View source for Octabromodiphenyl ether

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| ImageFile = Octabromdiphenylether.svg
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| OtherNames = OctaBDE, Octa-BDE
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| CASNo = 32536-52-0
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| Formula = C<sub>12</sub>H<sub>2</sub>Br<sub>8</sub>O
| MolarMass = 801.31 g/mol
| Appearance = white solid
| Density = 2.9 g/cm<sup>3</sup>
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| RPhrases = {{R61}}, {{R62}} <!-- from 67/548/EEC -->
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| OtherFunctn = [[Decabromodiphenyl ether]], [[Pentabromodiphenyl ether]]
| Function = [[polybrominated diphenyl ether]]s
| OtherCpds = [[diphenyl ether]] }}
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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 ether]]s (PBDEs).

==Composition, uses, and production==
'''Commercial octaBDE''' (also known as "Octabrom") is a technical mixture of different PBDE [[congener]]s having an average of 7.2 to 7.7 bromine atoms per molecule of diphenyl ether.<ref name=USPTO1991>United States Patent and Trademark Office. [http://patft.uspto.gov/netacgi/nph-Parser?u=%2Fnetahtml%2Fsrchnum.htm&Sect1=PTO1&Sect2=HITOFF&p=1&r=1&l=50&f=G&d=PALL&s1=5000879.PN.&OS=PN/5000879&RS=PN/5000879 Melting point enhancement of partially brominated diphenyl oxide mixtures.] US Patent 5,000,879 issued on March 19, 1991.</ref>  The predominant congeners in commercial octaBDE are those of heptabromodiphenyl ether and octaBDE.<ref name=USPTO1991/><ref name=UNEP2007>Ad hoc working group on C-Octabromodiphenyl ether under the Persistent Organic Pollutants Review Committee of the Stockholm Convention. [http://www.pops.int/documents/meetings/poprc_3/meetingdocs/poprc3_doc/14/poprc3_14e.pdf Draft risk profile: commercial octabromodiphenyl ether.] United Nations Environment Programme, August 2007.</ref> The term '''octaBDE''' alone refers to [[isomer]]s of octabromodiphenyl ether (PBDE congener numbers 194–205); the Infobox displays BDE-203 (2,2’,3,4,4’,5,5’,6-octabromodiphenyl ether).<ref name=ATSDR2004>Agency for Toxic Substances and Disease Registry. [http://www.atsdr.cdc.gov/toxprofiles/tp68.html 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.</ref>

{| class="wikitable" 
|+ Composition of commercial octaBDE <ref>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}}.</ref>
! Structure
! Congener
! Name
! Fraction
|-
| [[File:BDE-153.svg|150px|Structure of BDE-153]]
| BDE-153
| 2,2′,4,4′,5,5′-hexa-<br />bromodiphenyl ether
| 0.15–8.7 %
|-
| [[File:BDE-154.svg|150px|Structure of BDE-154]]
| BDE-154
| 2,2′,4,4′,5,6′-hexa-<br />bromodiphenyl ether
| 0.04–1.1 %
|-
| [[File:BDE-171.svg|150px|Structure of BDE-171]]
| BDE-171
| 2,2′,3,3′,4,4′,6-hepta-<br />bromodiphenyl ether
| 0.17–1.8 %
|-
| [[File:BDE-180.svg|150px|Structure of BDE-180]]
| BDE-180
| 2,2′,3,4,4′,5,5′-hepta-<br />bromodiphenyl ether
| n.d.–1.7 %
|-
| [[File:BDE-183.svg|150px|Structure of BDE-183]]
| BDE-183
| 2,2′,3,4,4′,5′,6-hepta-<br />bromodiphenyl ether
| 13–42 %<!--a unknown amount of co-eluditing BDE-175 included-->
|-
| [[File:BDE-196.svg|150px|Structure of BDE-196]]
| BDE-196
| 2,2′,3,3′,4,4′,5,6′-octa-<br />bromodiphenyl ether
| 3.1–10.5 %
|-
| [[File:BDE-197.svg|150px|Structure of BDE-197]]
| BDE-197
| 2,2′,3,3′,4,4′,6,6′-octa-<br />bromodiphenyl ether
| 11–22 %
|-
| [[File:BDE-203.svg|150px|Structure of BDE-203]]
| BDE-203
| 2,2′,3,4,4′,5,5′,6-octa-<br />bromodiphenyl ether
| 4.4–8.1 %
|-
| [[File:BDE-206.svg|150px|Structure of BDE-206]]
| BDE-206
| 2,2′,3,3′,4,4′,5,5′,6-nona-<br />bromodiphenyl ether
| 1.4–7.7 %
|-
| [[File:BDE-207.svg|150px|Structure of BDE-207]]
| BDE-207
| 2,2′,3,3′,4,4′,5,6,6′-nona-<br />bromodiphenyl ether
| 11–12 %
|-
| [[File:BDE-209.svg|150px|Structure of BDE-209]]
| BDE-209
| Deca-<br />bromodiphenyl ether
| 1.3–50 %
|}
<small>Only congeners with more than 1 % listed.</small>


