromium trioxide is performed at low temperatures (no high energy costs for heating of the bath). The coating is applied quickly and due to the bath application technique, almost all kind of articles with all different geometries (flat, complex, with inner cavities, etc.) and size (independently if small or big) can be plated.
3.2.1.3 Post-treatment processes Post-treatments comprise rinsing and cleaning steps to remove excess process chemicals from the product after the actual plating process is finished. After removal of the residues the product is dried and finally the surface quality inspected manually by trained personnel.
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3.3 Key functionalities of chromium trioxide based electroplating The unique functionalities of chromium trioxide make it an ideal substance for refining metallic surfaces. Functional chrome coatings provide a unique combination of surface properties, which is why it is not easy to find alternatives. The key functionalities defined here are used for the assessment of alternatives in Chapter 6. To give an overview on the widespread range of requirements, Table 4 lists the key functionalities for chromium trioxide plated surfaces for sanitary applications. More detailed information on the specific requirements is described in the chapters below. This list is intended to provide an evaluation basis for potential alternatives and alternative coatings. Table 4: Key functionalities of chromium trioxide based electroplating (the table is non-exhaustive but covers the most relevant functionalities for evaluation of potential alternatives and alternative coatings).
Key Functionality Technical requirements Corrosion resistance - 200 h NSS (EN ISO 9227, EN 248) - 4 to 24 h CASS EN ISO 9227 - 3 cycles in Kesternich Test EN ISO 6988 / DIN 50018 After finishing of a test, the piece is checked visually (without magnifying glass) against EN248. Wear resistance / abrasion resistance (scratch Taber abrasion test: no visually detectable damages after resistance) testing for up to 10,000 cycles with felt and weight Adhesion Cross-cut test EN ISO 2409 (GT0 to GT1) (after temperature cycle test) Chemical resistance (resistance against cleaning No visual degradation of the coating after testing with agents) different chemicals (company specific tests) Substrate compatibility Coating of different types of substrates shall be possible Temperature change resistance / heat resistance - 5 cycles in temperature cycle test according to DIN 53100 After finishing of the test, the pieces should be without any cracks, peeling, blisters etc. checked visually (without magnifying glass)
Colour consistency Colour shade, colour fastness; constant colour ΔE in the range of 0.0 – 0.5 across plating shops, plating lines and plating batches Surface appearance For easily visible surfaces no defects are tolerated Ni leaching Drinking water directive: long-term Nickel release test (26 weeks, EN 16058), < 20 µg/L in drinking water TrinkwV and 0.5 µg/cm² per week skin contact (BedGgstV, REACH Anhang XVII)
Sunlight resistance (UV exposure) Company specific sun tests Process conditions and reliability Potential alternative coating technologies must not exceed specific thresholds, e.g. related to temperature or processing times). In addition, products with constant high quality are required.
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Key Functionality Technical requirements Longevity 5 years warranty compulsory under construction law (Germany), long term tests necessary. In field tests products are installed and checked by laboratories after 6 and 12 months. The tests are continued until product failure. In general, the order of testing the relevant key functionalities is based on their criticality for sanitary applications. As most important functionality, the corrosion resistance is tested first. The typical testing approach includes a Kesternich and Salt spray test (corrosion resistance), a Taber abrasion test (wear resistance / abrasion resistance) followed by a Cross-cut test (adhesion). Subsequently, the chemical resistance is tested provided that the results of the previous tests are satisfactory. If testing results are considered not sufficient, no further tests are conducted for the remaining key functionalities (i.e. temperature change resistance / heat resistance, colour consistency, surface appearance, prevention of nickel leaching and sunlight resistance) but limitations related to the most critical key functionalities are identified and improvements are discussed and implemented (Figure 5).
Figure 5: Testing strategy of key functionalities. A more detailed description of the key functionalities taking different substrates into account is given in the following paragraphs.
3.3.1 Corrosion resistance Corrosion describes the process of oxidation of a metallic material due to chemical reactions with its surroundings, especially under the effect of humidity and oxygen. In this context, the parameter corrosion resistance means the ability of a metal to withstand gradual destruction by chemical reaction with its environment. It is crucial for longevity and safety of the products as corrosion may lead to release of nickel from the installations to drinking water and the exposure of the user’s skin to nickel as an allergen substance. Also, the aesthetic value of the installations for bathroom, kitchen and spa applications is dependent on adequate corrosion resistance over a long product life time.
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Corrosion resistance is tested by the applicant by using different test methods in accordance to customer standards. The main tests regarding corrosion resistance are salt spray tests according to EN ISO 9227. EN 248 describes the tests to be performed for electrodeposited nickel chrome coatings, however the tests for corrosion resistance refer to EN ISO 9227. The coated parts should not show defects exceeding a dimension of 0.3 mm to fulfil the requirements. In further tests, coatings are exposed to acidic rain atmosphere (sulphur dioxide) followed by a three cycle (72 h) Kesternich test according to EN ISO 6988 / DIN 50018. During this test, no defects should occur. When using a Neutral Salt Spray Test (NSST) according to EN ISO 9227 or the sanitary specific EN 248, the most common minimum corrosion requirement for the applicant is 200 h, but also higher corrosion resistance of > 500 h up to 1000 h NSST were stated to be required depending on the final application (e.g. private houses vs. hotels). Corrosion requirements under the more demanding CASS (Copper Accelerated Salt Spray) test range between 4 and 24 h. When using the Kesternich test method, the coatings have to withstand 3 cycles (8 h exposure / 16 h drying time).
3.3.2 Wear resistance / abrasion resistance The abrasion / wear resistance of a coating is its ability to resist the gradual wearing caused by abrasion and friction. The wear resistance of a coating is tested via its abrasive behaviour. A commonly used test method is the taber linear abrasion test. During this test, a rubbing material (i.e. felt strip) is rubbed over the coated surface with a defined force and number of cycles/repetitions. Whereas the distinct test procedure is company specific, the requirement is always the same: the coating shall not show any visually detectable damages after taber linear abrasion (“no scratches”).
3.3.3 Adhesion The parameter adhesion describes the tendency of dissimilar particles or surfaces to adhere to one another. The delamination of the different layers or the substrate is the result of poor adhesion. Sanitary goods are exposed to a large variety of chemicals and reagents and mechanical stress through intensive use. For the required life time and aesthetic appearance of all coated parts, it is important that the coatings applied to the substrates can withstand these effects. The most commonly used test method of the adhesive properties is a cross-cut test according to EN ISO 2409. For this test, a grid of six parallel and six perpendicular cuts are severing the overall coating down to the substrate. Afterwards, an adhesive tape is applied to the coating and then removed. The visual inspection after removal of the tape shall not show any detectable defects on the cuts equivalent to a cross-cut index GT0 (best index of a six-level scale). Further tests of the adhesive properties are performed after exposing the coating, or rather the cross- cut coating, to a temperature cycle test (“shock test”, “temperature change test”). This commonly used test is based on ASTM B571-97. A large variety of company specific and sector specific test conditions for the performance of temperature cycle and climate cycle tests are known, as the test is specified according to the field of application, type of coating, thickness of the coating, ductility and the composition of the substrate.
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Test conditions vary in terms of maximum temperature (for example 70 °C, 80 °C, or 140 °C), minimum temperature (for example minus 40 °C, minus 26 °C, plus 20 °C) and the time the coating is exposed to the respective minimum or maximum temperature (single exposure time, for example 120 seconds, 30 minutes, 4 hours, 24 hours). The number of cycles relates to the single exposure time. Under short exposure times, a high number of total cycles is performed (for example 300 cycles). In case of long single exposure times, a small number of cycles (for example 3 cycles, 5 cycles) is performed. The visual inspection of a cross-cut coating (according to EN ISO 2409) after exposing to a temperature cycle test has to fulfil the cross-cut index GT1.
3.3.4 Chemical resistance / resistance against cleaning agents The chemical resistance or resistance against cleaning agents is defined as the ability of solid materials to resist damage by chemical reactivity. In general, a coating that is not adequately resistant against cleaning agents shows corrosion. A number of different tests on resistance against cleaning agents are performed for sanitary applications. Different cleaning agents (such as vinegar extract with a concentration of 5% or other commercially available products) and personal care chemicals (such as toothpaste, nail polish remover, shampoo, soap) with varying concentrations are used for the tests. The cleaning agents are predominantly based on different organic acids and compounds, such as formic acid, sulfamic acid or lactic acid or glutaraldehyde. The tests are conducted under company specific conditions. They are based on similar test criteria and include evaluation of the chemical resistance in a spray test as well as in a continuous immersion test. After the spray test and continuous immersion test, no visual degradation of the coating should be detectable.
3.3.5 Temperature change resistance / heat resistance The base material (such as brass, zinc die-cast) and intermediate layers (such as copper layer, nickel layer) are characterized by individual thermal behaviour and they might differ in thermal coefficient of expansions and heat conductivity. Therefore, the coated product is tested for its thermal change and heat resistance, as different thermal behaviours of coating and substrate may result in surface blistering. Temperature change resistance is tested in a temperature cycle test in combination with a cross cut test according to DIN 53100. The test method specifies heating of the plated products for 30 minutes to a temperature of 60 °C, followed by a 30 minutes cooling period at room temperature. The parts are cooled down to -18 °C for 4 hours and subsequently brought back to ambient temperature. This cycle is repeated 5 times. The surface should not show any cracks, blistering or loosening of the coating.
3.3.6 Colour consistency For sanitary goods, it is critical that the coating process in use ensures the serial production of all parts with the same shade of colour, regardless of the plating shop, plating line or plating batch. The variation of the typical silvery-bluish colour of the metallic chrome coating, expressed as ΔE, is determined by a colour measuring device and deposited references. ΔE must be in the range of 0.0 –
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0.5, which are almost imperceptible colour differences. This is a decisive quality standard for the products the applicant manufactures and determines the actual value of the products for the customers. The colour is moreover a very obvious property of the products. Consistency of the colour shade is therefore a selling point and quality feature with regards to wholesale customers and plumbing companies, for whom such criteria are arguments why or why not to stick to a manufacturer. Indeed, also an alternative process must deliver a constant high-quality output regarding colour consistency.
3.3.7 Surface appearance The coating is inspected for visible and palpable surface defects, based on the applicant’s standards providing its customers with the best quality possible. The product surface is classified according to the tolerance of defects. Defects can appear in areas where they are easily/highly visible for the consumer, for example defects in surfaces areas out of sight (for example underneath a spot) are more likely to be accepted then on the top of a hand blender (see Figure 6).
Figure 6: Technical drawing of a hand blender with colours indicating areas with different grades of prominence to the observer (red: most prominent area, yellow: less prominent area, green: area not visible to the observer under normal conditions of use). The surface defects are typically differentiated according to the type of defect, its position, its size and the spacing of the defect. In general, highly visible areas must be free of any kind of defects such as pores, cracks and blistering, as the aesthetic appearance highly influences consumer decisions. The most common aesthetic screening test is the visual inspection performed according to company specific internal standards that require a perfect appearance of the plated surface. For this purpose, a reference sample is typically used for comparison. The number of the tolerable defects depends on the geometry of the defects (point shaped, linear or flat) and the location of the defect. For easily visible surfaces no defects are tolerated when the defect can be recognized with the eye under good illumination (products are sorted out), xxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx.
