Octabromodiphenyl ether
From Wikipedia, the free encyclopedia
| Octabromodiphenyl ether | |
|---|---|
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| Other names | OctaBDE, Octa-BDE |
| Identifiers | |
| CAS number | [32536-52-0] |
| Properties | |
| Molecular formula | C12H2Br8O |
| Molar mass | 801.31 g/mol |
| Appearance | white solid |
| Density | 2.9 g/cm3 |
| Solubility in water | not soluble |
| Hazards | |
| R-phrases | R61, R62 |
| S-phrases | S53, S45 |
| Related compounds | |
| Related polybrominated diphenyl ethers | Decabromodiphenyl ether, Pentabromodiphenyl ether |
| Related compounds | diphenyl ether |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Octabromodiphenyl ether (octaBDE, octa-BDE, OBDE, octa, octabromodiphenyl oxide, OBDPO) is a brominated flame retardant which belongs to the group of polybrominated diphenyl ethers (PBDEs).
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[edit] Composition, uses, and production
Commercial octaBDE (also known as "Octabrom") is a technical mixture of different PBDE congeners having an average of 7.2 to 7.7 bromine atoms per molecule of diphenyl ether.[1] The predominant congeners in commercial octaBDE are those of heptabromodiphenyl ether and octaBDE.[1][2] The term octaBDE alone refers to isomers of octabromodiphenyl ether (PBDE congener numbers 194-205); the Infobox displays BDE-203 (2,2’,3,4,4’,5,5’,6-octabromodiphenyl ether).[3]
OctaBDE is used in conjunction with antimony trioxide as a flame retardant in the housings of electrical and electronic equipment, mainly in the plastic acrylonitrile butadiene styrene, but also in high impact polystyrene, polybutylene terephthalate and polyamides.[4] Typically 12–15% of the weight of the final product will consist of octaBDE.[4]
The annual demand worldwide was estimated as 3,790 tonnes in 2001, of which Asia accounted for 1,500 tonnes, the Americas 1,500 tonnes, and Europe 610 tonnes.[5] The United Nations Environment Programme reports "Since 2004, it [octaBDE] is no longer produced in the EU, USA and the Pacific Rim and there is no information that indicates it is being produced in developing countries."[2]
[edit] Environmental chemistry
OctaBDE is released by different processes into the environment, such as emissions from the manufacture of octaBDE-containing products and from the products themselves.[2] Elevated concentrations can be found in air, water, soil, food, sediment, sludge, and dust.[2][6][7]
In the environment, "photolysis, anaerobic degradation and metabolism in biota" can cause debromination of octaBDE, which produces PBDEs with fewer bromine atoms "which may have higher toxicity and bioaccumulation potential."[2]
[edit] Exposures and health effects
OctaBDE may enter the body by ingestion or inhalation.[3] It is "stored mainly in body fat" and may stay in the body for years.[3] In an investigation carried out by the WWF, "the brominated flame retardant chemical (PBDE 153), which is a component of the penta- and octa- brominated diphenyl ether flame retardant products" was found in all blood samples of 14 ministers of health and environment of 13 European Union countries.[8]
The chemical has no proven health effects in humans; however, based on animal experiments, octaBDE may have effects on "the liver, thyroid, and neurobehavioral development."[3]
[edit] Governmental actions
The European Union has carried out a comprehensive risk assessment under the Existing Substances Regulation 793/93/EEC.[4] As a consequence, the EU has banned the use of octaBDE since 2004.[9]
In the United States, as of 2005, "no new manufacture or import of" pentaBDE and octaBDE "can occur... without first being subject to EPA [i.e., United States Environmental Protection Agency ] evaluation."[10] As of mid-2007, a total of eleven states in the U.S. had banned octaBDE.[11]
It has been proposed that octaBDE be added to the Stockholm Convention as it meets the criteria for the so-called persistent organic pollutants of persistence, bioaccumulation and toxicity.[2]
[edit] Alternatives
Alternatives to octaBDE include tetrabromobisphenol A, 1,2-bis (pentabromophenoxy) ethane, 1,2-bis(tribromophenoxy)ethane, triphenyl phosphate, resorcinol bis(diphenylphosphate), and brominated polystyrene; however, for each of these "the existing data on toxicological and ecotoxicological effects are fewer than for octabromodiphenyl ether."[12]
[edit] References
- ^ a b United States Patent and Trademark Office. Melting point enhancement of partially brominated diphenyl oxide mixtures. US Patent 5,000,879 issued on March 19, 1991.
- ^ a b c d e f Ad hoc working group on C-Octabromodiphenyl ether under the Persistent Organic Pollutants Review Committee of the Stockholm Convention. Draft risk profile: commercial octabromodiphenyl ether. United Nations Environment Programme, August 2007.
- ^ a b c d Agency for Toxic Substances and Disease Registry. Toxicological Profile for Polybrominated Biphenyls and Polybrominated Diphenyl Ethers (PBBs and PBDEs). Atlanta, GA: U.S. Department of Health and Human Services, Public Health Service, September 2004.
- ^ a b c European Union risk assessment report. Diphenyl ether, octabromo derivative. Luxembourg: Office for Official Publications of the European Communities, 2003. Publication EUR 20403 EN.
- ^ Bromine Science and Environmental Forum. Major Brominated Flame Retardants Volume Estimates: Total Market Demand By Region in 2001. 21 January 2003.
- ^ Hale RC, La Guardia MJ, Harvey E, Gaylor MO, Mainor TM (2006): Brominated flame retardant concentrations and trends in abiotic media. Chemosphere. 64(2):181-6. PMID 16434082
- ^ Stapleton, Heather M., et al. Polybrominated Diphenyl Ethers in House Dust and Clothes Dryer Lint. Environmental Science & Technology 39(4), 925-931, 2005.
- ^ WWF Detox Campaign. Bad Blood? A Survey of Chemicals in the Blood of European Ministers. October 2004.
- ^ Directive 2003/11/Ec of the European Parliament and of the Council of 6 February 2003 amending for the 24th time Council Directive 76/769/EEC relating to restrictions on the marketing and use of certain dangerous substances and preparations (pentabromodiphenyl ether, octabromodiphenyl ether). Official Journal of the European Union 15.2.2003.
- ^ U.S. Environmental Protection Agency. Polybrominated diphenylethers (PBDEs). "Last updated on Thursday, August 2nd, 2007." Accessed 2007-10-26.
- ^ Maine Joins Washington, Bans PBDEs. Washington, DC: National Caucus of Environmental Legislators, June 18, 2007.
- ^ Risk & Policy Analysts Limited. Octabromodiphenyl Ether. Risk Reduction Strategy and Analysis of Advantages and Drawbacks. Final Report. Prepared for Department for Environment, Food and Rural Affairs, United Kingdom, June 2002.