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 [[Polystyrene#Copolymers|high impact polystyrene]], [[polybutylene terephthalate]] and [[polyamide]]s.<ref name=EU2003>[http://ecb.jrc.it/DOCUMENTS/Existing-Chemicals/RISK_ASSESSMENT/REPORT/octareport014.pdf European Union risk assessment report. Diphenyl ether, octabromo derivative.] Luxembourg: Office for Official Publications of the European Communities, 2003.  Publication EUR 20403 EN.</ref> Typically 12–15% of the weight of the final product will consist of octaBDE.<ref name=EU2003/>

The annual demand worldwide was estimated as 3,790 [[tonne]]s in 2001, of which Asia accounted for 1,500 tonnes, the Americas 1,500 tonnes, and Europe 610 tonnes.<ref>Bromine Science and Environmental Forum. [http://www.bsef.com/docs/BFR_vols_2001.doc Major Brominated Flame Retardants Volume Estimates: Total Market Demand By Region in 2001.] 21 January 2003.</ref>  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."<ref name=UNEP2007/>

==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.<ref name=UNEP2007/> Elevated concentrations can be found in air, water, soil, food, [[sediment]], [[sludge]], and [[dust]].<ref name=UNEP2007/><ref>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</ref><ref name=Stapleton2004>Stapleton, Heather M., et al. [http://pubs.acs.org/cgi-bin/abstract.cgi/esthag/2005/39/i04/abs/es0486824.html Polybrominated Diphenyl Ethers in House Dust and Clothes Dryer Lint.] ''Environmental Science & Technology'' 39(4), 925-931, 2005.</ref>

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."<ref name=UNEP2007/>

==Exposures and health effects==
OctaBDE may enter the body by ingestion or inhalation.<ref name=ATSDR2004/>  It is "stored mainly in body fat" and may stay in the body for years.<ref name=ATSDR2004/>  In an investigation carried out by the [[World Wide Fund for Nature|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.<ref>WWF Detox Campaign.  [http://assets.panda.org/downloads/badbloodoctober2004.pdf Bad Blood? A Survey of Chemicals in the Blood of European Ministers.] October 2004.</ref>

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."<ref name=ATSDR2004/>

==Governmental actions==
The [[European Union]] has carried out a comprehensive risk assessment under the Existing Substances Regulation 793/93/EEC.<ref name=EU2003/> As a consequence, the EU has banned the use of octaBDE since 2004.<ref name=EU2004>[http://eur-lex.europa.eu/LexUriServ/site/en/oj/2003/l_042/l_04220030215en00450046.pdf 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.</ref>

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."<ref name=EPAWeb>U.S. Environmental Protection Agency. [http://www.epa.gov/oppt/pbde/ Polybrominated diphenylethers (PBDEs).] "Last updated on Thursday, August 2nd, 2007." Accessed 2007-10-26.</ref>  As of mid-2007, a total of eleven states in the U.S. had banned octaBDE.<ref name=NCEL2007>[http://www.ncel.net/newsmanager/news_article.cgi?news_id=175 Maine Joins Washington, Bans PBDEs.] Washington, DC: National Caucus of Environmental Legislators, June 18, 2007.</ref>

It has been proposed that octaBDE be added to the [[Stockholm Convention]] as it meets the criteria for the so-called [[persistent organic pollutant]]s of persistence, [[bioaccumulation]] and [[toxicity]].<ref name=UNEP2007/>

==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."<ref name=RPA2002>Risk & Policy Analysts Limited. [http://www.defra.gov.uk/environment/chemicals/pdf/octa_bdpe_rrs.pdf 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.</ref>

==References==
{{Reflist | 2}}

[[Category:Flame retardants]]
[[Category:Organobromides]]
[[Category:Phenol ethers]]

[[de:Octabromdiphenylether]]
[[Category:2Fix]]