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3.3.8 Prevention of nickel leaching The multi-layer system of functional chrome includes at least one nickel layer. These nickel layers are of great importance and guarantee quality and appearance of the final coating. Due to the nickel present in the coated product, a certain amount of nickel may leach out from the surface in contact with skin, drinking water or other materials. This parameter is relevant where the coated product comes in contact with skin, food or other materials potentially affecting the health of the consumer. Therefore, the maximum nickel leaching rate of nickel plated products is regulated by law. The leaching occurs over a long period of time, depending on the corrodibility of the substrate’s surface. The nickel release rate depends on the type of coating and the coating process. Products which are designed to deliver drinking water are subject to national and international regulation (for example European Drinking Water Directive, German Drinking Water Ordinance TrinkwV) due to the water’s fundamental impact on public health. Parts plated in chromium trioxide plating lines have proven their quality in various leaching tests (for example NSF61; EN 16058). Alternatives must be comparable or better regarding their health impact – this point is important even for non-metallic coatings which may have contact with drinking water. For sanitary applications, the main use for metal parts and coated metal parts in the water supply are domestic service installations such as taps and sinks. Contact between metal and drinking water can lead to the release of metal ions into the water if the metal or metal layers (substrate) are corroded. Long-term nickel release to drinking water from substrates with a Ni coating or Ni intermediate layer can be determined with the long-term nickel release test (EN 16058). According to the REACH regulation, Annex XVII (Restrictions of the manufacturer, placing on the market and use of certain dangerous substances, preparation and articles), nickel shall (amongst others) not be used in articles intended to come into direct and prolonged contact with the skin if the rate of nickel release from the parts of these articles coming into direct and prolonged contact with the skin is greater than 0.5 μg/cm² per week and in articles where these have a non-nickel coating unless such coating is sufficient to ensure that the rate of nickel release from those parts of such articles coming into direct and prolonged contact with the skin will not exceed 0.5 μg/cm² per week for a period of at least two years of normal use of the article. In addition, these types of articles shall not be placed on the market unless they conform to the respective nickel release limit. In Germany, for example, sanitary parts used in direct contact with drinking water must meet the requirements of the German Drinking Water Directive and of the Environmental Protective Agency (for details please see Chapter 3.4). These require that the nickel concentration in drinking water caused by Ni migration should not exceed 20 µg/l. In addition, according to § 6 No 3 and Annex 5 of the German Consumer Goods Ordinance (applicable to all industry sectors), it is not permitted to place consumer goods with Ni and Ni containing compounds on the market, if more than 0.5 µg/cm² Ni per week is released. This applies to consumer goods that come into direct and prolonged contact with the skin. For consumer goods with a Ni free topcoat (such as a metallic chrome coating), the maximum Ni leaching for a time period of 2 years in normal use conditions shall also not exceed 0.5 µg/cm². Therefore, a nickel release test
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ANALYSIS OF ALTERNATIVES is performed according to the specifications of EN 1811. No Ni allergic reactions are allowed to occur after contact with the coated parts.
3.3.9 Sunlight resistance / UV resistance Sunlight resistance of a coating is defined by the ability to withstand degradation when exposed to sunlight or ultraviolet light. Long term sunlight exposure can cause UV degradation resulting in cracks and blistering of the coating. There are several company specific UV tests available, for example a four-week outdoor weathering of the coated products that needs to be passed without showing visual changes or damages. Further specifications for laboratory sun tests comprise exposure of the coating to 650 Watt for 588 h. This test should be passed without showing defects.
3.3.10 Process conditions and reliability Process conditions combine critical process properties such as temperature and coating time. Potential alternative coating technologies must not exceed a certain temperature threshold given by the substrate. In addition, process time is mostly important as an economic factor. Electroplating using chromium trioxide offers the possibility to treat large numbers of parts in a short period of time. Therefore, potential alternative technologies, even if the coating itself shows promising results, must have acceptable processing times to be practical on an industrial scale. Process reliability is crucial as products with a constant high quality over the period of use are requested by clients. Using immature technologies implies the risk of product failure which may be associated with high costs due to recalls. Additionally, it is of great importance that the source materials used in the alternative method are constantly available to guarantee product supply.
3.3.11 Longevity A unique property of functional chrome plating with chromium trioxide is that for the treated sanitary parts, a high longevity can be guaranteed. For installations as produced by the applicant, a long lifetime is in any case a desirable characteristic. Bathroom and kitchen installations are commodities for which the end customer generally can expect a long lifetime under the normal circumstances of use. The circumstances of use can differ from private households to public buildings and places of high frequentation like spas and hotels. For parts that fall under construction law, 5 years of warranty are compulsory (Germany). In this regard, the applicant’s quality standards must certainly also be ensured with (an) alternative(s). The measurement of the longevity of a sanitary product is basically included in all of the above mentioned key functionalities. Corrosion resistance, chemical resistance, nickel leaching, adhesion, UV resistance, temperature resistance, colour consistence and surface appearance are all aspects of longevity and are measured in the way they are in order to ensure that a high-quality product leaves the production to be sold to the customers.
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3.4 European drinking water directive Directive 98/83/EC (“on the quality of water intended for human consumption”) regulates the quality of water for human consumption. It aims to protect human health by ensuring the water quality designated for human consumption. Directive 98/83/EC has been transposed into the legislation of each EU Member State. In Germany, it was implemented in national law as German Drinking Water Directive (TrinkwV – Verordnung über die Qualität von Wasser für den menschlichen Gebrauch (Trinkwasserverordnung), 2001), which has been updated in January 2018. It regulates the microbiological and chemical quality of drinking water by giving threshold values for the respective indicator parameters. Regarding the overall requirements and the values for the indicator parameters, both the European Directive and the German Drinking Water Directive refer to the same basis and threshold values.
The directive also regulates the use of materials that are designed to come into contact with drinking water. Such substrates and materials used for the construction of new installations and for the maintenance of existing installations that are in contact with drinking water, are not allowed to negatively affect
- human health, - the smell and taste of drinking water, - nor to release substances (chemical indicator parameters) into drinking water in higher concentrations than would be avoidable by using current techniques. The German Environmental Agency (Umweltbundesamt - UBA) has introduced test regulations including parameters and test criteria to evaluate the hygienic suitability of the substrates and materials. The UBA maintains a “positive list” (Trinkwasserhygienisch geeignete metallene Werkstoffe) of substrates and materials which meet these requirements and are therefore allowed to be used in contact with drinking water. Any new material or coating that is intended to come in contact with drinking water must pass extensive tests to gain a certification and to be included in the positive list. The following German Industry Standards (DIN – Deutsche Industrie Norm) are in place for the testing of metallic materials that are in contact with drinking water: - DIN 50930-10 (Corrosion of metals) provides information on the necessary evaluation process that is further specified in EN 15664-1 (metal release test, design and operation) and EN 15664-2 (metal release test, test waters). - The long-term behaviour of metallic coated products in contact with drinking water is tested according to EN 16058 (influence of metallic materials on water intended for human) and the flexible coated parts are tested based on a regulation of the German association for gas and water (DVGW, work sheet W 543). The long-term material testing takes at least 26 weeks per test trial and product.
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For the long term testing according to EN 16058, UBA together with DVGW and manufacturer of sanitary parts discussed and developed testing criteria. However, as recently stated by UBA1, the long-term testing can currently not be considered for certification of products, as the obtained values are not reproducible and it was not possible to prove that similar products can be grouped together for testing. Consequently, every single product would need to be tested on its own, which is not feasible due to the sheer number of parts available and the duration of the testing taking 26 weeks.
During the last 10 years, it has not been possible for the working group of leading sanitary fitting manufacturers (including Dornbracht) and authorities to develop a shorter test method leading to comparable results compared to the standardised long-term test. It is also not foreseeable that such a procedure will be developed and used in the near future. This can be explained by the fact that mechanisms of action are not yet understood completely and that small changes in the surface treatment can lead to strong deviations. The responsibility related to compliance with limit values for metals lies with companies.
Accordingly, UBA cannot give any recommendation on how testing on nickel leaching needs to be carried out. It lies in the responsibility of the manufactures to ensure that their products are in compliance with the nickel leaching values as set out in the Drinking Water Directive.
The requirement for a testing of a coating is the listing of a substrate in the UBA “Positiv liste”. The testing of 30 raw materials of the “Positiv liste” took around 20 years and the testing of the applicant´s products for nickel migration would take considerable efforts over years without consideration of new series. An evaluation basis for the drinking water hygienic suitability for new coatings and materials as for example for sanitary parts with alternative coatings would need to be developed by UBA. Also, until today an evaluation basis for nickel does not exist.
Together with the above described material testing procedure, it is expected that huge year-long efforts are needed from the decision making for an alternative, until approval for the use in contact with drinking water can be achieved. The testing procedures need to comply with all regulations, to meet the required properties and finally - even more importantly - to guarantee the safety of drinking water.
1 https://www.umweltbundesamt.de/sites/default/files/medien/374/dokumente/180620_information_zu_nickelhaltigen_ueberzuegen_uba_0.pdf
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4 ANNUAL TONNAGE The annual tonnage band for the use of chromium trioxide in functional chrome plating with decorative character is xxxxxxxxxxxxxxx. The non-confidential annual tonnage band for the use of chromium trioxide in functional chrome plating with decorative character is 1 – 10 tonnes per year.
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5 IDENTIFICATION OF POSSIBLE ALTERNATIVES
5.1 Description of efforts made to identify possible alternatives
5.1.1 Research and development Much effort on alternatives for electroplating with chromium trioxide has been made and is still ongoing. The unique functionalities of Cr(VI) (explained in detail in section 3.3) make it an ideal and not easy to replace substance for sanitary applications where superior requirements such as surface appearance/colour consistency, corrosion and chemical resistance or abrasion resistance under demanding conditions have to be fulfilled. It is very challenging to find an approach which provides the essential combination of all key requirements as outlined in Chapter 3.3.
Inter-company exchange: The applicant and several other companies from the sanitary sector are members of CTAC (Chromium Trioxide Authorisation Consortium), the industry consortium of 150+ members launched in 2012 to prepare the authorisation of chromium trioxide for the industry. At the time of preparation of the CTAC application for authorisation the sanitary companies already worked together to gather and analyse all necessary information for the three pillars of the authorisation dossier (CSR, AoA, SEA) to represent their industry sector and reflect their critical quality demands (see chapter on FuSchiDec). From that collaboration a working group emerged that came together again in 2017 to join forces for individual applications for authorisation. Each company contributes with its knowledge to develop a consistent awareness regarding the suitability of potential alternatives across the partnering companies.
FuSchiDec Starting in 2012, many companies in Germany organized themselves in the FuSchiDec (Funktionale Schichten mit Dekorativem Charakter) group. This group comprises major German sanitary companies, and companies from the white goods, consumer, and shop outfitting sectors. The FuSchiDec experts quantitatively evaluated a broad range of alternatives regarding their technical and economic feasibility considering promising alternatives, such as Cr(III) electroplating or based on Physical Vapour Deposition (PVD). Information from FuSchiDec formed the basis for the evaluation of potential alternatives in the CTAC application for functional chrome plating with decorative character.
Collaboration with formulators
For around 3 years, the applicant closely collaborates with formulators of Cr(III)-electrolytes. In general, formulators develop and provide the mixtures, which are then used by the applicant for the electroplating step in test lines. Subsequently, the products undergo a test program and depending on the results of the sample parts the composition of the formulation is adjusted after regular exchanges between applicant and formulator. Available results obtained from this collaboration have been considered for the assessment of alternatives.
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5.1.2 Data searches The applicant is a member of CTAC founded in 2012. The information on R&D and technical assessment of alternatives data provided is based on the applicant’s own investigations and in-house experience as well as information from the exchange within the sanitary sector working group that emerged from CTAC, and information collected in CTAC. Furthermore, searches for publicly available documents were conducted to ensure that all potential alternative processes to chromium trioxide based electroplating applications were considered in the data analysis.
5.1.3 Consultations Discussions with technical experts from the applicant’s side as well as of the other working group members were carried out to get an overview of experience with the alternatives, and completeness and prioritisation of critical parameters for their specific processes and the minimum technical requirements. Detailed material was provided on the R&D activities that were conducted over the last years. From these meetings and materials, a summary on the completeness and experience with the alternatives, specific processes and the key requirements for the use of functional chrome plating for sanitary applications were elaborated. At this stage of the data analysis, some alternatives were screened out after bilateral discussions with the companies, based on confirmation that technical and economic limitations clearly argue against their use as potential alternative to chromium trioxide. To verify data and to obtain further detailed quantitative information, more focused technical questions were sent out and discussed with the experts. Final data analysis led to the formation of a shortlist of alternatives. In summary, the categorized table of alternatives listed below is the outcome of extensive literature and in-house research, and consultations with technical experts.
5.2 List of possible alternatives The applicant invested extensive effort into the assessment of different technologies that are discussed in the following as alternatives for functional chrome plating with chromium trioxide. Several alternatives were examined over the last years with varying outcomes. Based on their performance the main alternative coating technologies were rated accordingly. In Table 5, all potential alternative coating technologies considered and assessed by the applicant are listed. Based on the technical and economic assessment, the alternatives are categorized in “Shortlisted alternatives” that are subject to further R&D and “Rejected alternatives” that are not considered as potential alternatives for electroplating of sanitary applications as they show clear limitations.
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Table 5: List of plating alternatives categorised.
