Flame Retardants Frequently Asked Questions

The European Flame Retardants Association EFRA - The European Flame Retardants Association

Chemistry making a world of difference

Compiled and edited by Adrian Beard, Clariant, fire test photos by Ralf Baumgarten taken at Siemens Brandversuchshaus in Frankfurt- Hoechst and BayerIndustryServices Fire Test Laboratory in Leverkusen. We thank the teams of Knut Bauer and Michael Halfmann for their help and technical assistance.

Cover photos: Candles are a common cause of ignition for domestic fires. The stereo shown on the front cover is engulfed in flames after 7 minutes when ignited with a small flame - see the photo on the back cover. Contents

Flame Retardants - General Aspects 2

General Fire Safety 4

Fire Safety Standards and Regulations 8

Flame Retardants and other Safety Technologies 12

Flame Retardant types and applications 14

Brominated Flame Retardants (BFRs) 16

Flame Retardants based on Phosphorus Compounds (PFRs) 18

Mineral flame retardants 20

Nitrogen-containing Flame Retardants 22

Other Flame Retardants - Borates, Stannates, ... 24

Flame Retardants - Health and the Environment 26

Recycling and Waste Management of Flame Retardants 32

Common Abbreviations for Flame Retardants 35

Literature and Further Reading 36

EFRA Members 37

1 Flame Retardants Frequently asked Questions

Flame Retardants - General Aspects

What are flame retardants?

Flame retardants are chemicals which are added to combustible materials to render them more resistant to ignition. They are designed to minimise the risk of a fire starting in case of contact with a small heat source such as a cigarette, candle or an electrical fault. If the flame retarded material or an adjacent material has ignited, the flame retardant will slow down combustion and often prevent the fire from spreading to other items. Since the term “flame retardant” describes a function and not a chemical class, there is a wide range of different chemicals which are used for this purpose. Often they are applied in combinations. This variety of products is necessary, because the materials and products which are to be rendered fire safe are very different in nature and composition. For example, plastics have a wide range of mechanical and chemical properties and differ in combustion behaviour. Therefore, they need to be matched to the appropriate flame retardants in order to retain key material functionalities. Flame retardants are thus necessary to ensure the fire safety of a wide range of materials including plastics, foam and fibre insulation materials, foams in furniture, mattresses, wood products, natural and man-made textiles. These materials are e.g. used in parts of electrical equipment, cars, airplanes and building components.

2 tronic equipment where the accel- litres of petrol? Flame retardants erating processor power, electronic can be applied to many different sophistication but at the same time flammable materials to prevent a miniaturisation, result in a concen- fire or to delay its start and propa- tration of energy and an increase in gation by interrupting or hindering risks of local overheating or other the combustion process. They thus electrical fire risks. Flame retardants protect lives, property and the en- can prevent an increase in fire risk vironment. Flame retardants con- from the growing number of con- tribute to meeting high fire safety sumer and electronic goods in hom- requirements for combustible ma- es and offices. Flame retardants terials and finished products pre- protect modern materials such as scribed in regulations and tests. Al- technical plastics, building insula- though fire safety can be achieved tion, circuit boards and cables from by using non-combustible materials igniting and from spreading a fire. in some cases or by design and engineering approaches, the use of Once a fire starts in a room of a flame retarded materials often house, it can develop rapidly, if it meets the functionality and aesthet- spreads to items other than that ic requirements of the consumer as first ignited. Once a number of well as offering the most econom- items are burning, the temperature ical approach. in the room will rise, and may reach "flash over" point, when hot burning gases cause effectively the whole Examples: room to catch light, often violently. Once this occurs, escape from the Metal casings for electrical equip- room is impossible, and spread of ment afford fire safety, but pose the fire to other rooms is very likely. electrical risks, as well as being Flame retardants act both by pre- heavier, more expensive and less venting the initial start of a fire by design flexible than modern plas- impeding ignition and by delaying tics. the spread of the fire, thus increasing escape time, and perhaps pre- An increasing use of plastics in venting "flash over". cars, trains and aeroplanes offers lower weight and so improved fuel economy, but necessitates What are the benefits of flame retar- flame retardants to ensure fire dants? safety.

Most people do not realise that their Mineral fibres for building insul- television set, sofa, mattress and ation are not flammable, but may Why do we need flame retardants? computer are all made essentially not offer the same energy perfor- from plastics (originally made from mance, structural characteristics Both our homes and offices contain crude oil), and without the inclusion or flexibility of application as poly- an increasing potential "fire load" of flame retardants many of these mer foams. of flammable materials because of products can be set alight by just a the development of electrical and short circuit or cigarette and be- Even where non-flammable mate- electronic equipment, and of rising come a burning mass in just a few rials such as steel are used, flame levels of comfort (furniture, carpets, minutes. Did you know for example, retardant intumescent coatings can toys, magazines and papers ...). that a regular TV set contains in its provide valuable heat protection for The potential causes of fires also combustible plastics an energy con- these to limit or delay mechanical tend to increase, especially in elec- tent which is equivalent to several deterioration in the case of fire.

3 Flame Retardants Frequently asked Questions

General Fire Safety

How large is the number of victims from fires?

Statistics show that generally between 10 and 20 fire deaths per 1 000 000 inhabitants are reported in the major industrial countries of the world. The number of severely injured people is estimated at ten times this figure, i.e. 100 to 200 per 1 000 000 inhabitants per year. Every day in Europe there are about 12 fire victims and 120 people severely injured. About 80 % of all fire deaths occur in residential buildings. The people most at risk are the very young and the elderly because they are least able to escape in the event of a fire.

www.flameretardants.eu/pdf/0602/fire_stat0602.pdf and World Fire Statistics www.genevaassociation.org

4 What is the most common cause of death in fires?

The most common cause of death in fires is to be overcome by gas or smoke: In the UK, around 50 % of people die this way, while 25 % of deaths are due to burns and 20 % are attributed to both burns and being overcome by gas or smoke. 5 % of fire deaths cannot be speci- fied. Accidental fires in the home have far higher casualty levels than any other location.

Why are fire gases toxic?

Fires gases are toxic, because in all Besides these volatile gases, some fires toxic products are formed from more complex products are formed the incomplete combustion of or- like polycyclic aromatic hydrocar- ganic materials like plastics, wood, bons (PAHs) or halogenated dioxins textiles and paper. The component and furans (PXDD/F). These pro- which usually dominates the toxicity ducts are formed in much lower of fire effluents is carbon monoxide quantities and are not relevant for (CO), which is responsible for over acute toxic effects but they can have 80 % of all people killed by fire gas- long term health effects. However, es. One striking example is the Düs- because they are higher molecular seldorf Airport fire in 1996: here, all weight substances, they are mostly 17 fire deaths were due to CO poi- adsorbed to soot which reduces soning. By delaying the combustion their toxic potential. The polycyclic of treated materials and the spread aromatic hydrocarbons are typical of the fire, flame retardants signifi- products from incomplete combus- What is the economic damage cantly reduce the emissions of toxic tion of organic materials and they caused by fire? gases. dominate the long-term toxicity of Besides CO, many other toxic com- soot. The conclusion from many The total economic damage is esti- ponents can be formed in a fire: studies carried out on this subject mated at about 25 billion € per year Hydrogen cyanide (HCN) may be is that although the substances in Europe. In Germany alone, com- formed from plastics like polyur- emitted from fires are very variable, pensation costs covered by insur- ethane and polyamide as well as depending on fire conditions, the ance companies amount to 1.5 bil- from natural products which con- toxicity is above all a function of the lion € per year and there are about tain nitrogen like wool and leather. quantity of material burned. 200 major fire incidents with dam- Irritant fire gas components are ages in excess of 0.5 million €. hydrogen chloride (HCl) evolving from plastics like PVC and acrolein www.flameretardants.eu/pdf/ www.gdv.de, www.nfpa.org (USA) released from natural products like babrauskas_summary.pdf wood. However, compared to the toxic potential of CO, which is pre- www.flameretardants.eu/pdf/ sent in large quantities in all fires, prison_mattress.pdf the other fire gas components usu- www.sp.se/fire/Eng/Research/ ally only play a minor role. Fire_LCA_study_TV.pdf

5 Flame Retardants Frequently asked Questions

Does the presence of flame retar- release. The impact of flame retardants increase the toxicity of dants on smoke or fire gases also smoke? depends on the proportion of flame retarded material to the total fire This is a concern which is often load. Room fire tests which com- raised. It is based on the fact that pared a room with non flame retar- some flame retardants act by im- ded materials to a room with flame peding the combustion reactions retarded items (TV cabinet, busi- in the gas phase and therefore lead ness machine housing, upholstered to incomplete combustion which chair, electrical cables, electrical in turn means a smoky fire. circuit board) revealed: However, large scale studies have demonstrated that the toxic hazards The total quantities of toxic gases from a fire are more dependant on released by the FR products was how much is burning under which one third that for the non FR. conditions of temperature and ven- tilation rather than what is burning. Total smoke production was not Two cases can be considered: significantly different.

