Octabromodiphenyl ether

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Octabromodiphenyl ether
BDE-203.svg
Names
Other names
OctaBDE, Octa-BDE
Identifiers
32536-52-0 YesY
Properties
C12H2Br8O
Molar mass 801.38 g/mol
Appearance white solid
Density 2.9 g/cm3
not soluble
Hazards
R-phrases R61, R62
S-phrases S53, S45
Related compounds
Decabromodiphenyl ether, Pentabromodiphenyl ether
Related compounds
diphenyl ether
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 YesY verify (what isYesY/N?)
Infobox references

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).

Composition, uses, and production[edit]

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]

Composition of commercial octaBDE [4]
Structure Congener Name Fraction
Structure of BDE-153 BDE-153 2,2′,4,4′,5,5′-hexa-
bromodiphenyl ether
0.15–8.7%
Structure of BDE-154 BDE-154 2,2′,4,4′,5,6′-hexa-
bromodiphenyl ether
0.04–1.1%
Structure of BDE-171 BDE-171 2,2′,3,3′,4,4′,6-hepta-
bromodiphenyl ether
0.17–1.8%
Structure of BDE-180 BDE-180 2,2′,3,4,4′,5,5′-hepta-
bromodiphenyl ether
n.d.–1.7%
Structure of BDE-183 BDE-183 2,2′,3,4,4′,5′,6-hepta-
bromodiphenyl ether
13–42%
Structure of BDE-196 BDE-196 2,2′,3,3′,4,4′,5,6′-octa-
bromodiphenyl ether
3.1–10.5%
Structure of BDE-197 BDE-197 2,2′,3,3′,4,4′,6,6′-octa-
bromodiphenyl ether
11–22%
Structure of BDE-203 BDE-203 2,2′,3,4,4′,5,5′,6-octa-
bromodiphenyl ether
4.4–8.1%
Structure of BDE-206 BDE-206 2,2′,3,3′,4,4′,5,5′,6-nona-
bromodiphenyl ether
1.4–7.7%
Structure of BDE-207 BDE-207 2,2′,3,3′,4,4′,5,6,6′-nona-
bromodiphenyl ether
11–12%
Structure of BDE-209 BDE-209 Deca-
bromodiphenyl ether
1.3–50%

Only congeners with more than 1% listed.

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.[5] Typically 12–15% of the weight of the final product will consist of octaBDE.[5]

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.[6] 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]

Environmental chemistry[edit]

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][7][8]

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]

Exposures and health effects[edit]

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.[9]

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]

Governmental actions[edit]

The European Union has carried out a comprehensive risk assessment under the Existing Substances Regulation 793/93/EEC.[5] As a consequence, the EU has banned the use of octaBDE since 2004.[10]

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."[11] As of mid-2007, a total of eleven states in the U.S. had banned octaBDE.[12]

In May 2009, commercial octaBDE was added to the Stockholm Convention as it meets the criteria for the so-called persistent organic pollutants of persistence, bioaccumulation and toxicity.

Alternatives[edit]

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."[13]

References[edit]

  1. ^ 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.
  2. ^ a b c d e 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.
  3. ^ 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.
  4. ^ M. J. La Guardia, R. C. Hale, E. Harvey: Detailed Polybrominated Diphenyl Ether (PBDE) Congener Composition of the Widely Used Penta-, Octa-, and Deca-PBDE Technical Flame-retardant Mixtures, Environ. Sci. Technol., 2006, 40, 6247–6254, doi:10.1021/es060630m.
  5. ^ 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.
  6. ^ Bromine Science and Environmental Forum. Major Brominated Flame Retardants Volume Estimates: Total Market Demand By Region in 2001. 21 January 2003.
  7. ^ 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. doi:10.1016/j.chemosphere.2005.12.006 PMID 16434082
  8. ^ Stapleton, Heather M., et al. Polybrominated Diphenyl Ethers in House Dust and Clothes Dryer Lint. Environmental Science & Technology 39(4), 925-931, 2005.
  9. ^ WWF Detox Campaign. Bad Blood? A Survey of Chemicals in the Blood of European Ministers. October 2004.
  10. ^ 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.
  11. ^ U.S. Environmental Protection Agency. Polybrominated diphenylethers (PBDEs). "Last updated on Thursday, August 2nd, 2007." Accessed 2007-10-26.
  12. ^ Maine Joins Washington, Bans PBDEs. Washington, DC: National Caucus of Environmental Legislators, June 18, 2007.
  13. ^ 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.