No. Category Potential alternative 1 Trivalent chromium plating 2a Shortlisted alternatives PVD based processes: PVD metal
2b PVD based processes: Lacquer + PVD + Lacquer 3 Satin anodized aluminium Chromium free electroplating: multi-component coating systems (Cu, Sn, 4 Zn, Ni, Co), gold and platinum electroplating, zinc electroplating
5 Wet lacquering
6 CVD: Chemical Vapour Deposition Rejected alternatives 7 DLC: Diamond Like Carbon
8 Electroless nickel plating 9 Powder Coating (Pulverlack) 10 Cr(III)-PVD
11 Stainless steel (alternative substrate)
The functional principle and full assessment of the shortlisted alternatives (No. 1 – 2b) is described in detail in Chapter 6.2. The specific limitations which led to the exclusion of the alternatives No. 3 – 11 are presented in Section 6.1. Importantly, a potential alternative must fulfil all key functionalities (see Section 3.3) for sanitary applications to ensure quality and customer needs before it can be considered as substitute for chromium trioxide in functional chrome plating. The results presented are based on internal testing and research by the applicant and by companies of the sanitary sector working group.
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ANALYSIS OF ALTERNATIVES
6 SUITABILITY AND AVAILABILITY OF POSSIBLE ALTERNATIVES
6.1 Rejected Alternatives (No. 3 – 11) In this chapter, the technical limitations of the alternatives classified in Section 5.2 as “rejected alternatives” are presented in more detail. The applicant conducted a full technical assessment of these alternate approaches but considered them as not applicable for the substitution of chromium trioxide in functional chrome plating of sanitary products. Therefore, no future R&D efforts will be made for the development of these methods. The technical assessment is based on the key functionalities, which are described in sufficient detail in Section 3.3. The assessment of the alternatives which are not applicable for sanitary applications is presented in Table 6 with their corresponding technical limitations. Table 6: Alternatives not applicable for sanitary applications with corresponding technical limitations. Alternative Method No. Technical Limitations1 (criteria described in Section 3.3) (Main treatment) Substrate compatibility -not compatible with plastic substrates 3 Satin anodized aluminium Corrosion resistance -not sufficient (SST and CASS) Chemical resistance -susceptible to strong alkaline and strong acidic media Surface appearance -does not fulfil the requirements Corrosion resistance -not sufficient (SST according to EN 248) Chromium free electroplating (zinc electroplating, multi- Chemical resistance -susceptible to acidic media 4 component coating system of Wear resistance / -low wear and abrasion resistance (damages after 2000 copper, tin, zinc, nickel, cobalt; abrasion resistance cycles in the Taber abrasion test) gold and platinum electroplating) Surface appearance -does not fulfil the requirements Longevity -not sufficient -depending on layer thickness Corrosion resistance -surface defects after 200 h (SST according to EN 248) Chemical resistance -susceptible to alkaline and acidic media 5 Wet lacquering/ colour painting -low wear and abrasion resistance Wear resistance / abrasion after < 10 cycles abrasion resistance strong degradation after 1000 cycles Surface appearance -does not fulfil the requirements -not compatible with plastic substrates (process temperatures between 200 and 500 °C. ABS plastic Substrate compatibility melting point = 105 °C) CVD - Chemical vapour -not compatible with complex geometric parts and parts 6 deposition with small internal diameters Chemical resistance -not sufficient -not sufficient (it requires the addition of a bright Surface appearance underplate for a bright appearance of the CVD surface) -not compatible with plastic substrates (process temperatures ca. 150 °C) Substrate compatibility - not compatible with parts of complex geometry and parts with small internal diameters -not sufficient (DLC coating applied on brass was 7 DLC: Diamond Like Carbon Chemical resistance completely corroded after 7 days immersion in acidic media) Adhesion -not sufficient - does not fulfil the requirements (it requires the addition Surface appearance of a bright underplate for a bright appearance of the DLC surface) -does not meet the requirements: 8 Electroless nickel plating Corrosion resistance initial corrosion after 72 h (brass, plastic and zinc die cast)
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ANALYSIS OF ALTERNATIVES
Alternative Method No. Technical Limitations1 (criteria described in Section 3.3) (Main treatment) corrosion protection (300 to 500 h in NSST) when layer thickness > 25 µm (chrome coating thickness is between 0.2 and 2 µm) Chemical resistance -not sufficient Ni-leaching -exceeds the Ni threshold values Surface appearance -does not fulfil the requirements -not compatible with plastic substrates (process temperatures between 140 and 200 °C) Substrate compatibility -Powder coating on zinc die-casting can reduce the strength and the stiffness on the substrate (at temperatures > 100°C) 9 Powder coating - does not fulfil the requirements: Corrosion resistance brass < 200 h (SST according to EN ISO 9227) Chemical resistance -susceptible to alcohol, solvents and toothpaste Wear resistance / -low wear and abrasion resistance (abrasion after < 10 abrasion resistance cycles) Surface appearance -does not fulfil the requirements - not sufficient: 10 Cr(III) - PVD Corrosion resistance brass with Cr(III) and PVD coating (noble metal) < 200 h (SST according to EN ISO 9227) -it is not a technically feasible alternative to chromium Substrate compatibility trioxide electroplating on plastic substrates -Depending on assembly: separate stainless-steel parts: 300h Corrosion resistance stainless-steel parts combined with other metal 11 Stainless steel (alternative component: < 72h substrate) Chemical resistance -susceptible to strong acids and chlorine based chemicals Wear resistance / -not sufficient (from 200 to 400 HV) abrasion resistance Surface appearance -does not fulfil the requirements Longevity -not sufficient 1 Only exclusion criteria are mentioned
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ANALYSIS OF ALTERNATIVES
6.2 Shortlisted alternatives The three alternatives assessed in this chapter are considered the most promising ones, where considerable R&D efforts have been carried out by the applicants and other companies in the sanitary industry. They either show technical limitations when it comes to the demanding requirements of the sanitary sector, and/or have economic disadvantages at the current stage. To assess the feasibility of the alternatives, colour coded summary tables are included in the document. The colours are as follows:
Colour Explanation Not sufficient - the parameters/assessment criteria do not fulfil the requirements The parameters/assessment criteria fulfilment not yet clear Sufficient - the parameters/assessment criteria do fulfil the requirements No data available The alternative assessments each comprise a non-exhaustive overview of general information on substances used within the alternatives and alternative processes, as well as the risk to human health and environment. These tables are provided in Appendix 1.
Importantly, a potential alternative method must fulfil all key functionalities for sanitary applications to ensure quality and customer needs before it can be considered as substitute for chromium trioxide in functional chrome plating.
6.2.1 ALTERNATIVE 1: Trivalent chromium electroplating
6.2.1.1 Substance ID and properties / process description Electroplating with trivalent chromium electrolytes forms a coherent metallic chrome coating on the substrate applied. The substrate presents the cathode and an inert, often graphite anode is used to induce an electrical current. The substrate is immersed in Cr(III) plating solution (electrolyte) containing dissolved Cr(III) salts, typically with additives such as ammonium salts as complexing agents, and boric acid or borate salts as buffering agents. During the electroplating process, the dissolved Cr(III) cations are reduced to metallic chrome and build up the coating (electrodeposition). The composition of the Cr(III) electrolyte depends on the surface treatment and the application which is to be replaced. For sanitary applications, the currently favorable electrolyte for testing is chromium(III) sulphate since the colour consistency of the coated products is higher compared to the ones obtained with chromium(III) chloride. A non-exhaustive overview of general information on substances used within this alternative and the risk to human health and the environment is provided in Appendix 1.
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ANALYSIS OF ALTERNATIVES
6.2.1.2 Technical feasibility General assessment: The transition from Cr(VI)-based to Cr(III)-based electroplating is technically the closest drop-in alternative, as generally similar equipment with wet-in-wet bath technology can be used for both electroplating processes. Nevertheless, the transition from chromium trioxide to Cr(III) cannot simply be performed by changing the plating electrolyte. In general, results obtained from tests on different types of substrates are considered to be applicable for all substrates of interest as the multi-layer system with a final chromium coating is comparable for all substrates. Corrosion resistance: The corrosion resistance was tested independently by different companies. Salt spray tests (NSST, according to EN ISO 9227, EN 248) and Kesternich tests according to EN ISO 6988, DIN 50018 were conducted. With regards to the salt spray test (EN ISO 9227, EN 248) Cr(III)-coated (chloride based electrolyte) sanitary fittings made of brass were treated applying the cycle 100 h NSS, storage for 48 h at 35 °C, 100 h NSS and subsequently evaluated according to EN ISO 10289. After 200 h NSS treatment corrosion with varying areas of defects was observed in most parts (see Table 7 for examples). Another 200 h salt spray test (EN ISO 9227) shows the difference in corrosion resistance of Ni/Cr(VI) and Ni/Cr(III) (sulphate based electrolyte) coated brass parts. While only few and little spots within the evaluation limits according to EN ISO 10289 can be observed for the Cr(VI) coated brass part, several spots and discoloration that are not acceptable according to DIN EN 10289 can be observed for the Cr(III) coated part (Figure 7). A salt spray test with Ni/Cr(III) coated brass parts (sulphate based electrolyte) caused milky iridescent spots at the side surfaces and edges as well as single pits with white crystalline precipitations at the inner surface. The outer surface of the test item was free of blisters, pits and cracks. Finally, a salt spray test (EN 248) was performed with Cr(III) coated thermostat bodies made of brass and spotting of varying degree was observed. Results of a Kesternich test (DIN 50018, EN ISO 6988) conducted with Cr(III) coated (chloride based electrolyte) sanitary tap parts made of brass showing areas of defects of varying degrees after 1 - 3 cycles are presented in Table 8. Another Kesternich test with Ni/Cr(III) coated brass parts (sulphate based electrolyte) revealed as well areas of defects of varying degrees after 1 – 3 cycles. After the third cycle the test item showed dark discoloration at around 25 % of the total surface where flaking of the top layer was observed. Further, the test item had fine cracks at the inner surface. Along the cracks and the edges, the test item showed single black dots and green crystalline precipitation (Figure 8). In summary, the corrosion resistance of some tested coatings clearly failed the sanitary requirements, at the current stage of development. In any case, testing will continue to stay on track with new developments from chemical providers and process development, particularly with respect to the most promising sulphate based Cr(III) electrolytes.
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ANALYSIS OF ALTERNATIVES
Table 7: NSS-Test with Cr(III)-coated sanitary fittings made of brass.
200 h NSS-Test ISO 9227; Corrosion of the coating: 3 x 5 -10 % area of defect, 2 x 2.5 – 5 % area of defect, 2 x 1.0 – 2.5 % area of defect
Figure 7: 200 h salt spray test (EN ISO 9227) with Cr(VI) (left) and Cr(III) (right) coated brass parts.