1.The flame retarded (FR) material "Because the total quantities of is subject to the primary ignition material consumed in the full- source: if this is a small flame or room tests with FR products are other low energy source like a cig- much lower than with non FR pro- arette butt, the presence of flame ducts, the total carbon monoxide retardants in the material may cause [the dominant toxic fire gas] emis- it to smoulder and smoke some- sions are thus around half with what, but will severely impede igni- the flame retarded products, sig- tion and in most cases no fire will nificantly reducing the fire haz- develop. If burning is sustained, the ard." release of heat and the spread of (Source: Babrauskas V. et al. (1988) flames will be severely hindered by Fire Hazard Comparison of Fire-Retar- flame retardants allowing people ded and Non-Fire-Retarded Products. more time to escape from the fire. NBS special publication SP 749. NIST, The most significant reduction in USA) toxic gases from fires is achieved by actually preventing the fire, or Therefore, it is clear that because preventing it from spreading from flame retardants reduce the number one item to a whole room. and extent of fires, they can significantly reduce both the total levels 2.The flame retarded material is of such toxic gases in a given fire not the first item ignited but is invol- and the total emissions from all ved in a fire that is already develop- fires. This has been investigated ing: In this case flame retardants and proven for television sets and cannot prevent the ignition of the upholstered furniture in life cycle material and it will eventually be assessment studies (www.sp.se/fire). thermally degraded or burn. How- Please see the EFRA website for ever, flame retardants will reduce detailed information and references. the rate of flame spread and heat

6 fully developed fire temperature

initiation of fire

time start of fire flash over after < 10 min

How does a fire develop?

A fire can basically be split into three fire. The fire spreads, heats up the oped fire, where temperatures up phases, the initiating fire, the fully surroundings and once the materi- to 1 200 °C can be reached. The fire developed fire and the decreasing als in the room have formed enough will later decrease as the available fire. The fire starts with an ignition flammable gases and are sufficiently fire load is consumed by the fire or source (for example a match) set- hot, flashover takes place and the if the fire occurs in a totally closed ting combustible material (for ex- whole room is engulfed in the fire. room the fire can die because of ample an upholstered armchair) on This is the start of the fully devel- oxygen deficiency.

The fundamental parameters go- paper - on the other hand, there are verning a fire are: materials which are difficult to ignite Heat but once ignited will release a large Combustibility: Will a material amount of energy like diesel fuel or Heat transfer burn? many plastics. In addition, in all fires secondary effects occur. These Ignitability: If it is combustible, do not primarily determine the Heat transfer Fire how and when will it ignite? course of the fire, but cause most of the fire deaths or damage to ma- Spread of flame: Once ignited, terials. These effects are: Fuel Air Mixing of fuel and air how quickly will the flames spread? Smoke development Fire Triangle (according to Emmons) Heat release: What will be the Fire gas toxicity What are the parameters governing rate and total amount of heat a fire? released? Corrosivity and contamination by soot (more relevant to ma- The fire triangle indicates where On the one hand, there are mater- terials than to humans and par- flame retardants can interfere in the ials that are easily ignitable but have ticularly sensitive for electronic combustion process. a relatively small energy content like equipment)

7 Flame Retardants Frequently asked Questions

Fire Safety Standards and Regulations

What is the role of fire safety regulations?

Fire safety regulations aim at preventing fires and saving lives and property. Fire safety regulations exist for building, transportation (road and rail vehicles, aircraft and ships), electrical engineering & electronics as well as for furnishings and textiles. One example for the benefits of fire safety regulations is the introduction of the United Kingdom Furniture and Furnishings (Fire Safety) Regulations in 1988. The strict requirements on the fire performance of upholstered furniture which these regulations stipulated were often met by using flame retardants. Taking into account changes in smoking habits and increased installation of smoke alarms, these regulations were estimated to be saving more than 230 lives and 4 200 injuries per year by 2002 (see graph on opposite page). A study carried out for the French association of Burns Victims (ABF) indicates that a fire safety requirement for furniture would save, in the long term, 210 lives/year and result in net economic benefits of over 700 million €/year

“Preliminary Legal and Socio-Economic Study for the Projected Decree on Fire Safety Standards for Upholstered Furniture”, C. Chevalier for Association des Brûlés de France, July 2005 www.acfse.org/research2.htm

8 total deaths per million population related to smoke from burns from first ignition in upholstery 20 18 16 14 12 10 8 6 4 2 deaths per million population year 0 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 Source: “International Fire Statistics and the Potential Benefits of Fire Counter-Measures”, A. Emsley et al., University of Surrey, UK, 2005. Available at www.cefic-efra.org

What are fire safety requirements? In Europe, the two fields where national requirements are still used, Fire safety requirements are contain- building and railways, are being ed in regulations, technical guide- harmonised in the framework of the lines, safety standards and approval European Union. However in the procedures. Today, they cover field of upholstered furniture, the finished products rather than single national regulations of the UK and materials and allow their classifi- Ireland provide the highest levels cation by the use of specific fire of fire safety. tests. Fire safety requirements are In continental Europe efforts to becoming more and more introduce such strict requirements international: on a European level still continue.

Requirement Examples

General safety EU General Product Safety Construction Products regulations Directive 2001/95/EC Directive 89/106/EC

Product standards IEC 60065 for television sets EN 13162 ... 13171 for and other audio / video thermal insulation products for buildings

Fire test standard UL 94 flammability standard Single Burning Item Test, EN 13823

9 Flame Retardants Frequently asked Questions

What is the role of fire tests?

The role of fire tests is to determine formance is determined. Fire tests requirements defined in the tests. the fire risk of materials and finished were developed to simulate the The sample size can vary from a products used in applications like ignition behaviour of materials or small strip of material (e.g. 12.7 cm building, transportation, electrical even real fire events, which are x 1.27 cm; for the UL 94 test) up to engineering and furniture. They are thought to be particularly harmful boards of 1.5 x 1.5 m2 (SBI-Test), the basis upon which a material's to humans and property. The individual furniture items or even flammability or a product's fire per- products have to meet fire safety complete furnished rooms.

Recent improvements in fire safety standards

In 2006, the United States adopted posed rulemaking for fire safety of Improved standards for furniture a federal regulation requiring strict upholstered furniture and for bed- and mattresses have recently been mattress fire safety for all mattres- clothes. developed: in Sweden, 2002, fire ses sold in the USA from July 2007 requirements for mattresses for (flame resistance and limited heat In Europe, the companies Philips, high risk health institutions and emission). The US Consumer Pro- Panasonic, Finlux and Sony volun- prisons (standard SS 876 00 10); in duct Safety Commission estimates tarily announced in 2004 that all France, 2006, revised fire safety that 240-270 lives and 1 150 - 1 330 their TV sets sold in Europe will in standards for seats in public places injuries per year will be saved, and future be ignition resistant (Article AM 18, Norme NF D calculate a net benefit to society of (www.acfse.org). Unlike generally 60013). US$ 820 million/year. The USA has in Europe, TV sets sold on the US also issued advance notice of pro- market are already ignition resistant.

