ANALYSIS OF ALTERNATIVES Legal name of applicants: Henkel AG & Co. KGaA; Henkel Global Supply Chain B.V. Submitted by: Henkel AG & Co. KGaA. Substance: Dichromium tris(chromate), EC No: 246-356-2, CAS No: 24613-89-6 Use title: Use of Dichromium tris(chromate) for surface treatment of metals such as aluminium, steel, zinc, magnesium, titanium, alloys, composites, sealings of anodic films Use number: 2 Use number: 2 Copy right protected - Property of Members of the CCST Consortium - No copying / use allowed. 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. ii Use number: 2 Copy right protected - Property of Members of the CCST Consortium - No copying / use allowed. ANALYSIS OF ALTERNATIVES CONTENTS DECLARATION .......................................................................................................................................................... XV 1. SUMMARY 1 2. INTRODUCTION .................................................................................................................................................. 8 2.1. Substances ........................................................................................................................................ 8 2.2. Uses of Cr(VI) containing substances .............................................................................................. 8 2.3. Purpose and benefits of dichromium tris(chromate) ......................................................................... 8 3. ANALYSIS OF SUBSTANCE FUNCTION.......................................................................................................... 10 3.1. Usage ................................................................................................................................................ 10 3.2. Surface treatment process descriptions ............................................................................................. 15 3.2.1 Pre-treatment processes .................................................................................................................... 17 3.2.2 Main surface treatment processes ..................................................................................................... 18 3.2.2.1 Chemical conversion coating (including phosphate conversion coating: phosphating) ................... 18 3.2.3 Post-treatment processes ................................................................................................................... 19 3.2.3.1 Sealing after (Cr(VI)-free) anodizing ............................................................................................... 19 3.2.3.2 Passivation of metallic coatings........................................................................................................ 20 3.2.3.3 Chromate rinsing (after phosphating) ............................................................................................... 20 3.3. Substance specific characteristics of chromates ............................................................................... 20 3.3.1. Characteristics and properties of dichromium tris(chromate) ........................................................... 21 3.4. Key functionalities of dichromium tris(chromate)-based surface treatments ................................... 21 3.4.1. Key chromate functionalities for the main- and post-treatment process ........................................... 21 3.4.1.1 Corrosion resistance ......................................................................................................................... 22 3.4.1.2 Adhesion promotion (adhesion to subsequent coatings or paint) ..................................................... 22 3.4.1.3 Layer thickness ................................................................................................................................. 22 3.4.1.4 Chemical resistance .......................................................................................................................... 22 3.4.1.5 Resistivity (electrical contact resistance) .......................................................................................... 23 3.4.2. Summary of selected quantified key functionalities ......................................................................... 23 3.4.2.1 Chemical conversion coatings - aluminium ...................................................................................... 25 3.4.2.2 Chemical conversion coatings - magnesium .................................................................................... 25 3.4.2.3 Sealing after (Cr(VI)-free) anodizing ............................................................................................... 25 3.4.2.4 Passivation of metallic coatings........................................................................................................ 26 3.4.2.5 Rinsing after phosphating ................................................................................................................. 26 4. ANNUAL TONNAGE............................................................................................................................................ 27 4.1. Annual tonnage band of Dichromium tris(chromate) ....................................................................... 27 5. OVERVIEW OF THE PROCESS FOR ALTERNATIVE DEVELOPMENT AND APPROVAL IN THE AEROSPAC SECTOR ...................................................................................................................................... 28 5.1. Development and qualification ......................................................................................................... 31 5.1.1. Requirements development .............................................................................................................. 31 5.1.2. Technology development ................................................................................................................. 32 5.1.3. Qualification ..................................................................................................................................... 34 5.1.4. Certification ...................................................................................................................................... 35 5.1.5. Implementation / industrialisation .................................................................................................... 37 5.1.6. Examples .......................................................................................................................................... 38 6. IDENTIFICATION OF POSSIBLE ALTERNATIVES ......................................................................................... 41 6.1 Description of efforts made to identify possible alternatives ........................................................... 41 6.1.1 Research and development in the aerospace sector .......................................................................... 41 6.1.2 Data searches .................................................................................................................................... 42 6.1.3 Consultations .................................................................................................................................... 42 6.2 List of possible alternatives .............................................................................................................. 43 7. SUITABILITY AND AVAILABILITY OF POSSIBLE ALTERNATIVES ......................................................... 44 7.1. Main processes & post treatments .................................................................................................... 44 CATEGORY 1 ALTERNATIVES ............................................................................................................................... 44 7.1.1. ALTERNATIVE 1: Acidic surface treatments ................................................................................. 44 7.1.1.1 Substance ID and properties ............................................................................................................. 44 7.1.1.2 Technical feasibility ......................................................................................................................... 45 Use number: 2 iii Copy right protected - Property of Members of the CCST Consortium - No copying / use allowed. ANALYSIS OF ALTERNATIVES 7.1.1.3 Economic feasibility ......................................................................................................................... 46 7.1.1.4 Reduction of overall risk due to transition to the alternative ............................................................ 46 7.1.1.5 Availability (R&D status, timeline until implementation)................................................................ 46 7.1.1.6 Conclusion on suitability and availability for acidic surface treatments .......................................... 46 7.1.2. ALTERNATIVE 2: Silane/siloxane and sol-gel coatings ................................................................ 46 7.1.2.1 Substance ID and properties ............................................................................................................