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ANALYSIS OF ALTERNATIVES
Table 8: Kesternich-Test with Cr(III) coated sanitary tap parts made of brass. Test items after the test (Kesternich test ISO 6988, DIN 50018), 3 cycles After 1st cycle: > 1.0 – 2.5 % area of defects (left) and > 5.0 – 10 % area of defects (right)
After 2nd cycle: > 25 – 50 % area of defects (left) and > 10 – 25 % area of defects (right)
After 3rd cycle: > 25 – 50 % area of defects (left) and > 10 – 25 % area of defects (right)
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ANALYSIS OF ALTERNATIVES
Figure 8: Kesternich Test of brass coated with Ni/Cr(III) after 3rd cycle. Wear resistance / abrasion resistance: The abrasion resistance of Cr(III) coated parts was tested in taber abrasion tests. The test performed with a dry felt cloth resulted in small scratches (thin hairlines), but without larger scratches or extensive abrasion. Other test results revealed that the Cr(III) coated surface was scratched after <50 cycles (while requirements are up to 10,000 cycles without scratches/damages). Another test investigated the abrasion resistance of Cr(III) coated brass (sulphate based electrolyte). Therefore, 100 double strokes with a loading of 10 N were applied to the surface of the test object with different media (acidic cleaning agent, basic cleaning agent, uric acid, acidic acid 10%, ammonia 10%, hydrogen peroxide 5%, saturated curd soap solution, acetone). The assessment of the test item after treatment with curd soap solution revealed a significant attack of the coating and the surface was matt and scratched. However, no changes of the surface were observed for other Cr(III) based brass samples that were treated in the same way. In addition, an abrasion test with four Cr(III) and three Cr(VI) coated parts was performed at which a polish was applied on the sample surface until removal of the chromium layer. Visual evaluation of the samples proved that the wear resistance of Cr(VI) coated parts was significantly higher than the one of Cr(III) coated parts. Specifically, significant attack of the chromium layer (>50 % destroyed surface compared to total surface treated) was observed for Cr(III) coated parts after 5,000, 6,000, 8,000 and 13,000 cycles, respectively, and for Cr(VI) coated parts after 28,000, 36,000 and 41,000 cycles, respectively. Adhesion: The adhesive properties of Cr(III) based metal coatings on different kind of substrates (metals and plastic) were tested. In cross-cut tests, the adhesive properties in general sufficiently fulfilled the sanitary requirements. Chemical resistance: The chemical resistance of metallic chrome coatings from a Cr(III) electrolyte tested by continuous immersion in household cleaning agents (such as vinegar essence or commercially available products), differs for the different electrolytes. Like corrosion resistance, the tested coatings clearly failed the sanitary requirements for chemical resistance (by showing severe surface corrosion) or marginally met these requirements (only showing slight corrosion, single attack points). The chemical resistance is especially low when exposed to acidic cleaning agents. For all tested parts, besides one test where the cleaning agent test with chromium(III) coated brass thermostat bodies was successfully passed, the chemical resistance was lower compared to the metallic chrome coatings from chromium trioxide based electroplating and did not sufficiently fulfil the applicant’s requirements at the current stage of development. Substrate compatibility: Trivalent chromium plating is generally applicable to all commonly used substrates, such as die cast, brass, copper and plastic substrates. For all substrates, underplates are
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ANALYSIS OF ALTERNATIVES required as barrier between the electrolytically plated coating and the substrate to create a corrosion resistant and aesthetic surface. Temperature change resistance / Heat resistance: No data are available, but with regards to this key functionality, no critical limitations are expected for Cr(III)-based metal coatings. Colour consistency: The chromium(III) sulphate-based metallic chrome coating is characterized by a shade similar to a functional chrome coating with chromium trioxide. The yellowish/brownish shade of the coating is caused by iron ions (for example coming from the rack, the substrate, or the production surroundings) that enter the Cr(III) electroplating bath as impurities. The iron corrodes once in contact with atmospheric oxygen, resulting in a yellowish/brownish colour of the coating. Even the smallest quantities of iron impurities can lead to this effect. At present, it is not possible to adequately maintain process conditions that prevent this yellowish shade. As of today, conventional Cr(VI) based plating solutions are generally used long- term (a chromium trioxide electrolyte can be used for more than 5 years, without being renewed completely). The longer the same Cr(III) plating solution is used, the more impurities are accumulated that may affect the final colour of the product. Consequently, creating a uniform surface appearance of all products plated in such Cr(III) plating solution over the lifetime of the bath is challenging. Besides the yellowish colour, trivalent chrome plated products from different platers are not of the exact same colour. Different trivalent chromium coated parts assembled together, will show a slightly different colour and will not match exactly, which is not acceptable for customers. The yellowish colour may also occur for example after longer transport times of plated parts, even if the products left the facility coated with an adequate colour. This issue is mainly related to corrosion. Importantly, this surface aging also occurs during normal usage of installed products, with the effect that in case of refurbishment or repair, new parts would not match the established inventory. All in all, the colour consistency of Cr(III) plated parts is currently not sufficient for sanitary applications. Surface appearance: No data are available, but with regards to this key functionality, no critical limitations are expected for Cr(III) based metal coatings. Ni leaching: No data available. Long-term tests are required to determine potential nickel leaching from Cr(III) based coatings. Sunlight resistance: No data are available, but with regards to this key functionality, no critical limitations are expected for Cr(III)-based metal coatings. Process conditions: Trivalent chromium baths are much more sensitive to metallic impurities and to the acidity of the bath than conventional chromium trioxide plating baths. Even small deviations in the process conditions can strongly influence the deposition, the layer quality and the final appearance. Consequently, establishing a reliable process for metallic chrome layers from a Cr(III) electrolyte of reproducible quality (colour, corrosion resistance, thickness, hardness, etc.) is challenging and the Cr(III) based plating process requires careful handling. An ion exchanger and several additional basins/baths are needed to ensure adequate rinsing to reduce the transition of impurities to the plating baths as much as possible.
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ANALYSIS OF ALTERNATIVES
Conclusions: Large R&D efforts have been made and are still on-going to establish Cr(III) electroplating as an alternative to chromium trioxide electroplating. The performance of Cr(III) based metallic chrome coatings is constantly improving as most recent test results demonstrate. Despite these improvements, Cr(III) derived coatings still have technical limitations particularly when it comes to corrosion resistance and color consistency. Furthermore, long-term tests are required for nickel leaching and an evaluation basis that allows to prove conformity with the drinking water directive is still missing. Given the very sensitive plating baths which require extensive maintenance, the long-term use of the bath electrolyte critically influences the quality of the coated parts.
Wear resistance Temp. change Corrosion Chemical Substrate / abrasion Adhesion resistance / heat resistance resistance compatibility resistance resistance varying, mostly varying, mostly
failed failed
Colour Surface Prevention of Sunlight Process consistency appearance nickel leaching resistance conditions
6.2.1.3 Economic feasibility Exchanging the Cr(VI) process with Cr(III) electrolytes comes with important process changes that influence the economic feasibility:
Costs for modification of production lines: - Larger plating lines necessary (ca. 4 additional baths); - Complex task of inclusion into current lines, if possible at all; - Additional wastewater treatment measures are required (organic complexing agents and stabilisers necessary for trivalent chromium electroplating); - Additional baths for adequate rinsing (adequate rinsing is required to minimise the carryover of impurities in the bath process); - Additional process equipment is required for cooling of the Cr(III) bath. The plating process is strictly serial, and the spin-off of these additional baths adjacent to the line is not possible, as the parts are moved automatically by a transportation system which can only move along the galvanic baths.
Operational costs: - Higher chemical costs; - Higher scrap rate; - Higher analytical efforts (maintaining Cr(III) bath quality takes about 14 hours per week, compared to 2 hours per week for the Cr(VI)-bath); - Higher reclamation costs (e.g. due to colour inconsistencies).
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ANALYSIS OF ALTERNATIVES
Indications were made that operational costs only for the chromium(III) bath (e.g. chemicals, analytical effort) are expected to be three times higher than for chromium trioxide electroplating. However, costs per part using a Cr(III) based process are estimated to be up to 30% higher considering the whole plating process. Despite the challenging process and operational issues, there are a number of benefits comparing Cr(III) with chromium trioxide electroplating (NEWMOA, 2003). With regard to air emissions, the trivalent chromium process releases less chromium mist into the air due to a higher cathode efficiency than chromium trioxide plating. In addition, this mist is much less toxic compared to chromium trioxide electroplating. This facilitates risk management measures and operational conditions with regards to air emissions. As the typical Cr(III) plating bath has a lower chromium concentration, there is less total chromium in the wastewater stream. In addition, since the wastewater contains Cr(III) cations, no reduction step from Cr(VI) to Cr(III) is necessary (which also eliminates the use of potential hazardous or harmful reducing agents). By the use of Cr(III) electroplating, approximately thirty times less sludge is produced, for example because the anode is not decomposed. This results in reduced costs for handling and disposal of hazardous waste. However, as organic complexing agents and stabilizers are used in trivalent chrome electroplating, these substances will likely interfere with the wastewater treatment and additional wastewater treatment measures, such as oxidative destruction of the organic components and depuration of boron (in case of boron based additives), would be required. Another problem concerning air quality may occur; if the treated wastewater from the Cr(III) electroplating is alkalized up to pH 9, as due to the ammonium concentration, ammonia can be formed, which can endanger the safety of workers. All the necessary measures will, in contrast to the described cost reduction, lead to increased costs for wastewater treatment (running costs and investment costs for systems engineering). As a result, there are no costs benefits from the transition of chromium trioxide to a Cr(III) electrolyte with respect to wastewater treatment. Furthermore, higher costs for the used chemicals (trivalent chromium based solutions are more expensive than chromium trioxide plating solutions) and the used anodes should be taken into account. In addition, large analytical efforts must be made to maintain the quality of the electrolyte and to minimize quality loss caused by impurities in the bath: Chromium trioxide electrolytes require 2 hours analytical control per week, while the Cr(III) plating baths requires 2 h analytical control per day. Furthermore, ancillary equipment, such as ion exchangers for the removal of impurities, need to be added as well. Some of the above described economical drawbacks may be covered to some extent by economic benefits of Cr(III) electroplating. The lower current density of the Cr(III) plating process is less energy consuming and results in reduced energy costs. As the throwing power of trivalent chromium plating is generally better, more parts can be placed on the racks resulting in a higher production rate and throughput of parts. Significant investment is needed if the additional baths do not fit in the building. Besides the actual reconstruction measures of the production site this step may comprise approval procedures for the reconstruction and the new process as well as identification and development of suitable land. Further, the increased effort (e.g. additional baths and equipment) involves a higher potential for defects leading to higher numbers of scrap rates and reclamations and thus higher costs.
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ANALYSIS OF ALTERNATIVES
6.2.1.4 Reduction of overall risk due to transition to the alternative Based on the available information on the substances used within this alternative (see Appendix 1.1.1), the most promising and currently used substance chromium(III) sulphate is not classified by the vast majority of notifiers, whereas the worst-case classification of some notifiers is Acute Tox. 4, Skin Corr. 1, Skin Sens. 1, Eye Dam. 1 and Aquatic Chronic 2. In general, the trivalent electroplating processes are less toxic than chromium trioxide plating due to the oxidation state of the chromium. Cr(III) solutions do not pose serious air emission issues, but still pose the problems of disposal of stripping solutions (depending on the type of stripping solution) and exposure of staff to chrome dust during grinding. In addition, there is a certain risk of Cr(VI) being generated during the plating process. This is why appropriate security precaution and process management must be adopted to prevent the formation of Cr(VI). The bath chemistry typically also comprises a high concentration of boric acid, which is a SVHC substance (toxic for reproduction) included on the candidate list and currently on the 6th recommendation for inclusion in Annex XIV. Another aspect to be mentioned is the significantly increased aerosol-formation during the Cr(III) process due to the inferior current yield compared to the Cr(VI) process. Despite these facts, the transition from chromium trioxide to trivalent chromium constitutes a shift to less hazardous substances. However, as at least one of the used alternative substances is itself classified for mutagenicity and carcinogenicity, any replacements will need to be carefully evaluated on a case by case basis.
6.2.1.5 Availability The Cr(III) electroplating techniques, as well as different kinds of Cr(III) electrolytes are commercially available. Cr(III) coated parts for sanitary purposes are available on the market, with customer demands that are not necessarily in line with the requirements illustrated in this AoA, in particular when it comes to longevity of the parts. Despite still increasing efforts in R&D and performance improvements over the last years, Cr(III) plated parts are not qualitatively comparable to Cr(VI) plated parts for sanitary applications and do not fulfil the critical quality requirements of the applicant and its customers. Especially in relation to long-term high-quality applications, for example in hotels or other places where the installations are highly frequented, the technical limitations are even more obvious, which is not acceptable from a customer perspective.
6.2.1.6 Conclusion on suitability and availability for trivalent chromium electroplating At the current stage of development, trivalent chrome electroplating is not a technically feasible alternative to chromium trioxide electroplating. Coatings from Cr(III) electrolytes do not sufficiently fulfil the applicant’s critical requirements for their applications, especially regarding corrosion resistance and colour consistency. Despite these facts, some Cr(III) coated products have been recently used for sanitary applications, but clearly do not fulfil the specific high-quality requirements for the applicants’ sanitary
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ANALYSIS OF ALTERNATIVES applications. No long-term performance has been investigated so far. In conclusion, intensive R&D on the technical feasibility of Cr(III) based coatings is still necessary and ongoing. However, it is not expected that Cr(III) based electroplating can be industrially used as a general alternative to chromium trioxide electroplating at required capacities within the next 12 years.