10 Transportation Are there ways to meet fire safety levels without using flame retar- - Automotive: FMVSS 302 dants? (Federal Motor Vehicle Safety Standard, USA) Yes, there are: safety standards and - Railways: Different national fire tests do not prescribe how to tests and pending new harmo- reach the necessary fire perform- nised European tests ance. For example, a manufacturer (EN TS 45545) can choose a non-combustible ma- - Aircraft: Various Bunsen burner terial like steel for an equipment tests, OSU (Ohio State Univer- housing, or engineering design ap- sity) heat release and kerosene proaches are stipulated in some burner seat tests standards which waive the need for fire proof materials if certain safety distances are kept from potential What are the most important fire Electrical Engineering & ignition sources. Plastic materials tests for the main application areas Electronics are often favoured because of their of flame retardants? low price and ease of processing - Flammability tests according to which allows mass manufacture The most important fire tests for UL (Underwriters Laboratories) even of sophisticated designs and combustible materials used in build- 94: Horizontal burning HB, shapes. The different types of ing, motor vehicles, railways, air- Vertical burning with classes V2, plastics also differ widely in ignita- craft, ships, electrical engineering, V1, V0, 5V bility. However, with the exception furniture, mattresses and textiles - Glow wire test (IEC 60335) of chlorinated polymers like PVC mainly cover the parameters flam- most "naturally" flame resistant mability, spread of flame, heat plastics are also very expensive and release and smoke development. Upholstered furniture and textiles more difficult to process. In textiles Some of the major fire tests are: the situation is similar: inherently - BS 5852: tests for assessment less flammable materials are avail- of the ignitability of upholstered able, but often at a considerably Building seating by smouldering and higher price and usually with differ- flaming ignition sources ent material properties - the "look - National tests: - EN 1021: Cigarette and match and feel" of a fabric is very important tests for furniture filling and if it is used for clothing, furniture French Epiradiateur test cover (part 1 and 2) items or curtains for example. (NF P 92-501 ... 507) - ISO 6940/41: Flammability tests Flame retardants are only one ele- German Brandschacht and for textiles ment of fire safety, however, a very small flame test (DIN 4102) - 16 CFR Part 1633: US federal significant one. Other elements are British Surface spread of flame mattress flammability standard e.g. a good education of the public test (BS 476 part 7) (USA 2006) on fire safety, smoke alarms in public buildings and private homes and - Harmonised European tests: For further information on fire tests a well functioning fire service. Only please refer to: Troitzsch, Jurgen by combining all measures can we Single Burning Item test (2004): Plastics Flammability minimise fire damages and fatali- (SBI, EN 13823) Handbook. Hanser Publishers and ties. Just think of your car - do you Small flame test Oxford University Press, Munich. dispose of the safety belt, now that (EN ISO 11925-2) 3rd edition. you have an airbag?

11 Flame Retardants Frequently asked Questions

Flame Retardants and other Safety Technologies

Is it not sufficient to have smoke alarms in homes?

Do we need chemicals for fire protection, if everybody had a smoke alarm in his home? To answer this question, EFRA commissioned a study at the German Federal Institute for Materials Testing and Research, BAM (www.bam.de), in Berlin. Their task was to evaluate the contributions to fire safety from smoke alarms and flame retarded items in a home, like TV sets or upholstered furniture.

12 tional fluid dynamics (CFD) which In these tests, the fires developed they validated against a number of very rapidly after igniting either a experimental data sets like the NIST. TV or a bed mattress with a candle. study. In these scenarios selected furniture and electrical devices were "From our point of view, a combina- compared with such items with re- tion of both fire safety measures is duced flammability which is typically necessary to fundamentally improve achieved by the application of flame the fire safety in homes: the instal- retardants. Although smoke alarms lation of smoke detectors as well quickly respond to a developing fire as the equipment of high risk items and can alert the inhabitants, espe- of furniture or electrical devices like cially if they are asleep, a clear safety upholstery or TV sets with flame benefit for the scenarios with flame retardants" says Dr. Anja Hofmann, retarded items could be demonstra- lead researcher at BAM. www.rauchmelder-fuer-nrw.de ted: the times to dangerous smoke densities and flashover are significantly reduced which results in For further information see: Previous investigations e.g. of NIST longer escape times. Depending on [1] revealed that smoke detectors the ignition source and the fire safe- www.bam.de/ do have a positive effect on fire ty requirements, a fire might not safety, but they also show that even develop in the flame retarded www.bam.de/de/kompetenzen/ escape times can be very short in case. Numerical predictions are in fachabteilungen/abteilung_7/fg73/ residential fires, even down to less good agreement with the results of index.htm than 4 minutes. This reduction in experimental studies in which flame escape times over the last 30 years retarded furniture or electrical de- 1. Bukowski, R.W., Peacock, R.D., Averill, J.D., is attributed to the widespread use vices were tested in full scale tests. Cleary, T.G., Bryner, N.P., Walton, W.D., Reneke, P.A., Kuligowski, E.D. Performance of of flammable plastics and textiles. In addition, two large scale fire tests Home Smoke Alarms, Analysis of the Response Therefore, the researchers at BAM representing a living room and a od Several Available Technologies in Residential modelled several fire scenarios in children's room were carried out Fire Settings. residential buildings by computa- together with the Berlin fire service. NIST Technical Note 1455, July 2004

13 Flame Retardants Frequently asked Questions

Flame Retardant types and applications

What is the mode of action of flame retardants?

By chemical and/or physical action, flame retardants will inhibit or even suppress the combustion process. They interfere with combustion during a particular stage of this process, e.g. during heating, decomposition, ignition or flame spread. The amount of flame retardant one has to add to achieve the desired level of fire safety can range from less than one percent for highly effective flame retardants up to more than 50 percent for inorganic fillers. Typical ranges are 5 to 20 percent by weight.

The most effective chemical action may take The less effective physical action may take place by place by

Reaction in the gas phase: The radical gas Cooling: Energy absorbing (Endothermic) phase combustion process is interrupted processes triggered by additives and/or the by the flame retardant, resulting in cooling chemical release of water cool the substrate of the system, reducing and eventually sup- to a temperature below that required for pressing the supply of flammable gases. sustaining the combustion process.

Reaction in the solid phase: The flame retar- Formation of a protective layer (coating): dant builds up a char layer and shields the The material is shielded with a solid or gas- material against oxygen and provides a bar- eous protective layer and protected from rier against the heat source (flame). heat and oxygen necessary for the combustion process.

Dilution: Inert substances (fillers) and additives evolving non-combustible gases dilute the fuel in the solid and gaseous phases.

14 2005 EUROPEAN FLAME RETARDANT MARKET CONSUMPTION Data according to EFRA survey and SRI consulting figures, based on tonnages:

Cl-Paraffins 7,4% Brominated FR 10,8%

Melamine 2,8% (and its salts)

Borates 3,2% & Stannates Antimony trioxide 3,4%

MDH 4,3% (magnesium dihydroxide) Chlorinated Phosphates 10,0%

Phosphorus-based, non-halogenated 8,4%

ATH (aluminium trihydroxide) 49,6%

How important is the flame retar- highest market share by volume. dants market? A global growth of around 3 % per year is foreseen for the near future. What are the main families of flame With a global consumption of about Inorganic flame retardants like alu- retardants? 2.9 billion US$, flame retardants minium trihydroxide have experi- are the most important group of enced the highest growth rates late- The main families of flame plastics additives which have a ly, followed by phosphorus and retardants are based on compounds total market volume of around nitrogen based systems. containing: 11 billion €. According to SRI Con- Since a number of flame retardants sulting, the 2005 global flame retar- are high production volume chemi- Halogens (Bromine and Chlorine) dants consumption amounted to cals, they have been scrutinised Phosphorus 1.5 million tonnes. EFRA members under current chemical regulations Nitrogen estimate a consumption of like the European Union risk assess- Intumescent Systems 464 000 tonnes of flame retardants ment process. Minerals (based on aluminium in Europe (EU-25, 2005). and magnesium) Brominated flame retardants have See chapter on Environmental and Others (like Borax, Sb2O3, the highest market share by value Health aspects for further inform- nanocomposites) and aluminium trihydroxide the ation.

15 Flame Retardants Frequently asked Questions

Brominated Flame Retardants (BFRs)

What are the applications of BFRs ?

