Brominated flame retardant

Types of compounds

Many different BFRs are produced synthetically with widely varying chemical properties. There are several groups:

• Polybrominated diphenyl ethers (PBDEs): DecaBDE, OctaBDE (not manufactured anymore), PentaBDE (not manufactured anymore, the first BFR, commercialized in the 1950s)
• Polybrominated biphenyl (PBB), not manufactured anymore
• Brominated cyclohydrocarbons
• Other brominated flame retardants with different properties and mechanisms

Decabromodiphenyl ether (Deca-BDE or DeBDE) - In August 2012, the UK authorities proposed decabromodiphenyl ether (Deca-BDE or DeBDE) as a candidate for Authorisation under the EU's regulatory regime on chemicals, REACH. On 5 July 2013 ECHA withdrew Deca-BDE from its list of priority substances for Authorisation under REACH, therefore closing the public consultation. On 1 August 2014, ECHA submitted a restriction proposal for Deca-BDE. The agency is proposing a restriction on the manufacture, use and placing on the market of the substance and of mixtures and articles containing it. On 17 September 2014, ECHA submitted the restriction report which initiates a six months public consultation. On 9 February 2017, the European Commission adopted Regulation EU 2017/227. Article 1 of this regulation states that Regulation (EC) No 1907/2006 is amended to include a ban on the use of decaBDE in quantities greater than 0.1% by weight, effective from 2 March 2019. Products placed on the market prior to 2 March 2019 are exempt. Furthermore, the use decaBDE in aircraft is permissible until 2 March 2027.

Hexabromocyclododecane (HBCD or HBCDD) is a ring consisting of twelve carbon atoms with six bromine atoms tied to the ring. The commercially used HBCD is in fact a mixture of different isomers. HBCD is toxic to water-living organisms. The UNEP Stockholm Convention has listed HBCD for elimination, but allowing a temporary exemption for the use in polystyrene insulation foams in buildings.

Tetrabromobisphenol A (TBBPA or TBBP-A) is mainly used in printed circuit boards, as a reactive flame retardant. Since TBBPA is chemically bound to the resin of the printed circuit board, it is less easily released than the loosely applied mixtures in foams such that an EU risk assessment concluded in 2005 that TBBPA poses no risk to human health in that application. TBBPA is also used as an additive in acrylonitrile butadiene styrene (ABS).

Contents in plastics

Content of brominated flame retardants in different polymers:

Types of applications

The electronics industry accounts for the greatest consumption of BFRs. In computers, BFRs are used in four main applications: in printed circuit boards, in components such as connectors, in plastic covers, and in electrical cables. BFRs are also used in a multitude of products, including, but not exclusively, plastic covers of television sets, carpets, pillows, paints, upholstery, and domestic kitchen appliances.

Environmental and safety issues

Main article: Polybrominated diphenyl ethers#Health and environmental concerns

Generally, governments have determined that brominated fire retardants are not harmful to human health in the exposure amounts assessed.

References

References

1. "Flammschutz Online - the flame retardants market".
2. Michael J. Dagani, Henry J. Barda, Theodore J. Benya, David C. Sanders: ''Bromine Compounds'', Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH, Weinheim. {{doi. 10.1002/14356007.a04_405
3. (9 February 2017). "Commission Regulation (EU) 2017/227". Official Journal of the European Union.
4. "COP Decisions".
5. "EU Risk Assessment Report of 2,2',6,6'-tetrabromo-4,4'-isopropylidenediphenol (tetrabromobisphenol-A or TBBP-A) Part II – human health". Institute for Health and Consumer Protection.
6. Pedro Arias (2001): ''Brominated flame retardants – an overview''. The Second International Workshop on Brominated Flame Retardants, Stockholm
7. (2021). "Ullmann's Encyclopedia of Industrial Chemistry".
8. (8 May 2017). "Public Health Statement for PBDEs". Agency for Toxic Substances and Disease Registry, US Centers for Disease Control and Prevention.
9. (14 September 2023). "Polybrominated diphenyl ethers (PBDEs) - information sheet". Health Canada, Government of Canada.
10. EFSA Panel on Contaminants in the Food Chain. (24 January 2024). "Update of the risk assessment of polybrominated diphenyl ethers (PBDEs) in food". EFSA Journal.