6.2.2 ALTERNATIVE 2 a: PVD based processes - PVD metal
6.2.2.1 Substance ID and properties / process description Physical Vapour Deposition (PVD) is the general name for a variety of vacuum processes. Compared to functional chrome plating, the PVD-based processes require fundamentally different technology, but a chemical etching pre-treatment is not required. The PVD process starts with placing the coating material in solid (or rarely in a liquid) form in a vacuum or low-pressure plasma environment. The coating material is vaporized by an electric arc or electron beam (TURI, 2006) and deposited, atom by atom, onto the surface of the material to be coated to build up a thin film. Nitrogen, oxygen or methane are used as gases, while argon is used for the formation of the plasma phase. Vaporizing of the coating material may be conducted by one of the following methods. Ion assisted deposition / ion plating: This is a combined method as a film is deposited on the substrate while ion plating bombards the depositing film with energetic particles. The energetic particles may be the same material as the depositing film, or may be a different inert (argon) or reactive (nitrogen) gas. Ion beam assisted deposition (IBAD) describes a process in a vacuum environment where the ions originate from an ion gun (TURI, 2006). Sputtering: This process is a non-thermal vaporization where the surface atoms on the source material are physically ejected from the solid surface by the transfer of momentum from bombarding particles. Typically, the particle is a gaseous ion accelerated from low pressure plasma or from an ion gun (TURI, 2006). Low temperature arc vapour deposition (LTAVD): This is a low temperature PVD based technique applying metal coatings at ambient temperatures. The parts to be coated are placed in the vacuum chamber and spun around the metallic source of the coating (the cathode). By applying a vacuum to the chamber, a low-voltage arc is created on the metallic source and the metal is evaporated from the arc at temperatures of around 100 °C. The conditions for PVD coatings are process specific and dependent on the substrate and applied coating. PVD coating temperatures are typically in the range between 180 °C to 450 °C. The coating time depends on a number of factors, such as coating thickness, spinning time of the part in the vacuum chamber, and the geometry of the part to be coated. The PVD coating time for metal substrates is typically in the range of between 20 and 30 minutes. In general, the throughput of parts depends on the size of the vacuum chamber and the geometry of the parts. PVD layers can be deposited either as a single layer or by multi-layer deposition, with up to 2000 (very thin) single layers. The typical thickness of PVD coatings with decorative character lies between 0.1 and 0.5 µm.
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ANALYSIS OF ALTERNATIVES
The following PVD based processes are discussed below: - PVD metal: vacuum based deposition of a metal coating/layer
o PVD chrome: vacuum based deposition of a chrome coating; o PVD aluminium: vacuum based deposition of an aluminium coating. - Lacquer + PVD systems (discussed in the following Chapter 6.2.3)
o Lacquer + PVD + lacquer: three-layer system with an initial lacquer applied on the substrate, a subsequent PVD layer and a, typically clear, topcoat;
o Lacquer + PVD: two-layer system with an initial lacquer followed by a PVD layer. Some typical PVD coatings, which can either be applied as stand-alone PVD metal or as PVD layer in case of a lacquer + PVD system, are nitride based types such as titanium nitride (TiN), titanium carbon nitride (TiCN), titanium aluminium nitride (TiAlN), chromium nitride (CrN) and zirconium nitride (ZrN), or carbide based such as tungsten carbide (WC), zirconium carbide (ZrC), zirconium oxide carbide (ZrOC), silicon carbide (SiC) or titanium carbide (TiC). The CrN creates the PVD chrome layer, while the TiAlN is responsible for PVD aluminium. A non-exhaustive overview of general information on substances used within this alternative and the risk to human health and the environment is provided in Appendix 1.1.2. This overview is focused on selected substances for the PVD process.
6.2.2.2 Technical feasibility - PVD metal R&D efforts have already been conducted and are still ongoing on the technical feasibility of PVD based processes. Numerous test results of PVD metal on different substrates were provided and assessed in this AfA. Corrosion resistance: In general, there is an increased risk of corrosion for layers consisting of different materials. When surface defects occur, the layer with the lowest electrochemical standard potential can dissolve. Sensitive substrates such as zinc die-cast always have to be protected by a copper layer in order to enable the deposition of another layer. Additionally, a nickel layer (low standard potential) that generates brightness of the final products is required, which may itself be protected by a chromium layer. On top of the chromium layer a metal coating can be deposited by PVD. Provided that the final layer has a high standard potential and reveals slight defects the base metal dissolves first under exposure to humidity. An initial supporting layer is necessary - especially on brass, different kinds of die cast and plastic substrates - as the PVD coating does not provide corrosion resistance to the base substrate itself. This supporting layer is typically applied by electroplating. PVD nitride coatings are reported to be essentially inert and do not corrode easily. However, they do not provide the same corrosion resistance as thicker metallic chrome coatings. Especially once the coating is scratched or damaged, the corrosion protection provided by the layer degrades faster compared to chrome layers. This effect depends on several factors in the course of the deposition of the PVD coating, such as used gases and gas composition, coating time, and temperature. A major problem with PVD coatings is that the substrate can easily be affected by corrosion in cases where
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ANALYSIS OF ALTERNATIVES for example moisture migrates between the coating and the substrate. As stated above, a supporting layer must be applied prior to the application of a PVD metal coating, as PVD coating does not provide sufficient corrosion resistance to the base substrate itself. By applying supporting layers, the corrosion resistance of the PVD metal coating is increased. Salt spray tests were conducted with PVD coated brass thermostat bodies. Significant corrosion of the PVD coating can be observed, the requirements for corrosion resistance are not fulfilled (Figure 9).
Figure 9: Salt spray test with PVD coated brass thermostat bodies. In general, the corrosion resistance of PVD based coatings is highly dependent on the kind of coating and coating system (including the, potentially necessary, supporting layer). Compared to a metallic chrome coating derived from chromium trioxide, the corrosion resistance of PVD based coatings is does not to meet the requirements for corrosion resistance. Wear / abrasion resistance: Test results provided on PVD metal coatings also reveal problems with the abrasion resistance of the coatings. Testing of PVD chrome compared to Cr(VI) derived coatings showed that the PVD chrome 0.5 µm coating has a strong tendency of damage at the edges under mechanical stress, while this tendency is much smaller for the PVD chrome 0.25 µm coating. While the low hardness of the PVD coating is considered not to be the reason for abrasion problems, it is potentially the high layer thickness of the coating that increases internal stress. The abrasion resistance of PVD based coatings is highly dependent on the kind of coating and coating system applied. It is technically challenging to find the optimal balance between layer thickness and internal stress that enables the formation of an abrasion resistant coating in line with the sanitary requirements. In conclusion, the abrasion resistance of PVD based coatings is insufficient at the current time. Adhesion: No data are available, but with regards to this key functionality, no critical limitations are expected for PVD-based metal coatings. This key functionality will be tested only in case satisfactory results are obtained for the main key functionalities (e.g. corrosion resistance). Chemical resistance: Comparative tests were performed between metallic chrome coating (Cr(VI) (with a thickness of the metallic chrome layer of 0.5 µm) and a PVD chrome coating (with 0.5 and 0.25 µm coating thickness). These tests are performed with a thinner thickness than usual, because PVD chrome was applied as top coating on metallic chrome coating. The test results showed stronger corrosion for the PVD chrome samples, while the tested electroplated chrome coatings showed almost no corrosion at the edges.
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ANALYSIS OF ALTERNATIVES
Strongest corrosion was found at the edges for the 0.5 µm PVD chrome coating, in the cleaning agent spray test after 14 days (mostly acidic based commercially available products) and in the 7 days continuous immersion test in vinegar essence. The 0.25 µm PVD chrome coating showed only slight corrosion at the edges after both tests. As the layer thickness of the three types of chrome coatings is comparable, it is considered not to be the reason for the stronger corrosion of PVD chrome 0.5 µm. As the application of a PVD chrome layer is technically much more difficult compared to an electroplated chrome coating process, the process parameters highly influence the performance of the final coating. By using the correct parameters, it is possible that PVD coatings can meet the requirements for corrosion and abrasion resistance. Besides PVD chrome coatings, other kinds of metal coatings for different aesthetic purposes can be applied by PVD technique, amongst others bronze, gold or dark chrome (surfaces for special applications). The test results provided on these kinds of PVD metal coatings indicate problems with corrosion and chemical resistance, potentially resulting from issues with the applied layer thickness of the coating. Coatings tested with different test methods showed that the chemical resistance of PVD based coatings is highly dependent on the kind of coating and the coating system (including the potentially supporting layer). Large technical efforts are necessary to achieve a chemical resistant coating as required by the sanitary sector. Compared to a metallic chrome coating using chromium trioxide electroplating, PVD metal shows insufficient performance regarding chemical resistance. Substrate compatibility: Brass, copper, die-cast zinc and plastic substrates can be applied with a PVD coating. Plastic substrates are coated at low-temperature PVD processes. Temperature change resistance / heat resistance: PVD metal coatings (without lacquer) were found generally to be in accordance with company specific requirements (for example 300 cycles of 80 °C to 20 °C without significant defects). In general, temperature change resistance is - again - dependent on the PVD coating, which is a clear disadvantage compared to a metallic chrome coating from chromium trioxide. Currently the temperature change resistance of PVD based coatings is considered as not meeting the overall requirements. Colour consistency: In general, the colour of PVD based coatings is characterized by the deposited metal. PVD chrome is considered as most comparable to metallic chrome coatings from a chromium trioxide plating solution. Due to the different kinds of metal which can be used for a PVD coating, PVD chrome is considered the most promising PVD based process with regard to aesthetic appearance. All other kinds of PVD based coatings are not of the same aesthetic appearance. In general, it is possible to achieve the colour shade of Cr(VI) with PVD. However, there are problems with the reproducibility of the shade, since it is highly dependent on the gases used for the PVD process. Adjustment and exact steering of the gases is extremely complex and requires high experience and expertise with the PVD process. Impurities in the gases have immediate effect on the surface. Therefore, it is extremely challenging to achieve the same shade of colour even within the same facility. To achieve comparable results across different suppliers is even more challenging.
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ANALYSIS OF ALTERNATIVES
Finally, the coated surface does not have the same metal feeling as metallic chrome coatings applied by chromium trioxide electroplating have. Surface appearance: No data are available, but with regards to this key functionality, no crucial limitations are expected for PVD-based metal coatings. This key functionality will be tested only in case satisfactory results are obtained for the main key functionalities (e.g. corrosion resistance). Ni leaching: Nickel leaching is only relevant if nickel is contained in the PVD layer system. In this case respective tests would have to be conducted. Sunlight resistance: No data are available, but with regards to this key functionality, no critical limitations are expected for PVD-based metal coatings. This key functionality will be tested only in case satisfactory results are obtained for the main key functionalities (e.g. corrosion resistance). Process conditions: PVD coatings, which are directly applied on the substrate, require an atomically clean surface because they are highly sensitive to contaminants (e.g. water, oils and paints) on the surface to be coated. Inadequate or non-uniform ion bombardment leads to weak and porous coatings and is the most common failure in PVD coating (Legg, 2003). In most cases, ion bombardment during coating is responsible for a high internal stress. This stress accelerates with increasing coating thickness and can lead to delamination of the coating. Therefore, PVD layers are optimally applied with a thickness of about 1-3 µm (in rare cases about 15 µm). The implementation of the PVD technology requires an adaption of the production parameters for each single part to be coated keeping in mind that there are more influencing variables for PVD coatings than for coatings with chromium trioxide. Thus, the adaption of the PVD process for more than xxxxxxxxxxxxxxx typically coated at the applicant would result in significant time and cost efforts. In other industry sectors, PVD machines can be designed and optimised for one specific part, which subsequently allows coating of high volumes of this specific part. However, this is not possible in the sanitary industry where significantly larger amounts of different parts often in low quantities are produced. Conclusion: PVD metal coatings do not represent a technically feasible alternative to chromium trioxide electroplating for sanitary applications at the current stage. The colour of PVD chrome is the most comparative coating of all the different PVD processes to metallic chrome coatings derived from Cr(VI). The other process alternatives are neither comparable nor competitive to the bright silvery-bluish appearance of metallic chrome coatings applied by electroplating with chromium trioxide. For the key functionalities such as corrosion resistance, chemical resistance, abrasion resistance and temperature change resistance, additional technical efforts are necessary to develop a coating system potentially able to meet the sanitary requirements. At the current stage of development, none of the PVD based coatings is able to provide all the required functionalities.