BFRs are commonly used to prevent fires in electronics and electrical equipment. This area accounts for more than 50% of their applications - for example in the outer housings of TV sets and computer monitors. Indeed, the internal circuitry of such devices can heat up and, over time, collect dust. Short circuits and electrical or electronic malfunctions can occur. Printed circuit boards also require flame retardancy properties which are often provided by a crosslinked brominated epoxy resin polymer manufactured from tetrabromobisphenol-A (TBBPA). In addition, BFRs are used in wire and cable compounds, for example for use in buildings and vehicles as well as other building materials, such as insulation foams. They are also used in speciality fabric back-coatings for curtains, seating and furniture in transport and public buildings as well as domestic upholstered furniture conforming to the UK and Ireland Furniture1 Flammability regulations.

1 Furniture and Furnishings (Fire) (Safety) Regulations 1988, UK

16 pean risk assessment concluded Brominated (poly)styrene that no risk was identified for human health or the environment in the use of Deca-BDE. The two other n commercial products of the PBDE family -PentaBDE and Octa BDE- x = 2,7 may no longer be used in Europe Br since August 2004. x is commonly used in polyester and Hexabromocyclododecane (HBCD) polyamides, It is a polymer itself and is therefore quite immobile in Br Br the matrix.

Brominated phenols

Br Br Br Br

What does a Brominated FR mean? is a cycloaliphatic BFR. It is com-

monly used in foamed polystyrene Brx There are about 75 different com- for insulation of buildings where it mercial BFRs, each with specific is only necessary at very low load- e.g. tribromophenol, are reactive properties and toxicological beha- ings. For compact polystyrene (high flame retardants most often used viour. The only common feature is impact) higher loadings are neces- as intermediates in the manufacture they contain bromine and act in the sary. Another application is in tex- of polymeric brominated flame vapour phase by a radical trap me- tiles. retardants. They can be used as chanism. They come in various end caps in brominated carbonate forms and can be liquids, powders Tetrabromobisphenol-A (TBBPA) oligomers and brominated epoxy or pellets. The most important BFRs Br Br oligomers, which in turn are used are: as flame retardants. HO OH Polybrominated diphenylethers Tetrabromophthalic anhydride (PBDE) Br Br Br O Br Br Br Br Br is mainly used in epoxy resins for printed wiring boards, where it is O Br O Br reacted into the polymer backbone Br and so becomes a tightly bound O Br Br Br Br Br part of the polymer. It is also used as an additive flame retardant is often used as a reactive flame Decabromodiphenylether (Deca- mainly in ABS plastics, as an inter- retardant in unsaturated polyesters BDE) is the only commercial pro- mediate in the production of other used to manufacture circuit boards duct currently in use from the PBDE brominated FR systems, in deriva- and cellular phones. It also serves familly. It has 10 bromine atoms tives, in epoxy oligomers and in as a raw material for the manu- attached to the diphenylether mole- engineering plastics for electrical facture of other flame retardants. cule, a high molecular weight and and electronic devices. The human high thermal stability. Its major health part of the European Risk applications are in styrenic poly- Assessment concluded in May 2005 mers, polyolefins polyesters, nylons that TBBPA is safe for human and textiles. In May 2004, the Euro- health.

17 Flame Retardants Frequently asked Questions

Flame Retardants based on Phosphorus Compounds (PFRs)

What does a phosphorus based flame retardant mean?

The class of Phosphorus-containing flame retardants covers a wide range of inorganic and organic compounds and include both reactive (chemically bound into the material) and additive (integrated into the material by physical misering only) compounds. They have a broad application field, and a good fire safety performance.

The most important phosphorus-containing flame retardants are:

Phosphate esters Phosphonates and phosphinates Red phosphorus and ammonium polyphosphate

18 Phosphates, phosphonates and Ammonium polyphosphate... phosphinates... O are used as reactive phosphorus- containing flame retardants in HO P O H flexible polyurethane foams for automotive and building appli- ONH cations. Additive organic phos- 4 n phinates are a new class of flame retardants for use in engineering grades are primarily used in intu- plastics, particularly in polyamides. mescent coatings. They are also Specific reactive phosphorus flame used in rigid and flexible polyuretha- retardants are used in polyester ne foams and polyolefins (injection fibres (e.g. Trevira CS) and for wash moulded), in formulations for un- resi stent flame retardant textile saturated polyesters, phenolics, finishes. Other reactive organo- epoxies and coatings for textiles. phosphorus compounds can be used in epoxy resins in printed circuit boards.

What are the applications for PFRs?

Phosphorus-containing flame retardants are widely used in standard and engineering plastics, polyurethane foams, thermosets, coatings, and textiles. figure: polymeric structure of red phosphorus

Phosphate esters... Red Phosphorus are mainly used as flame retardant Flame retardant grades based on plasticizers in polyvinylchloride red phosphorus are mainly used in (PVC, alkyl/aryl phosphates) and polyamide 6 and 66, meet UL 94 V0 engineering plastics, particularly in fire safety level at low dosages and polyphenylene oxide/high impact are particularly effective in glass polystyrene (PPO/HIPS), polycarbo- fibre reinforced formulations. nate/acrylonitrile butadiene styrene Further applications are in polyethyl- (PC/ ABS) blends and polycarbo- ene and ethylene vinyl acetate nate (PC, e.g. triphenylphosphate, (EVA), polyurethane foam, and resocinol- and bisphenol A- bis-(di- thermosettings resins (unsaturated phenyl) phosphate). The latter are polyesters and epoxies). widely used in IT housings requiring high fire safety levels. Other appli- Principal chemical structures: cations include phenolic resins and O O O coatings. Additive chlorinated phosphate esters like tris(2-chloroiso- R1 O P O R2 R1 P O R2 R1 P R2 propyl) phosphate (TCPP) and tris(1,3-dichloroisopropyl) phos- O O O phate (TDCP) are used in flexible R R R polyurethane foams for upholstered 3 3 3 furniture and automotive applica- Phosphate Ester Phosphonate Phosphinate tions. TCPP is also widely used in rigid PU insulation foams. R1, R2, R3 are organic substituents, they can be different or the same

19 Flame Retardants Frequently asked Questions

Mineral flame retardants

What does a mineral flame retardant mean?

Aluminium trihydroxide (ATH) is by far the most widely used flame retardant on a tonnage basis. It is inexpensive, but usually requires higher loadings in polymers up to more than 60%, because the flame retardant mechanism is based on the release of water which cools and dilutes the flame zone. Magnesium hydroxide (MDH) is used in polymers which have higher processing temperatures, because it is stable up to temperatures of around 300 C versus ATH which de- composes around 200 °C. Other inorganic fillers like talcum or chalk (calcium carbonate) are not flame retardants in the common sense; however, simply by diluting the combustible polymer they reduce its flammability and fire load.

2 Al(OH) 200 °C 3 H O + Al O 3 + 1050 kJ / kg 2 2 3

Mg(OH) 300 °C H O + MgO 2 + 1300 kJ / kg 2

20 What are the applications for mineral flame retardants?

Fine precipitated ATH and MDH (< 2 µm) are used in melt compounding and extrusion of thermo- plastics like cable PVC or polyolefins for cables. For use in cable, ATH and more often MDH are coated with organic materials to improve their compatibility with the polymer. Coarser ground and air separated grades can be used in liquid resin compounding of thermosets for electrical applications, seats, panels and vehicle parts.

21 Flame Retardants Frequently asked Questions

Nitrogen-containing Flame Retardants

What does a nitrogen flame retardant mean?

Three chemical groups can be distinguished: pure melamine, melamine derivatives, i.e. salts with organic or inorganic acids such as boric acid, cyanuric acid, phosphoric NH2 acid or pyro/poly-phosphoric acid, and melamine homologues such as melam, melem and melon, the latter finding only experimental use at this stage. Nitrogen flame retar- N N dants are believed to act by several mechanisms: In the condensed phase, melamine H N N NH is transformed into cross-linked structures which promote char formation. Ammonia 2 2 is released in these reactions. In conjunction with phosphorus, the nitrogen appears to enhance the attachment of the phosphorus to the polymer. A mechanism in the gas Melamine phase may be the release of molecular nitrogen which dilutes the volatile polymer decomposition products.

