Brominated flame retardant
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'''Brominated flame retardants''' are a group of [[flame retardant]]s that consist of organic compounds containing [[bromine]].
==History==
Brominated are the major type of chemical flame retardants, and are very effective in plastics and textile applications. They are applied to prevent electronics, clothes and furniture from catching fire.
Brominated flame retardants is the designated name for a group of brominated organic substances that have an inhibitory effect on the ignition of combustible organic materials. BFRs are commonly used in electronic products as a means of reducing the flammability of the product. Bromine based flame retardants are applied to 2.5 million tons of polymers annually, with the annual consumption of PBDEs alone being in excess of 40,000 metric tons. North American industry used about 34,000 metric tons of PBDEs in 1999, making it the largest user of these additives globally<ref>[[BSEF]], http://www.bsef.com/docs/BFR_vols_2001.doc</ref>; however, a significant proportion of the flame-retarded products manufactured in North America is destined for international markets. The electronics industry accounts for the greatest consumption of BFRs. In computers, BFRs are used in four main applications: in [[printed circuit board]]s, in components such as [[connector]]s, in plastic covers, and in [[cable]]s. BFRs are also used in a multitude of products, including, but not exclusively, plastic covers of television sets, carpets, paints, upholstery, and domestic kitchen appliances. BFRs have such a widespread number of applications because they are incredibly effective at fire prevention. In addition to reducing the likelihood that an item will ignite, brominated flame retardants hinder the spread of the fire, and provide valuable extra time in the early stages of a fire when it is much easier to escape. A room fire can very quickly escalate to the point where enough heat is generated that all combustible material in the room bursts into flames. This situation is known as [[flashover]] and can occur in a matter of minutes from ignition. Brominated flame retardants slow down the initial burn rate and thereby can help increase the time to flashover, giving the occupants more time to escape.
==Types of compounds==
They are produced [[organic synthesis|synthetically]] in 70 variants with very varying chemical properties. There are several groups:
* ''polybrominated diphenyl ether'' or [[PBDE]] ([[DecaBDE]], [[OctaBDE]] (not manufactured anymore), [[PentaBDE]](not manufactured anymore)),
* ''polybrominated biphenyl'', or [[Polybrominated biphenyl|PBB]](not manufactured anymore)
* ''brominated cyclohydrocarbons''
[[Decabromodiphenyl ether]] (''Deca-BDE'' or ''DeBDE'') is regarded as a not-dangerous substance (no risk-phrase awarded under EU regulation 67/769).
[[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 [[isomer]]s. HBCD is toxic to water-living [[organism]]s. Studies carried out on a HBCD product that is no longer manufactured indicate that Humans can develop [[allergy]] at skin contact.{{Fact|date=July 2007}} This is not the case anymore with the current HBCD-based products.
[[Tetrabromobisphenol A]] (''TBBPA'' or ''TBBP-A'') is regarded as toxic to water environment.{{Fact|date=July 2007}} This flame retardant is mainly used in [[printed circuit board]]s, as a reactive. Since TBBPA is chemically bound to the resin of the printed circuit board, it cannot be released and therefore poses no risk for the environment or for human health. TBBPA is also used as an additive in [[acrylonitrile butadiene styrene]] (ABS). EU risk assessment concluded in 2005 that TBBPA poses no risk to human health in that application.{{Fact|date=July 2007}}
== Contents in plastics ==
Content of brominated flame retardants in different polymers<ref>Pedro Arias (2001): ''Brominated flame retardants – an overview''. The Second International Workshop on Brominated Flame Retardants, Stockholm</ref>:
{| class="prettytable"
! Polymer
! Content [%]
! Substances
|-
| [[Polystyrene]] foam
| 0,8–4
| HBCD
|-
| [[High impact polystyrene]]
| 11–15
| DecaBDE, brominated polystyrene
|-
| [[Epoxy resin]]
| 0-0,1
| TBBPA
|-
| [[Polyamide]]s
| 13–16
| DecaBDE, brominated polystyrene
|-
| [[Polyolefin]]s
| 5–8
| DecaBDE, propylene dibromo styrene
|-
| [[Polyurethane]]s
| n/a
| No brominated FR available
|-
| [[Polyterephthalate]]
| 8–11
| Brominated polystyrene
|-
| Unsaturated [[polyester]]s
| 13–28
| TBBPA
|-
| [[Polycarbonate]]
| 4–6
| Brominated polystyrene
|-
| Styrene [[copolymer]]s
| 12–15
| Brominated polystyrene
|}
==Testing for BFR in plastics==
Until recently testing for BFR has been cumbersome. Cycle time, cost and level of expertise required for the test engineer has precluded the implementation of any screening of plastic component in a manufacturing or in a product qualification/validation environment.
Recently, with the introduction of a new analytical instrument [[IA-Mass]], screening of plastic material alongside manufacturing line becomes possible. A 5 min. detection cycle and a 20 min. quantification cycle is available to test and to qualify plastic parts as they reach the assembly line. However, IA-Mass allow to identify the presence of Bromine, but does not allow to characterize the actual BFR present in the plastic matrix.
==References==
*{{cite journal
| author= Kyle D'Silva, Alwyn Fernandes and Martin Rose
| title = Brominated Organic Micropollutants—Igniting the Flame Retardant Issue
| journal = [[Critical Reviews in Environmental Science and Technology]]
| year = 2004
| volume = 34
| issue = 2
| pages = 141–207
| doi = 10.1080/10643380490430672}}
*{{cite journal
| author= Robin Law, Martin Kohler, Norbert Heeb, Andreas Gerecke, Peter Schmid, Stefan Voorspoels, Adrian Covaci, Georg Becher, Karel Janák, and Cathrine Thomsen
| title = Hexabromocyclododecane challenges scientists and regulators
| journal = [[Critical Reviews in Environmental Science and Technology]]
| year = 2005
| volume = 34
| issue = 2
| pages = 281A–287A
| url = http://pubs.acs.org/isubscribe/journals/esthag-a/39/i13/html/070105feature_law.html
| pmid =16053062}}
*{{cite journal
| author= Cynthia A. de Wit
| title = An overview of brominated flame retardants in the environment
| journal = [[Chemosphere (journal)|Chemosphere]]
| year = 2002
| volume = 46
| issue = 5
| pages = 583–624
| doi = 10.1016/S0045-6535(01)00225-9}}
<references/>
==Further reading==
* {{cite journal | doi = 10.1289/ehp.6559 | title = Brominated Flame Retardants: Cause for Concern? | year = 2003 | author = Birnbaum, Linda S. | journal = Environmental Health Perspectives}}
== External links ==
* [http://www.fireretardant-forum.com The Fire Retardant Forum] Meeting place for all Flame Retardant related issues; for producers and users of flame retardants.
* [http://www.bsef.com Bromine Science and Environmental Forum]
* [http://www.ebfrip.org European Brominated Flame Retardant Industry Panel]
[[Category:Bromine compounds]]
[[Category:Organobromides]]
[[Category:Flame retardants]]
[[Category:Persistent organic pollutants]]
[[cs:Bromované zpomalovače hoření]]
[[da:Bromeret flammehæmmer]]
[[fr:Agents ignifuges bromés]]
[[nl:Gebromeerde vlamvertrager]]
[[no:Bromerte flammehemmere]]