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ANALYSIS OF ALTERNATIVES
Wear resistance Temp. change Corrosion Chemical Substrate / abrasion Adhesion resistance / heat resistance resistance compatibility resistance resistance depending on
deposited metal
Colour Surface Prevention of Sunlight Process consistency appearance nickel leaching resistance conditions depending on
deposited metal
6.2.2.3 Economic feasibility Costs for modification of production lines: In all cases, very high investments for setting up PVD based production lines at an adequate size to guarantee the sufficient throughput of parts are necessary. In case of transition to a PVD based alternative, the installation of completely new production lines is required, as the PVD based process cannot be operated in the same installations. In addition, technical knowledge of the operating staff is required. In addition to investment costs, the vacuum chamber must have a sufficient size for the respective parts (for example kitchen fittings, shower fittings, etc.) and accommodate the complexity of the parts. In general, the need of a vacuum chamber limits the size and the type of parts that can be coated. PVD, a line-of-sight process, is not suitable for complex geometries and large parts. The complexity and size of the parts to be coated with PVD has to be taken into account when planning the vacuum based process. Operational costs: Indications were made stating that the operational costs for a PVD metal coating (for example as additional coating on top of a chromium trioxide electroplated metallic chrome coating) are at least five times higher (depending on geometry of the parts) compared to electroplating using chromium trioxide. Further factors are that the coating costs for PVD metal are significantly higher, because no wet-in- wet coating is possible, and at the current stage full automation is not possible. Additionally, due to the complexity of PVD based systems, maintenance is very high.
6.2.2.4 Reduction of overall risk due to transition to the alternative As the alternative is not technically feasible, only classification and labelling information of substances and products were reviewed for comparison of the hazard profile. Based on the available information on the substances used within this alternative (see Appendix 2.2.2), titanium nitride would be the worst case with a classification as Flam. Sol. 2, Skin Irrit. 2 and Eye Irrit. 2. As such, transition from chromium trioxide - which is a non-threshold carcinogen - to this substance would constitute a shift to less hazardous substances.
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6.2.2.5 Availability Different PVD based processes have been tested and R&D is still ongoing, PVD coatings are not meeting the requirements from the applicant but are already in use for single applications in different sectors. In cases where PVD is used in the sanitary sector it is to date combined with a Cr(VI)-based sub-layer. The applicant uses PVD metal coatings as topcoat on top of metallic chrome coatings applied by Cr(VI) electrolytes for special functional (hardness) or special aesthetic (“steel optic”) purposes. However, these are niche applications (special surfaces) and clearly do not work without the underlying electroplated metal layers. xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx. PVD metal coatings are currently not a stand-alone coating technique. In general, the availability of sufficient PVD machines in a short-term to cover the applicant’s coating capacity is doubtful, especially in case of several requests at the same time. The transition to a PVD based alternative would require high investments to provide sufficient coating capacities for the large number of parts that have to be coated. In addition, the PVD coating technique is generally limited to smaller parts (depending on the size of the vacuum chamber) and limited geometries (inner diameters may be problematic as well as non-flat geometries).
6.2.2.6 Conclusion on suitability and availability of PVD metal processes At the current stage of development, PVD metal processes are not a technically feasible alternative to chromium trioxide electroplating. At the current stage, coatings from PVD processes do not sufficiently fulfil the applicant’s critical requirements, especially regarding corrosion resistance, wear resistance / abrasion resistance, chemical resistance and process conditions. Therefore, large technical efforts are necessary for the development of a coating or a coating system that is potentially able to meet the overall requirements of the sanitary sector. To conclude, due to the insufficient technical performance, very high investment and production costs and uncertainties regarding availability of PVD machines and applicability to the broad product spectrum of the applicant (different sizes and geometries), the PVD technology cannot be considered as suitable alternative to chromium trioxide based electroplating.
6.2.3 ALTERNATIVE 2 b: PVD based processes - lacquer + PVD + lacquer
6.2.3.1 Substance ID and properties / process description General information on the process is described in Chapter 6.2.2.1. Regarding lacquer + PVD systems, different kinds of systems are commercially available, either comprising a three-layer lacquer + PVD + lacquer, or a two-layer lacquer + PVD system.
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ANALYSIS OF ALTERNATIVES
All systems start with an initial lacquer layer. Depending on the respective lacquer + PVD system, this is typically a powder lacquer, a wet lacquer or an UV-lacquer. With regard to the two-layer systems, most typically an UV lacquer is used. The subsequent PVD layer is applied on top of the lacquer base by sputtering, with a typical (very thin) thickness in the range of 0.1 to 0.2 µm. Regarding the different lacquer + PVD systems, the PVD layer is either a metallic aluminium or a metallic chrome coating. The two-layer lacquer + PVD coating is most commonly based on a PVD chrome layer. In case of a three-layer lacquer + PVD + lacquer coating, a final coating (powder, wet or UV lacquer) is applied.
6.2.3.2 Technical feasibility - lacquer + PVD systems R&D efforts have been conducted and are still ongoing on the technical feasibility of lacquer + PVD systems. Numerous test results of different lacquer + PVD + lacquer systems on different substrates were provided and assessed for this AfA regarding lacquer + PVD systems. Corrosion resistance: With regard to a three-layer lacquer + PVD + lacquer system, the corrosion resistance is highly dependent on the respective kind of applied PVD intermediate layer. Lacquer + PVD (+lacquer) systems are comparable to a thin ice layer on a less resistant coating layer, which is why such coating systems are highly susceptible to mechanical stress. This means, that if the PVD layer is cracked, the layers beyond do not withstand the impact of corrosive conditions in the environment. In any case, lacquer + PVD (+ lacquer) systems are very prone to corrosion through infiltration of moisture. In a salt spray test according to EN ISO 9227, plastic substrates coated with lacquer were treated for 200 h with a 5% salt solution. After the test the lacquer was peeled of at the edges. This effect is independent from the substrate or a PVD layer and even increased for more sharp-edged substrates (Figure 10).
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ANALYSIS OF ALTERNATIVES
Figure 10: Salt spray test with lacquer coated plastic substrates following EN ISO 9227. Compared to a metallic chrome coating lacquer + PVD systems provide insufficient corrosion performance. Wear / abrasion resistance: In PVD-based coating systems with a final lacquer, the wear resistance of these coatings is clearly lower compared to a metallic chrome coating, as no lacquer is able to fulfil the same abrasion resistance as metallic chrome coatings from chromium trioxide. An abrasion test was conducted with a lacquer + PVD + lacquer brass sample using a Taber linear tester (contact pressure 430 g, 25 strokes per minute). Photos from the sample, which showed surface deficiencies (pores, pits, edge structure) were taken directly after the test and after cleaning of the surface with a soft tissue. After 2,000 cycles scratches on the surface were observed and after 4,000 cycles the damage on the surface increased. After 6,000, 8,000 and 10,000 cycles the damage on the surface decreased which was explained by a polish effect leading to less visible scratches on the surface (Figure 11).
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ANALYSIS OF ALTERNATIVES
Figure 11: Abrasion test with lacquer + PVD + lacquer coated sample after different cycles. Another abrasion test was conducted with a lacquer + PVD + lacquer on ABS sample using a Taber linear tester, a contact pressure of 275 g and 25 cycles per minute. The ABS sample, which showed surface deficiencies (pores, pits, edge structure) from the beginning, was compared after different cycle numbers to a Cr(VI) coated brass reference. The observed abrasion after the test was significantly lower for the Cr(VI) coated brass reference compared to the lacquer + PVD + lacquer coated ABS sample, where the coating was completely removed to the substrate after 1,000 cycles (Figure 12).
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ANALYSIS OF ALTERNATIVES
Figure 12: Abrasion test with lacquer + PVD + lacquer coated ABS sample (top) and Cr(VI) coated brass sample (bottom) after different numbers of cycles (1 = 50 cycles, 2 = 100 cycles, 3 = 200 cycles, 4 = 500 cycles, 5 = 1,000 cycles). Therefore, the abrasion resistance does not fulfil the applicant’s requirements at the current stage of development of PVD-based coatings.
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ANALYSIS OF ALTERNATIVES
Adhesion: No data are available, but with regards to this key functionality, no critical limitations are expected for PVD-based metal coatings. This key functionality will be tested only in case satisfactory results are obtained for the main key functionalities (e.g. corrosion resistance). Chemical resistance: Test results of lacquer + PVD + lacquer coatings were not consistent. Some of the tested coatings were stated to clearly fail the continuous immersion test in household cleaning agents, while other results showed that both continuous immersion tests as well as cleaning agent spray tests with household cleaning agents (such as vinegar essence, disinfection agent Sagrotan, etc.) were passed. In general, the final lacquer defines the functionality of the overall coating and is the reason for the varying test results. No final overall conclusion can be made, but inconsistent performance is clearly not sufficient and processes with consistent and reproducible performance need to be developed. Substrate compatibility: A number of different substrates (metal as well as plastic) can be applied with a lacquer + PVD system, however these kinds of alternative are more focused on plastic substrates. The lacquer + PVD systems can be applied on plastic ABS substrates. Since this is not a galvanic coating, a chemical etching pre-treatment is not necessary. Application of a soft coating (lacquer) on a hard metal substrate followed by a PVD metal coating is considered critical due to different expansion of the layers and therefore the compatibility of this PVD technique with metal substrates is limited. Furthermore, the optical appearance on metal substrates of laquer +PVD (+lacquer) systems is not equivalent to Cr(VI) electroplating. Temperature change resistance / heat resistance: The temperature change resistance of a lacquer + PVD + lacquer coating on ABS was found not to meet the company specific requirements, as the coating was completely milky at the end of the 300-cycle test. In general, the temperature change resistance is dependent on the lacquer + PVD + lacquer coating. In conclusion, the temperature change resistance of PVD based coatings does not meet the requirements at the current stage. Colour consistency: According to product information of one commercially available lacquer + PVD + lacquer system, the system is advertised to provide a bright chrome-like appearance. However, it was stated that the aesthetic and brightness of this system is not as good as a metallic chrome coating applied by chromium trioxide electroplating. Additionally, the colour change over time (colour stability, colour match) was stated to be worse and the metal feeling is missing. Surface appearance: In general, the aesthetic appearance of lacquer + PVD + lacquer systems is highly dependent on the final lacquer and is generally considered to be worse than a metallic chrome coating. With regard to a two-layer lacquer + PVD coating, and considering a PVD chrome layer, the aesthetic is determined to be sufficient, however due to the very thin PVD coating there is no metal feeling. Ni leaching: Not relevant as no nickel is part of any coating layer. Sunlight resistance: No data are available, but with regards to this key functionality, no critical limitations are expected for PVD-based metal coatings. This key functionality will be tested only in case satisfactory results are obtained for the main key functionalities (e.g. corrosion resistance). Process conditions: PVD coatings, which are directly applied on the substrate, require an atomically clean surface because they are highly sensitive to contaminants (e.g. water, oils and paints) on the
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ANALYSIS OF ALTERNATIVES surface to be coated. Inadequate or non-uniform ion bombardment leads to weak and porous coatings and is the most common failure in PVD coating (Legg, 2003). In most cases, ion bombardment during coating is responsible for a high internal stress. This stress accelerates with increasing coating thickness and can lead to delamination of the coating. Therefore, PVD layers are optimally applied with a thickness of about 1-3 µm (in rare cases about 15 µm). The implementation of the PVD technology requires an adaption of the production parameters for each single part to be coated keeping in mind that there are more influencing variables for PVD coatings than for coatings with chromium trioxide. Thus, the adaption of the PVD process for more than xxxxxxxxxxxxxxx typically coated at the applicant would result in significant time and cost efforts. In other industry sectors, PVD machines can be designed and optimised for one specific part, which subsequently allows coating of high volumes of this specific part. However, this is not possible in the sanitary industry where significantly larger amounts of different parts often in low quantities are produced. Conclusion: Lacquer + PVD + lacquer systems are currently no technically feasible alternatives to metallic chrome coatings from chromium trioxide electroplating. While the performance of the coatings regarding corrosion resistance and chemical resistance is highly dependent on the respective coating system and the applied PVD metal, the abrasion resistance, temperature change resistance and colour consistency of the systems do not sufficiently fulfil the requirements.