22 What are the applications for nitrogen flame retardants?

Melamine is mainly used in polyurethane foams, whereas melamine cyanurate is used in nylons or in polypropylene intumescent formulations in conjunction with ammonium polyphosphate. The phosphate, poly- and pyrophosphates of melamine contain both nitrogen and phosphorus and are used in nylons. In some specific formulations, tria- zines, isocyanurates, urea, guanid- ine and cyanuric acid derivatives are used as reactive compounds.

23 Flame Retardants Frequently asked Questions

Other Flame Retardants - Borates, Stannates, ...

Other Flame Retardants

A number of other substances show flame retarding effects and are used in commercial applications. In this chapter we have compiled information on products which are either synergists, i.e. they enhance the performance of other flame retardants, or which are niche products for special applications, often with a limited market volume.

24 the gas phase and are the result of Expandable graphite... enhancing the radical chain mechanism of the halogens. Antimony is manufactured from flake graphite trioxide is therefore widely used as by treatment with strong acids like a synergist in halogen containing sulphuric or nitric acid. The acid is systems. trapped in the crystal layers of the graphite ("intercalated"). When it is heated, the graphite starts to ex- Zinc compounds... pand up to several hundred cm3 per gram, forming a protective layer were initially developed as smoke for the polymer. Expandable graph- suppressants for PVC (Zinc hydroxy- ite is used in plastics, rubbers (elas- stannate). Later it was found that tomers), coatings, textiles and espe- they also act as flame retardants in cially in polymeric foams. To get certain plastics mainly by promoting perfect flame retardancy, the use of char formation. Zinc sulphide synergists like ammonium poly- shows synergistic effects in PVC phosphate or zinc borate is neces- and can partly substitute antimony sary. The black colour of graphite trioxide. limits its applicability in some cases.

Boron... containing compounds: A major Nanocomposites... application of borates is the use of mixtures of boric acids and borax have been gaining increasing atten- as flame retardants for cellulose tion since the late 1990s as potential (cotton) and of zinc borate for PVC new flame retardants. Nanocom- and other plastics like polyolefins, posites are polymer-layered silicates elastomers, polyamides, or epoxy based on aluminosilicate clay miner- resins. In halogen-containing sys- als like montmorillonite, composed tems, zinc borate is used in con- of layers with gaps (gallery spaces) junction with antimony oxide, while in between. These silicates have the in halogen-free systems, it is norm- ability to incorporate polymers. ally used in conjunction with alu- Flame retardancy work with nano- minium trihydroxide, magnesium Intumescent... composites has focused on plastics hydroxide, or red phosphorus. In like polymethyl-methacrylate some particular applications zinc flame retardant systems expand to (PMMA), polypropylene, polysty- borate can be used alone. Boron produce foams. They are used as rene, and polyamides. Nanocom- containing compounds act by coatings not only to protect composites particularly prevent dripping stepwise release of water and bustible materials such as wood and promote char formation. formation of a glassy coating and plastics, but also steel struc- Therefore, they have been used as protecting the surface. tures in buildings, because steel synergists in some polymer / flame loses its strength when exposed to retardant combinations. However, high temperatures in a fire. The they require special processing and Antimony trioxide... intumescent effect is achieved by for the time being are not consider- combining an acid source like am- ed to become viable stand-alone shows no perceptible flame retar- monium polyphosphate, a source flame retardants. dant action on its own. Together of carbon, compounds which re- with halogen containing com- lease non-combustible gases for pounds like BFRs or PVC it pro- blowing the foam on thermal de- duces a synergistic effect. The most composition and resin binders to important reactions take place in stabilise the foam.

25 Flame Retardants Frequently asked Questions

Flame Retardants - Health and the Environment

What are the concerns against using flame retardants?

The main concerns voiced against flame retardants are that they may persist in the environment, accumulate in living organisms and be detrimental to human health or toxic to wildlife. In addition, there are concerns about potential decomposition products in case of fire.

26 furniture and TV sets, and on emis- assessment on a substance which sions of flame retardants from fur- looks at human health as well as niture. Please consult the EFRA web- environmental effects. Industry pro- site (www.flameretardants.eu) for vides data on substance properties detailed information on EFRA and measurements of the sub- projects. stance at the workplace or in the environment. Often, specific studies are commissioned to fill data gaps What is the difference between haz- for a risk assessment. ard, exposure and risk? In the first step the rapporteur looks at the toxicological and ecotoxico- Hazard expresses the dangerous logical properties of a substance to property of a substance like corros- determine a safe threshold exposure ive, flammable or having a certain dose. This is then compared to the toxicity (e.g. a mean lethal dose of concentrations which are found in 200 mg per kg body weight for rats). the environment or to which hu- Exposure describes the amount or mans are exposed, either real meas- concentration of a substance that urements or estimates. The risk is a human or other organism comes derived both from hazard and expo- into contact with. Only if the level sure. If the exposure is higher than of exposure exceeds the safety level the safety level of a substance of the hazard of the substance, you (determined in laboratory tests) may expect negative effects, i.e. then a risk is identified. This risk is there is a significant risk. This in then subsequently managed by the turn means that you can either authorities and companies involved. choose less hazardous substances or reduce the emissions of chemi- The following table provides an cals from production and proces- overview of the flame retardants sing sites or from finished articles covered in risk assessments.

in order to reduce a potential risk. Substance Abbreviation For example, a lion is a very danger- Antimony trioxide ATO ous animal (when hungry), but if it Short-chain Chlorinated Paraffins SCCP is in a cage, then there is no risk (if Medium-chain Chlorinated Paraffins MCCP How do we deal with these con- you are outside). Pentabromodiphenyl ether PBDE Octabromodiphenyl ether OBDE cerns? Decabromodiphenyl ether DBDE Hexabromocyclododecane HBCD Today, flame retardants are evalua- What is the status of the EU risk Tris(2-chloroethyl) phosphate TCEP Tetrabromobisphenol A TBBPA ted individually in scientific risk as- assessments on flame retardants? Tris(2-chloroisopropyl) phosphate TCPP sessments. This factual approach Tris(1,3-dichloroisopropyl)phosphate TDCPP takes into account the different phy- Risk assessments are carried out 2,2-bis(chloromethyl)trimethylene V6 bis(bis(2-chloroethyl)phosphate) sical, chemical and toxicological in the European Union as part of properties as well as the environ- the regulations on "existing" sub- The current state of risk assess- mental fate and exposure of each stances, i.e. chemicals which were ments as well as published reports individual flame retardant. EFRA on the market in the European Un- are available at: ecb.jrc.it/existing- actively participates in these scien- ion before September 1981. Priority chemicals . You find a summary for tific risk assessments and also lists of high production volume the flame retardants concerned on sponsors or co-operates in a num- chemicals (> 1 000 tons per year) the EFRA website www.flameretar- ber of independent studies to ad- are defined by the authorities. One dants.eu. With the introduction of dress general issues, e.g. on life or two member states then act as REACH (see below), the system of cycle assessments of flame retarded "rapporteurs" and compile a risk official risk assessments will cease.

27 Flame Retardants Frequently asked Questions

under REACH. This risks draining a very low toxicity or impact on manufacturing jobs out of Europe human health or the environment. and nullifying the consumer pro- Others have a certain toxicity as a tection which REACH is intended neat compound, but once they react to ensure. into a polymer the effect is no longer there. The major flame retardants have been in use for many years REACH Are flame retardants toxic? now and toxic effects would have shown up at the workplace in pro- Actually, that question is put wrong- duction or processing, because Flame retardants and REACH ly - it should be "how toxic are flame there the exposure is generally high- retardants?", because only the dose est. Only very few flame retardants The new EU legislation on chemi- determines if a substance has a were withdrawn from the market, cals, REACH, currently under debate toxic effect or not. The potential phased out or regulated because of (2006) will be applicable to flame toxic effects of FRs are low because suspected or proven toxic proper- retardants exactly as to all other they are, in most applications, either ties, often in combination with very chemicals sold or used in the Euro- chemically reacted into the material high margins of safety and the pre- pean Union. All chemicals used in they are used to treat, or physically cautionary principle. significant quantities in Europe will contained within it and so not able have to be registered and subject to have significant external effects. to evaluation and/or authorisation Furthermore, flame retardants are Are any flame retardants banned in procedures, according to their by no means of particular toxicity the European Union? properties, involving both chemical compared to other commonly used suppliers and user industries. chemicals. Since there are so many The Directive 2003/11/EC bans Because flame retardants are different chemical groups of flame pentabromodiphenyl ether and designed to be stable in polymers retardants, there are also varying octabromodiphenyl ether in the or other treated materials over long European Union as of 15-August- periods (in order to ensure durable 2004. From then on both chemicals fire protection), they may be subject "may not be placed on the market to the more stringent testing re- or used as a substance or as a con- quirements of REACH. For many stituent of substances or of prepa- flame retardants, this will not rations in concentrations higher modify the current situation be- than 0,1 % by mass." And "articles cause EU Risk Assessment studies may not be placed on the market if are already underway or completed. they, or flame-retarded parts thereof, contain this substance in concen- The costs of registration, however, trations higher than 0,1 % by mass." may mean that it is no longer eco- Please see also the question on nomic to make some low-volume, WEEE and RoHS. specialist application flame retar- In the EU, polybrominated biphen- dants, with significant knock-on types and degrees of interactions yls (= PBBs, banned by 83/264/ effects for user industries, e.g. with living organisms. Even within EEC), tri-(2,3-dibromopropyl)- plastic components, electronics, a chemical group there can be large phosphate (= TRIS, banned by for whom key raw materials may differences in toxic effects, because 79/663/EEC) and tris-(aziridinyl)- thus cease to be available in Europe. depending on the level of molecular phosphineoxide (= TEPA, banned A particular issue is that imported interaction with cells, small changes by 83/264/EEC) are also not allowed consumer products or parts will not to a molecule can have huge effects. for clothing and similar products be subject to the same constraints, Many flame retardants do not have with skin contact. These products and may contain chemical additives to be labelled as dangerous sub- are no longer manufactured and not registered for use in Europe stances, which means that they have used in Europe.

28 Can flame retardants be released ment, a backcoating or a paint. from consumer products? In many cases the flame retardant will again be encapsulated within This is a very important aspect of a resin system which reduces the assessing a potential health risk likelihood of release. from flame retardants for consum- ers. There have been concerns that A study by the German Federal flame retardants are emitted from Material Testing Institute (BAM, fabrics or plastic materials, or being Berlin, 2003) looked at emissions released as dust particles by migra- of common flame retardants from tion, wear and tear. They might also consumer products to indoor air. be washed out by water from textiles The test chambers were operated or leached out by children sucking at realistic temperatures. In many on furniture or toys. One has to dis- cases they had extreme difficulties tinguish between three cases here: in even detecting flame retardants It came to the conclusion, that 8 of in the air. Certain types of flame them were definitely safe to use, Firstly, if the flame retardant is a retardants were found more often whereas the other 8 required more so-called "reactive" one, then it than others, mainly due to differ- data before a final conclusion could chemically reacts with the poly- ences in volatility. However, the be drawn. mer material or the fabric so that measured concentrations were very it is chemically bound in the fini- low and well below existing work- Kemmlein S, Hahn O (2003): Emission of Flame Retardants from Consumer shed article. Here a release is ex- place exposure limits or threshold Products and Building Materials. Project tremely unlikely. concentrations of concern. No 299 65 321, Federal Environmental Secondly, there are "additive" Agency (UBA), Berlin. flame retardants which are phys- A study by the Fraunhofer Institute National Research Council (2000): ically mixed into polymers and and TUV Germany looked at con- Toxicological Risks of Selected Flame- are therefore encapsulated by centrations of commonly used Retardant Chemicals. polymer. To what extent these are flame retardants in car interiors. Salthammer T, Wensing M (2002): Flame released depends on whether they None were detectable inside a 9- retardants in the indoor environment Part IV, Classification of experimental data migrate to the surface, their vola- month old car under normal use. from house dust, indoor air and chamber tility, water solubility and use. Under extreme conditions (car tests. Indoor Air 2002 Conference, Large, heavy molecules or very interior closed and heated to 65°C) Monterey, California, Vol. 2, 213-218 water insoluble substances will concentrations were 5 ... 10 times Sagunski H, Roßkamp E (2001): Indoor hardly be released. lower than recommended limits. air orientation values: Tris (2-chlorethyl)- Thirdly there are flame retardants phosphate. Bundesgesundheitsblatt, Vol. 45, 300-306 which are applied to the surface The Swiss Federal Health Office Hartmann P, Bürgi D, Giger W. (2004): of a product such as a textile treat- (BAG, Hartmann 2004) looked at Organophosphate flame retardants and concentrations of flame retardants plasticizers in indoor air. Chemosphere in indoor air from a variety of build- Vol, 57. pp. 781-787 ings, finding low levels, 50 ...1 000 times lower than recommended limits, and concluding ìthe risks are very low and that no additional measures have to be taken to minimise these risksî.

The US National Academy of Scien- ces commissioned a study on the toxicological risks of 16 commonly used flame retardants for furniture.

29 Flame Retardants Frequently asked Questions

Are flame retardants persistent in the environment?

Flame retardants require a certain chemical stability for their function: most of them are used in polymers which are processed at temperatures of 200 to 350 °C depending on the polymer. If they were not sufficiently stable, they would start to decompose during these processing steps. Furthermore, flame retardants are generally used in long living items like e.g. TV sets, compu- ters, cars, ships, construction products. Therefore, they have to last and provide fire safety for the whole life time of the product. Chemical stability is also an advantage, if you mercial use, only very few are likely How are flame retardants treated want to recycle polymers, because to accumulate in organisms. How- in European ecolabel schemes? then the recyclate retains the fire ever, levels observed are very low retardant properties. Unfortunately, compared to potential toxicity. Ecolabel schemes have been this necessary chemical stability us- Levels found to date, even for flame devised to promote environmentally ually relates to stability in the envi- retardants which have been in use friendly products by granting them ronment, i.e. persistence against for many years, are consistently special labels. These allow the con- attack by micro organisms, sunlight lower than those indicated by Risk sumer to identify such products or water. There are, however, some Assessments as posing significant easily. Ecolabel criteria are often exceptions to this general rule. risks. As EFRA agrees that these defined by environmental agencies flame retardants like other man- together with interested parties. made chemicals do not belong in They have no direct legal relevance Do flame retardants accumulate in the environment, we actively sup- though, i.e. their criteria are not living organisms? port product stewardship program- binding to any product manufac- mes to avoid the emissions into the turer. Ecolabels have been most Substances will generally only bio- environment. successful in product areas where accumulate if they are well soluble the consumer sees a direct environ- in fats and hardly soluble in water, mental impact or relevance, e.g. because water soluble chemicals recycled paper or solvent free paints. are easily removed from the body The most important ecolabels in via urine. Furthermore, bioaccumu- Europe are the Blue Angel in Ger- lative chemicals need to be taken many (one of the oldest schemes) up by the body from food, water or and the TCO-Label in Sweden. The air in order to accumulate (resorp- European "EcoFlower" has not tion). Once taken up, they also need gained wide spread acceptance yet, to be sufficiently stable and resistant although they have worked out to biochemical degradation. Only criteria for a number of products. if these conditions are fulfilled, bio- Some ecolabels like the Blue Angel accumulation can occur. From the do not allow halogenated flame various flame retardants in com- retardants (with exceptions) in