Wear resistance Temp. change Corrosion Chemical Substrate / abrasion Adhesion resistance / heat resistance resistance compatibility resistance resistance depending on depending on
deposited metal substrate
Colour Surface Prevention of Sunlight Process consistency appearance nickel leaching resistance conditions depending on
deposited metal
6.2.3.3 Economic feasibility Investment costs: In all cases, very high investments for setting up PVD based production lines at an adequate size to guarantee the sufficient throughput of parts are necessary. The costs for a production line depends on the required size of the coating chamber. In case of transition from chromium trioxide electroplating to a PVD based alternative, the installation of completely new production lines is required, as the PVD based process cannot be operated in the same installations. In addition, technical knowledge of the operating staff is required. The number of PVD machines needed to replace Cr(VI) based electroplating depends on the capacity of available machines. The applicant estimated the number of required PVD machines necessary to cover the current plating capacity by using publically available information and estimating how many typical sanitary parts with complex geometries per run would fit in a batch machine from an established PVD supplier (a continuous process is not suitable for the spectrum of parts). A very conservative estimation led to the conclusion that at least xxxxxxxxxxxxxx (24 h operation per day) would be necessary. Assuming the minimal amount of EUR 2 million for one PVD machine including
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ANALYSIS OF ALTERNATIVES painting line and using the very conservative estimation of xxxxxxxxxxx, xxxxxxxxxxxxxxxx have to be invested by the applicant in order to guarantee the current plating capacity. Importantly, the PVD technology of the supplier is developed to coat plastic substrates, which can be heated (prerequisite of PVD process) significantly easier than massive metal substrates. In addition to investment costs, the vacuum chamber must have a sufficient size for the respective parts (for example kitchen fittings, shower fittings and accommodate the complexity of the parts. In general, the need of a vacuum chamber limits the size and the type of parts that can be coated. PVD, a line-of-sight process, is not suitable for complex geometries and large parts. The complexity and size of the parts to be coated with PVD must be considered when planning the vacuum based process. Provided information by PVD suppliers regarding coating capacities per machine are usually related to idealised dimensions of parts to be coated and therefore do not consider complex geometries and large parts. In reality, an ideal placement of parts in the PVD machines is not possible. Further investment is required, because the now used technology for the application of the branding to the products (laser) is not compatible with lacquer and would therefore have to be replaced by screen-printing installations. Operational costs: Indications were made stating that the operational costs for lacquer + PVD systems are up to 400% higher compared to electroplating using chromium trioxide. Further factors are that the coating costs for PVD metal are significantly higher, because no wet-in-wet coating is possible, and at the current stage full automation is not possible. Additionally, far more time is required to coat the same amount of parts with this method compared to galvanic chrome coating, which also leads to higher costs per coated part. Additionally, due to the complexity of PVD based systems, maintenance is very high.
6.2.3.4 Reduction of overall risk due to transition to the alternative As the alternative is not technically feasible, only classification and labelling information of substances and products were reviewed for comparison of the hazard profile. Based on the available information on the substances used within this alternative (see Appendix 1.1.2), titanium nitride would be the worst case with a classification as Flam. Sol. 2, Skin Irrit. 2 and Eye Irrit. 2. As such, transition from chromium trioxide - which is a non-threshold carcinogen - to this substance would constitute a shift to less hazardous substances. Drinking water compliance: In case of an UV lacquer used for the lacquer + PVD coating system, it is considered that – based on the technical application procedure - UV lacquers are not limited to the outside of the product to be coated, but may also be diffused to the inner geometry (inner waterways). Therefore, and due to the necessary curing of the UV lacquers, residues of non-cured particles can remain in inner geometries. UV-lacquers as used for PVD coatings contain photosensitive radical formers. As soon as exposed to light, a chain reaction which leads to the formation of polymers, is induced. In this context the radicals can attack other lacquer constituents as well as human tissue, where they can cause serious damage even leading to the formation of cancer through uncontrolled cell proliferation. Some of the substances known in the application in UV-lacquers are even rated as SVHC. Furthermore, there is a risk that UV radiation does not harden the entire resin due to incomplete penetration. Components of unhardened resins are toxic and can get to the end-consumer
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ANALYSIS OF ALTERNATIVES and into the environment. For these substances an approval for materials in contact with drinking water is not likely to be granted. Therefore, using these UV lacquers will either not be possible, or highly technical design is required, or expensive process technology would be required to prevent the migration of UV-lacquer residuals to the inner waterways. For any substance not on the positive list of the drinking water directive, an approval for materials in contact with drinking water must be achieved, for which extensive testing and risk assessment are required. Considerable time is required for such a process as the methods often have to be developed first. An approval is not if the risk assessment reveals the unsuitability of a substance for a coating with drinking water contact. Therefore, switching from Cr(VI) electroplating to lacquer + PVD systems does not necessarily constitute a shift to less hazardous substances. Consequently, it is not likely that a lacquer + PVD alternative with UV lacquers can be used for materials in contact with drinking water.
6.2.3.5 Availability As reported in course of CTAC, a long-term R&D project on the technical feasibility and development of lacquer + PVD + lacquer coatings was performed by a company within the sanitary sector. The project conducted more than 25 test trials and it was shown that lacquer + PVD + lacquer is a partly technically feasible alternative to metallic chrome coatings from chromium trioxide as electrolyte on a small pilot scale. The existing technical issues on converting the process to large-scaling and e.g. aesthetics, corrosion resistance, chemical resistance and abrasion resistance, have to be further investigated by a prototype plant. Due to the high investment costs for this, further development is halted at the moment. The possibility of using the current lacquer coatings for applications in contact with drinking water has not yet been evaluated and may not be solved at all. If the lacquer is not permitted by the authorities, in cured or uncured condition, for parts in contact with drinking water, highly technical designs, or cost expensive process technology would be needed to cover the entire inner waterways against coating. It is estimated that no sufficient capacities are available on the market for the broad application of lacquer + PVD + lacquer systems (with either applying a chrome or aluminium coating). The transition to this alternative would demand the set-up of new production lines across the market, which would result in high investments costs when at the same time the use of a lacquer + PVD + lacquer coating is limited to simple parts with small geometries. Further technological development of PVD based processes, and especially of the lacquer + PVD + lacquer systems, is necessary before a coating system may become technically comparable to metallic chrome coatings applied using chromium trioxide.
6.2.3.6 Conclusion on suitability and availability of lacquer + PVD systems At the current stage of development, lacquer + PVD systems are not a technically feasible alternative to chromium trioxide electroplating. At the current stage, coatings from lacquer + PVD systems do not sufficiently fulfil the applicant’s critical requirements, especially regarding corrosion resistance, wear resistance / abrasion resistance, chemical resistance, temperature change / heat resistance, colour consistency and process conditions.
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Therefore, large technical efforts are necessary for the development of a coating or a coating system that is potentially able to meet the overall requirements of the sanitary sector. To conclude, due to the insufficient technical performance, very high investment and production costs and uncertainties regarding availability of PVD machines and applicability to the broad product spectrum in the sanitary sector (different sizes and geometries) the lacquer + PVD technology cannot be considered as suitable alternative to chromium trioxide based electroplating. Finally, it is questionable whether authority approval for drinking water contact is achievable with lacquer + PVD systems. In any case intensive testing and risk assessment is required before an approval is granted.
6.3 Outlook on substitution From a technical perspective, there are clear aspects that show that a review period of at least 12 years is needed until substitution of chromium trioxide in plating of sanitary goods can be achieved. • Any potential alternative must sufficiently fulfil every key functionality to achieve a high- quality surface under the conditions of use. Therefore, the potential of each alternative and the accompanied risk regarding technical performance, market implementation and regulatory compliance is being evaluated carefully (at least two years). • The process has to be developed in-house in close collaboration with the alternative supplier. This step includes initial tests and process adjustments depending on results of the sample parts. Importantly, the applicant is only user of the alternative and strongly relies on input from the supplier (at least 4 years). • The sanitary sector comprises a very time-consuming development and implementation process both from a technical and regulatory point of view. Long-term tests have to be developed for all parts, e.g. with respect to nickel leaching (drinking water directive) or new materials in contact with drinking water. “Real-life” tests in a small series at single customer level are performed in order to evaluate the performance of products under typical conditions of use and identify significant technical limitations. Depending on obtained results, the process is adapted and re-testing is performed until sufficient performance to meet the requirements of the sanitary sector is obtained (2 – 4 years). • Technical modification of the production site can be initiated gradually as soon as the process is under control and the coatings are accepted by customers. Besides the actual reconstruction measures of the production site this step may comprise approval procedures (permission) for the reconstruction of the production building, identification and development of suitable land and authority permission for the process start (4 – 6 years). • After modification of the production site market introduction of newly developed and produced parts takes place and the production capacity can be increased. Further upscaling of the process depending on market needs is possible (at least 2 years). Phasing out of Cr(VI) is expected to take at least 2 years. Aspects, such as sales contracts and spare part obligations have to be considered. With over xxxxxxxxxxxxxx coated by the
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applicant, it is obvious that, if an alternative is found, the phase out of Cr(VI) is a lengthy process keeping in mind that it is directly dependent on the acceptance of clients.
Figure 13: Review period applied for.
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7 CONCLUSIONS
7.1 Overall conclusion on suitability and availability of possible alternatives For sanitary applications, electroplating is used to achieve a high-quality surface with excellent durability in contact with aggressive and demanding environmental conditions and at the same time has a high aesthetic and decorative value. The finishes have a bright or matt silvery appearance. The metallic chrome layer is applied as final coating on top of a multi-layer system and the combination of underplates is responsible for the final appearance (bright or matt) of the top coating as well as for the even surface. The underplates vary depending on the different required functionalities of the final product and the used substrate. The chromium trioxide based electroplating is a complex process typically involving numerous steps, such as underplating steps and the main electroplating process. During material specification compatibility and technical performance of the overall system are therefore of upmost importance. The most promising alternatives to electroplating of different substrates using chromium trioxide for sanitary applications are trivalent chromium electroplating and PVD-based processes, for which intensive R&D has been performed for many years and is still ongoing. In recent years, technical improvements have been achieved particularly for Cr(III), which is for many reasons the most promising and favoured potential alternative for the applicant. However, the identified alternatives are technically (and economically) not yet feasible and can therefore not be considered suitable to replace chromium trioxide at the current stage of development. Specifically, coatings based on trivalent chromium do not provide sufficient corrosion resistance and colour consistency (both directly after production and when exposed to light for a certain time). With respect to PVD based processes, the technical feasibility is not comparable to coatings obtained from chromium trioxide based electroplating. In addition, transition to PVD based processes would lead to very high investment costs and the coating time is usually significantly higher resulting in increased costs per part and thus a reduced competitiveness. To conclude, no chromium trioxide free process that provides all required key functionalities for applications in the sanitary sector is available.
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7.2 Information on the review period applied for Comparing the detailed information provided in this document, against the publication made by ECHA on “Setting the review period when RAC and SEAC give opinions on an application for authorisation”2, the following conclusions are drawn by the applicant on the length of the review period: From a technical and economic perspective, there are clear aspects that show that a long review period of at least 12 years is needed until substitution of chromium trioxide in plating of sanitary goods can be achieved. • The continued availability of Cr(VI) plated imports, independent of the length of the review period or in case no authorisation is granted, suggests that any alternative would have to reveal at least the same performance and price characteristics as Cr(VI) plated parts. Thus, return on investment can only be achieved if the implementation of a new technology is accepted by clients from a technical and economic point of view; • Any potential alternative is required to pass an intensive test program, certification and implementation to comply with demanding requirements from the applicant and its customers; • For many years the applicant has invested efforts in R&D to identify a suitable alternative with comparable performance. Based on the current state of research, implementation of an alternative for chromium trioxide based sanitary applications is expected to take at least 12 years; • With over xxxxxxxxxxxxxxxx coated by the applicant, it is obvious that, if an alternative is found, the phase out of Cr(VI) is a lengthy process keeping in mind that it is directly dependent on the acceptance of clients; • The socio-economic impacts for the non-use scenario as calculated in the SEA outweighs potential health impacts correlated with continued use of chromium trioxide for electroplating in the sanitary sector at least by a factor of 1 : 1,657. Taking into account the worst-case exposure levels provided in the CSR and the resulting worst-case health impacts of EUR 117,053 expected per site until 2030, a long review period that allows step-wise implementation of upcoming alternatives should be granted. As a consequence, a review period of not less than 12 years is selected because it coincides with the best case estimates by the applicant of the schedule required to industrialise alternatives to chromium trioxide for sanitary applications.
2 https://echa.europa.eu/documents/10162/13580/seac_rac_review_period_authorisation_en.pdf
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7.3 Substitution effort taken by the applicant if an authorisation is granted As described in detail Chapter 5, the applicant conducted extensive R&D over the last years including alternative chemicals used in a comparable galvanic processes (trivalent chromium instead of hexavalent chromium) and a completely different technology not related to electroplating (PVD). None of these activities was deemed to be successful, meaning that so far no alternative technology could be identified that meets the essential combination of requirements as described in Chapter 3.3. The applicant is closely collaborating with other companies of the sanitary sector as well as suppliers of potential alternatives in order to solve existing technical limitations and further improve the tested coatings. Importantly, any potential alternative is required to pass an intensive test program, certification particularly related to the drinking water directive and implementation/industrialisation to comply with the high quality requirements from the applicant and its customers. Trivalent chromium electroplating is the most promising and favoured alternative for sanitary applications as it is a similar galvanic process and has the potential of comparable performance. Therefore, the main focus of future R&D efforts by the applicant will be placed on this alternative in order to replace chromium trioxide for functional chrome plating for its applications. Generally, only gradual introduction of an alternative is a practicable way due to the following reasons: • The performance of an alternative must be observed over a long term to ensure that the high quality demands can be met; • Long-term tests e.g. with respect to the drinking water directive, have to be developed and certification for conformity with the drinking water directive will only be provided on a step- by-step basis; • Existing plating lines can only be replaced gradually as a stop of the current production is economically not feasible; • Gradual market introduction of parts produced with an alternative as acceptance by customers cannot be guaranteed and; • Sanitary products typically have a production development time of >7 years and planning/design starts years before parts are produced; • Cr(VI) based electroplating can only be phased out gradually due to sales contracts stipulating a certain period of guaranteed delivery and spare part obligations (spare parts have to be available for around 10 years after production of a product has stopped). All in all, despite of significant effort carried out in the development of technologies replacing chromium trioxide for electroplating purposes, the R&D activities conducted by the applicant throughout the last years showed that an alternative that fulfils the demanding requirements of the sanitary sector is not available. Consequently, the estimated best-case review period is at least 12 years until chromium trioxide based electroplating could be fully replaced by an alternative.
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8 REFERENCE LIST ASTM B571-97 (2013): Standard Practice for Qualitative Adhesion Testing of Metallic Coatings. BedGgstV: German Consumer Goods Ordinance (1992): Bedarfsgegenständeverordnung, as of June 24, 2013. DIN 50018 (2012): Testing in a saturated atmosphere in the presence of sulphur dioxide. DIN 53100 (2007): Metallic coatings - Electroplated coatings of nickel plus chromium and of copper plus nickel plus chromium on plastics materials. DIN 50930-10 (2013): Corrosion of metals - Corrosion of metallic materials under corrosion load by water inside of tubes, tanks and apparatus, part 6, Evaluation process and requirements regarding the hygienic suitability in contact with drinking water. DVGW worksheet W 543 (2007): Druckfeste flexible Schlauchleitungen, Anforderungen und Prüfungen. EN 248 (2003): General specification for electrodeposited coatings of Ni-Cr. EN ISO 9227 (2012): Corrosion tests in artificial atmospheres – Salt spray tests. EN 1811 (2012): Nickel release test - Reference test method for release of nickel from all post assemblies which are inserted into pierced parts of the human body and articles intended to come into direct and prolonged contact with the skin. EN ISO 2409 (2013): Paints and varnishes - Cross-cut test. German Drinking Water Ordinance (2001): Trinkwasserverordnung - Verordnung über die Qualität von Wasser für den menschlichen Gebrauch, as of August 07, 2013. Legg, K (2003): Chrome Replacements for Internals and Small Parts. NEWMOA (2003): Pollution prevention technology profile – Trivalent chromium replacements for hexavalent chromium plating, Northeast Waste Management Officials’ Association. TURI - Toxics Use Reduction Institute (2006): Five chemicals alternative assessment study, University of Massachusetts Lowell. VDS (2017): Vereinigung Deutsche Sanitärwirtschaft e.V. Markt und Branche. [Online] VDS, March 14 2017. [Cited: 12 March 2018.] http://www.sanitaerwirtschaft.de/de/marktforschung/badgeschaeft_floriert-406.aspx
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9 APPENDIX 1: INFORMATION ON RELEVANT SUBSTANCES FOR IDENTIFIED ALTERNATIVES APPENDIX 1.1: Electroplating alternatives (main process) APPENDIX 1.1.1: ALTERNATIVE 1: Trivalent chromium electroplating
Table 1: Substance ID and physicochemical properties. Physicochemical Parameter Value Value properties Chemical name and Chromium(III) Physical state at 20°C Solid [1] composition sulphate and 101.3 kPa EC number 233-253-2 Melting point 90 °C [1]
CAS number 10101-53-8 Density 3.10 g/cm³ (anhydrous) [1] Chromium(III) IUPAC name Vapour pressure - sulphate Insoluble in water and acids Molecular formula Cr2(SO4)3 Water solubility (anhydrous). Soluble as hydrate [2] Flammability Non-flammable Molecular weight 392.18 g/mol Flash Point - Physicochemical Parameter Value Value properties Chemical name and Chromium(III) Physical state at 20°C solid composition chloride and 101.3 kPa EC number 233-038-3 Melting point ca. 1150 °C
CAS number 10025-73-7 Density 2.87 g/cm³ (25 °C) Chromium(III) IUPAC name Vapour pressure - chloride
Molecular formula CrCl3 Water solubility 0.585 g/cm³ Flammability Non-flammable Molecular weight 158.36 g/mol Flash Point - Physicochemical Parameter Value Value properties Chemical name and Chromium trichloride Physical state at 20°C Solid (green) composition hexahydrate and 101.3 kPa Melting/freezing point EC number n.a. 80-83°C [²] CAS number 10060-12-5 Density - Chromium(III) - IUPAC name Vapour pressure chloride hexahydrate
Molecular formula CrCl3 · 6H2O Water solubility 590 g/L (at 20°C) Non flammable Flammability Molecular weight 266.45 g/mol - Flash point
Chemical name and Boric acid (mono Physical state at 20°C Solid (crystalline, odourless) composition constituent substance) and 101.3 kPa
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Physicochemical Parameter Value Value properties No melting point detected below EC number 233-139-2 Melting/freezing point 1000°C CAS number 10043-35-3 Density 1.49 g/cm3
IUPAC name Boric acid Vapour pressure 9.90 . 10-8 kPa (25 °C)
Molecular formula BH3O3 Water solubility 48.40 g/L (20°C, pH = 3.6)
Molecular weight 61.83 g/mol Flammability Non flammable Physicochemical Parameter Value Value properties Chemical name and Physical state at 20°C Ammonium chloride Solid (crystalline) composition and 101.3 kPa EC number 235-186-4 Melting/freezing point 340°C (sublimation)
CAS number 12125-02-9 Density 1.53 g/cm3 (at 20°C)
IUPAC name Ammonium chloride Vapour pressure -
Molecular formula ClH4N Water solubility 283 g/L (25°C) Flammability Non flammable Molecular weight 53.5 g/mol Flash Point -
Table 2: Hazard classification and labelling.
Hazard Hazard Statement Number Additional Class and Regulatory and Substance Name Code(s) of classification and Category CLP status Notifiers labelling comments Code(s) (labelling) Currently not Chromium REACH registered; sulphate 1,103 notifiers did Not Not included in the (CAS 10101- - 1,103 not classify the classified CLP Regulation, substance. 53-8) Annex VI; (EC 233-253-2) Included in C&L inventory H302 (Harmful if Additional 6 parties Acute Tox. 4 Currently not swallowed) notified the substance REACH Chromium H315 (Causes skin as Acute Tox 4 registered; Skin Irrit. 2 (H302) only. chloride irritation) Not included in the 41 (CAS 10025- Further 6 notifiers CLP Regulation, H319 (Causes submitted the 73-7) Annex VI; Eye Irrit. 2 serious eye classification as as Included in C&L (EC 233-038-3) irritation) Acute Tox 4 (H302) inventory H330 (Fatal if and Aquatic Chronic Acute Tox. 1 inhaled) 3 (H412).
Chromium Skin Irrit. 2 H 315 (causes skin REACH trichloride irritation) registered; hexahydrate Eye Irrit. 2 H 319 (causes 30 Not included in the (CAS 10060- serious eye CLP Regulation, 12-5) STOT SE 3 irritation) Annex VI;
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Hazard Hazard Statement Number Additional Class and Regulatory and Substance Name Code(s) of classification and Category CLP status Notifiers labelling comments Code(s) (labelling) H 335 (may cause Included in C&L respiratory inventory irritation)
Acute TOX H 302 (harmful if 24 4 swallowed)
Not 5 classified
REACH registered; Included in CLP Regulation, Annex Boric acid H360FD (May VI (index number (CAS 10043- damage fertility. 005-007-00-2); Repr. 1B n/a 35-3) May damage the Included (EC 233-139-2) unborn child) according to Annex XVI on the candidate list (SVHC substance) Harmonised classification- Ammonium H 302 (harmful if Annex VI of chloride swallowed) Regulation (EC) Acute Tox 4 (CAS 12125- H 319 (causes No 1272/2008 Eye Irrit. 2 02-9) serious eye Included in CLP (EC 235-186-4) irritation) Regulation, Annex VI (index number 017-014-00-8);
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APPENDIX 1.1.2: ALTERNATIVE 2: PVD based processes - Lacquer + PVD + Lacquer and PVD metal
Table 1: Substance ID and physicochemical properties. Physicochemical Parameter Value Value properties Chemical name and Titanium nitride (mono Physical state at 20°C Solid (gold) composition constituent substance) and 101.3 kPa EC number 247-117-5 Melting/freezing point 2930°C
CAS number 25583-20-4 Density 5.22 g/cm3
IUPAC name Titanium nitride Vapour pressure -
Molecular formula TiN Water solubility Insoluble in Water Flammability Non flammable Molecular weight 61.87 g/mol Flash Point: - Physicochemical Parameter Value Value properties Chemical name and Physical state at 20°C Chromium nitride Solid (dark powder, odourless) composition and 101.3 kPa EC number 246-016-3 Melting/freezing point -
CAS number 24094-93-7 Density 5.90 g/cm³
IUPAC name [4] Azanylidylnechromium Vapour pressure -
Molecular formula CrN Water solubility Insoluble Flammability - Molecular weight 66.0 g/mol Flash Point: - Physicochemical Parameter Value Value properties Chemical name and Physical state at 20°C Titanium carbonitride powder composition and 101.3 kPa EC number 603-147-4 Melting/freezing point > 350°C
CAS number 12654-86-3 Density 5.08 g/ cm3 (at 25°C)
IUPAC name Titanium carbonitride Vapour pressure n.a
Molecular formula CNTi2 Water solubility n.a Flammability n.a Molecular weight 121.75 g/mol Flash Point: n.a
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Table 2: Hazard classification and labelling.
Substance Name Hazard Hazard Statement Code(s) Number Additional Regulatory and Class and (labelling) of classification CLP status Category Notifiers and labelling Code(s) comments Titanium nitride Not 11 Notified (CAS 25583- classified Classification 20-4 ) Flam. Sol. H 228 (flammable solide) 10 (EC 247-117-5) 2 H 315 (causes skin irritation) Skin Irrit. H 319 (causes serious eye 2 irritation) Eye Irrit. 2 Titanium Not According to carbo nitride classified suppliers MSDS this substance is (CAS 12654- not classified 86-3) according to EG (EC 603-147-4) Nr. 1271/2008. Chromium Not 3 Notified nitride classified Classification (CAS 24094- 93-7) (EC 246-016-3)
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10 APPENDIX 2: SOURCES OF INFORMATION Information on substance identities, physicochemical properties, hazard classification and labelling are based on online data searches. All online sources were accessed between June and September 2014. The main sources are: Source: - European Chemicals Agency: http://echa.europa.eu/de/ - ChemSpider http://www.chemspider.com - http://www.chemicalbook.com - http://pubchem.ncbi.nlm.nih.gov - http://www.scbt.com - Merck Safety Data Sheet: http://www.merck-performance-materials.com/ - Sigma Aldrich Safety Data Sheet: http://www.sigmaaldrich.com/ - http://www.sciencelab.com/msds.php?msdsId=9927079 - Alfa Aesar Safety Data Sheet: http://www.alfa.com/ - United States Environmental Protection Agency internet site: http://www.epa.gov - Carlroth Safety Data Sheet: http://www.carlroth.com/ - Fisher Scientific Safety Data Sheet: http://www.fishersci.com - Carl Roth Safety Data Sheet: http://www.carlroth.com/media - www.nyltek.com/pdf/SAFETY.pdf
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