30 housings of E&E Equipment. The of PBDD/PBDF exceeding the limit initiative that reinforces the reduc- Ecoflower criteria, generally refer to values of the German Chemicals tion of emissions throughout the a list of risk phrases which are taken Banning Ordinance. Due to their manufacturing process by fostering from the European classification of chemical structure, the polybromi- a culture of continuous improve- dangerous substances, and which nated diphenylethers (PBDEs), can ment. will exclude the use of certain flame- be precursors of PBDF formation. retardants along with various other However, studies have shown that products. A number of flame retar- plastics containing decaBDE pro- For more information, see dants however are subject to none duced after 1993 can undergo sever- www.vecap.info. of the relevant health and environ- al recycling loops and still conform ment risk phrases. Another impor- to the German Chemicals Banning tant ecolabel in the field of electrical Ordinance. In general it is recom- and electronic equipment is TCO, mended to treat historical waste run by a Swedish trade union orga- containing PBDEs in thermal pro- nisation. They also apply some cesses like feedstock recycling, restrictions on halogenated flame metal smelters or modern inciner- retardants, but have recognised the ators. Incineration studies done by need for fire safety as well. the Forschungszentrum Karlsruhe in Germany have shown that plastics containing brominated flame What is the situation about flame retardants can be safely added to retardants and dioxins? state of the art municipal waste incinerators up to 3 % of the total In the 1980ies, it was found that feed without increasing the form- certain halogenated flame retar- ation of dioxins or furans. dants could react to form polybrominated dibenzodioxins (PBDDs) and dibenzofurans (PBDFs) during What is the industry doing to pre- their production, processing like vent the release of flame retardants extrusion or injection moulding, and to the environment? in case of fire or incineration. Com- prehensive studies have shown that The BFR industry has engaged in only very few brominated flame re- a voluntary programme with the tardants are likely to form amounts supply chain -including Small and Medium-sized Enterprises (SMEs)- aiming at controlling and reducing industrial emissions of the main commercial BFRs (deca-BDE, HBCD, TBBPA) into the environment. This programme entitled VECAP (Voluntary Emissions Control Action Programme) represents advance practice of the chemical user chain cooperation which will be required under the new EU chemicals policy of REACH. It is a product stewardship industry

31 Flame Retardants Frequently asked Questions

Recycling and Waste Management of Flame Retardants

Can materials containing flame retardants be safely disposed of with municipal wastes? Can they be burnt in household waste incinerators? Yes, they can. Materials which are treated with flame retardants can be handled in municipal waste incinerators, generating energy. Flame retardants delay and inhibit burning; they do not make materials incombustible. Therefore, waste incineration is no problem per se.

State of the art incinerators will remove any or physically bound to these, so that leaching pollutants formed during combustion to the or loss of significant levels of FRs from landfills required levels: e.g. acids like hydrogen bromide is very unlikely. or hydrochloric acid from halogenated flame retardants will be scrubbed from the flue Flame retardants in plastic wastes are also gasses, phosphorus compounds will primarily compatible with valorisation in metal smelters remain in the bottom ash as inorganic phos- and recovery of the precious metal and copper phates together with aluminium oxides from contents of mixed wastes via this route. The aluminium hydroxide. The very stringent low plastics content partly substitutes coke as a limit values for dioxins in flue gasses reducing agent, and partly provides smelter (0.1 ng (TEQ) / m³) are met for waste usually feed energy. See studies of valorisation of WEEE containing appreciable amounts of halogen, plastics published by smelter companies (i.e. 5 - 8 g Cl / kg from PVC and NaCl). This Umicore and Boliden. was also shown in studies where plastics waste, containing brominated flame retardants, was used together with municipal waste for energy Tange L, Brusselaers J, Hagelüken C. (2006): Eco- recovery without exceeding the dioxin/furan efficient solutions for flame retardant containing, limit values required. mixed plastics-metals WEEE, in particular resource Where domestic wastes are sent to landfill, recovery at an integrated metals smelter. Flame flame retardants will mostly remain within the Retardants 2006 Conference. Interscience. pp. treated materials, because they are chemically 33-46

32 of RoHS by the European Commis- cording to the WEEE directive. sion decision 2005/717/EC. Penta- Therefore, it is extremely difficult and Octa-BDE are already phased to reach a quality comparable to out by the marketing and use virgin material. Further, the econo- directive as of 15 August 2004 mics are under pressure due to (2003/11/EC). The Directive the scale of the process: 2002/96/EC on Waste Electrical and Mechanical recycling is done in Electronic Equipment (WEEE) installations up to 15 000 tons demands a "selective treatment" per year whereas plastics are for plastic materials and compo- produced in processes of up to nents of waste electrical and 300 000 tons per year. electronic equipment which contain For closed loop recycling the brominated flame retardants. sorting issue is much less severe, Member States had to transpose because the origin and composi- WEEE and RoHS into national tion of the plastics is known. Sev- legislation by August 2004. eral practical examples do exist like Technopolymer and Ricoh which mechanically recycle up to Can plastics containing flame 30% into their new products. retardants be mechanically Many plastics coming on the recycled? market which contain FRs are very suitable for mechanical recycling. Since flame retardants are generally more expensive than the base polymer, flame retarded plastics have an added value. Therefore flame retarded plastics should be recycled to flame retarded types again so that this eco- We need to make a difference bet- nomical advantage is not lost. ween closed loop where the produc- Studies on mechanical recycling er is the owner of the plastic like of ABS containing brominated copier machines and open loop like flame retardants and polypropyl- What do the European Directives TV and other equipment used in ene containing ammonium poly- on electrical and electronic equip- households: phosphate (APP) based flame ment (WEEE and RoHS) mean for retarded systems have shown flame retardants? For open loop where all mixed good recyclability: historical plastics return from the The mechanical recycling of ABS The Directive 2002/95/EC on the market, mechanical recycling is containing a brominated epoxy restriction of the use of certain haz- difficult because of the diverse oligomer flame retardant showed ardous substances in electrical and mixture of plastic materials. It is that the main properties like electronic equipment (RoHS) says a demanding task to sort plastics thermal and hydrolysis stability that "Member States shall ensure into individual polymer types like as well as the designed fire safety that, from 1 July 2006, new electrical PVC, PP, ABS etc. but what makes level were maintained after extrud- and electronic equipment put on it really challenging are further ing the material four times. the market does not contain lead, differences in pigments and ad- Polypropylene flame retarded mercury, cadmium, hexavalent ditives used - not only flame retar- with ammonium polyphosphate chromium, polybrominated bi- dants but also light stabilizers, (APP) can be recycled up to eight phenyls (PBB) or polybrominated compounding aides etc. All plas- times and maintains its fire safety diphenyl ethers (PBDE)." Deca-BDE tics containing Penta-, OctaBDE level (UL94 V0), melt flow proper- has been exempted from the scope and PBB's must be separated ac- ties and colour stability.

33 Flame Retardants Frequently asked Questions

Can flame retardants be chemically ment incinerated in a pilot plant recycled? for waste combustion is possible by quenching the flue gases in There are several examples of chem- water, collecting the hydrogen ical recycling of plastics containing bromide (HBr) with the option What is the industry doing to flame retardants: transforming it into elemental prevent the release of flame bromine as a basis for producing retardants to the environment? Rigid polyurethane foams con- brominated flame retardants. aining ammonium polyphosphate The BFR industry has engaged in a (APP) as a flame retardant can Flame retardants have been voluntary programme with the be chemically recycled by glycoly- shown to be fully compatible with supply chain -including Small and sis into a polyol, which can be recovery of waste electronic and Medium-sized Enterprises (SMEs)- reused as a polyol component. electrical plastics (WEEE) in metal aiming at controlling and reducing With the exception of a slightly smelters, enabling recycling of industrial emissions of the main enhanced acid number, no dis- precious metals and copper in commercial BFRs (deca-BDE, advantages occur during glycoly- circuitry, of antimony in flame HBCD, TBBPA) into the environ- sis in the presence of APP. retardants, and valorisation of the ment. This programme entitled plastics content as a reducing VECAP (Voluntary Emissions Con- A study carried out at ECN Hol- agent replacing use of coke and trol Action Programme) represents land showed that E&E plastics as an energy source (Umicore advance practice of the chemical can be treated in a pyrolysis/ gas- Hoboken ñ PlasticsEurope ñ user chain cooperation which will ification process safely and the EFRA trials 2005) be required under the new EU bromine can be recovered as HBr. chemicals policy of REACH. It is a product stewardship industry ini- Another pilot trial carried out in tiative that reinforces the reduction Japan by PWMI showed the same of emissions throughout the manu- results including the bromine re- facturing process by fostering a covery option. culture of continuous improvement.

Bromine recovery from waste For more information, see electrical and electronic equip- www.vecap.info.

34 Common Abbreviations for Flame Retardants

This table lists common abbreviations for flame retardants which are Abbr. Name CAS RN often used in the technical literature. In addition to these, often trade AP Ammonium phosphates names are used to denote flame retardants (just as you say "aspirin" APP Ammonium polyphosphate 68333-79-9 when you in fact mean a headache pill containing acetylsalicylic acid). ATH Aluminium trihydroxide 21645-51-2 These trade names often also look like chemical abbreviations. ATO Antimonytrioxide 1309-64-4 However, since these are manufacturer specific and quite numerous, BDP Bisphenol-A- bis- diphenylphosphate 5945-33-5, 181028-79-5 we have not included them here. DBDEDecabromodiphenyl ether 1163-19-5

HBCDHexabromocyclododecane 25637-99-4

MCPPMedium-chain chlorinated paraffins 85535-85-8

MDHMagnesium hydroxide 1309-42-8

OBDEOctabromodiphenyl ether 32536-52-0

PBDEPolybrominated diphenyl ethers in general

RDP Resorcinol bis-diphenylphosphate 57583-54-7, 125997-21-9

RP Red Phosphorus 7723-14-0

SCPP Short-chain chlorinated paraffins 85535-84-8

TBBPATetrabromobisphenol-A 79-94-7

TBP Tri-n-butyl phosphate 126-73-8

TCEP Tris (2-chloroethyl) phosphate 115-96-8

TCP Tricresyl phosphate 1330-78-5

TCPP Tris (chloroiso-propyl) phosphate 13674-84-5

TDCPTris(1,3-dichloro-2-propyl)phosphate 13674-87-8

TPP Triphenyl phosphate 115-86-6

On www.flameretardants.eu you find fact sheets for the major flame retardants.

35 Flame Retardants Frequently asked Questions

Literature and Further Reading

Ash M., Ash I. (1997): European Union (2003): Simonson M., Blomqvist P., Bodizar The Index of Flame Retardants. Directive 2003/11/EC of the Euro- A. Möller K., Rosell L., Tullin C., Gower. pean Parliament and of the council Stripple H., Sundqvist J. (2000): of 6 February 2003 amending for Fire-LCA Model: TV Case Study. SP Bate R. (1997): the 24th time Council directive Swedish Testing Institute. What Risk? Science, Politics & Pu- 76/769/EEC relating to restrictions blic Health. Butterworth/ Heine- on the marketing and use of certain Simonson M., Andersson P., mann. dangerous substances and prepara- Stripple H., (2000): tions. Official Journal of the Euro- Fire-LCA Model: Furniture Study. Bromine Science and pean Union. pp. 42-45 SP Swedish National Testing and Environmental Forum (2002): Research Institute and IVL Swedish Bromine: Frequently Asked Ques- European Union (1967): Environmental Research Institute, tions. Brussels. Council Directive 67/548/EEC of 27 Report 2003: 22. www.sp.se/fire June 1967 on the approximation of Brushlinski N., Sokolov S., laws, regulations and administrative Stevens G, Emsley A, Lim L, Wagner P (2000): provisions relating to the classifi- Williams P (2006): World fire statistics at the end of cation, packaging and labelling of The benefits of fire counter- 20th century. Brennpunkt Edition. dangerous substance. Official Jour- measures in the UK and Europe nal P 196. pp. 1-98 from a consideration of UK and de Wit C. (2002): International fire statistics. Flame An overview of brominated flame European Union (2003): Retardants 2006 Conference. retardants in the environment. Directive 2002/95/EC of the Euro- Interscience. pp. 235-247 Chemosphere. pp. 583-624 pean Parliament and of the council of 27 January 2003 on the restriction Troitzsch J. (2004): DTI (1999): of the use of certain hazardous Plastics Flammability Handbook. A Guide to the Furniture and Fur- substances in electrical and Hanser Publishers, Munich. nishings (Fire Safety) Regulations. electronic equipment. Official ISBN 3-446-21308-2 UK Department of Trade and Journal of the European Union. Industry. pp. L37/19-23

ECOSA (2001): Grand F., Wilkie C. (2000): Priorities for consumer safety in Fire Retardancy of Polymeric Websites on flame retardants: the EU. Agenda for Action ECOSA. Materials. Marcel Dekker. www.flameretardants.eu www.bsef.com European Union (2003): Horrocks A., Price D. (2001): www.pefrc.org Directive 2002/96/EC of the Fire retardant materials. CRC Press. European Parliament and of the Websites for fire safety: Council on waste electrical and National Research Council (2000): www.acfse.org (Europe) electronic equipment (WEEE). Toxicological Risks of Selected www.nfpa.org (USA) Official Journal of the European Flame-Retardant Chemicals. www.vfdb.de (Germany) Union. pp. L37/24-38 National Academy Press. www.gtfi.org (France)

36 EFRA Members

Albemarle Europe Sprl DSM Melamine Parc Scientifique Einstein Poststraat 1, Sittard Rue du Bosquet, 9 P O Box 43 B-1348 Louvain-la-Neuve NL-6130 AA Sittard Telephone : +32 10 48 17 11 Telephone : +31 464 77 38 52 Fax : +32 10 48 17 17 Fax : +31 464 77 30 49 Luzenac Website : www.albemarle.com Website : www.dsm.nl 2 Place E. Bouillères B.P. 1162 F-31036 Toulouse Cedex 1 Telephone : +33 5 615 02 020 Fax : +33 5 615 02 055 Website : www.luzenac.com Budenheim Iberica Extramuros S/N Eurobrom B.V. ICL-IP Zaragoza E- 50784 La Zaida Fosfaatweg 48 Telephone : +34 976 17 84 12 NL-1013 BM Amsterdam Fax : +34 976 17 87 51 Telephone : +31 20 800 58 00 Nabaltec Website : www.budenheim.es Fax : +31 20 800 58 05 P O Box 1860 Website : www.iclfr.com D-92409 Schwandorf Telephone : +49 9431 530 Fax : +49 9431 53310 Website : www.nabaltec.de

Chemtura Italmatch Chemicals S.p.A. Tenax Road - Trafford Park Via Pietro Chiesa, 7/13 (Piano 8°) GB-M17 1WT Manchester Torri Piane - San Benigno PCC Rokita Telephone : +44 161 875 31 15 I-16149 Genova Ul Sienkiewicza 4 Fax : +44 161 8753177 Telephone : +39 010 64208210 PL-56-120 Brzeg Dolny Website : www.chemtura.com Fax : +39 010 4695296 Telephone : +48 71 319 25 80 Website : www.italmatch.it Fax : + 48 71 319 25 50 Website : www.rokita.com

Ciba Specialty Chemicals Inc. CH-4002 Basel Rhodia Consumer Switzerland Specialities Ltd. Tel +41 (61) 636 6100 Joseph Storey & Co Ltd PO Box 80 Fax +41 (61) 636 9007 Moor Lane Trinity Street Website: www.cibasc.com GB-LA1 1QQ Lancaster UK-West Midlands B69 4LN Telephone : +44 1524 63252 Telephone : +44 121 541 3720 Fax : + 44 1524 381805 Fax : +44 121 541 3853 Website : www.josephstorey.co.uk Website : www.rhodia-ppd.com

Clariant Produkte (D) GmbH Lanxess Supresta Netherlands B.V. PA, Business Flame Retardants Leverkussen Bayerwerk Office Park de Hoef Industriestrasse, Chemiepark Knapsack Building K10 Hoefseweg 1 D-50354 Huerth D-51368 Leverkussen NL-3821 AE Amersfoort Telephone : +49 2233 48 61 14 Telephone : +49 214 30 27 355 Telephone : +31 33 45 34 580 Fax : +49 2233 412 36 Fax : +49 214 30 55 657 Fax : +31 33 45 34 578 Website : www.exolit.com Website : www.rubber.bayer.de Website : www.supresta.com

37 EFRA - The European Flame Retardants Association

Chemistry making a world of difference

EFRA c/o Cefic aisbl Avenue E. van Nieuwenhuyse 4 B - 1160 Brussels tel + 32 2 676 72 86 fax+ 32 2 676 73 92 [email protected] www.flameretardants.eu