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Octabromodiphenyl ether (octaBDE, octa-BDE, OBDE, octa, octabromodiphenyl oxide, OBDPO) is a
brominated flame retardant Brominated flame retardants (BFRs) are organobromine compounds that have an inhibitory effect on combustion chemistry and tend to reduce the flammability of products containing them. The brominated variety of commercialized chemical flame retardants ...
which belongs to the group of
polybrominated diphenyl ether Polybrominated diphenyl ethers or PBDEs, are a class of organobromine compounds that are used as flame retardants. Like other brominated flame retardants, PBDEs have been used in a wide array of products, including building materials, electronics, ...
s (PBDEs).


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.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.
The predominant congeners in commercial octaBDE are those of heptabromodiphenyl ether and octaBDE.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.
The term octaBDE alone refers to
isomer In chemistry, isomers are molecules or polyatomic ions with identical molecular formulae – that is, same number of atoms of each element – but distinct arrangements of atoms in space. Isomerism is existence or possibility of isomers. Iso ...
s of octabromodiphenyl ether (PBDE congener numbers 194–205).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.
Only congeners with more than 1% listed. OctaBDE is used in conjunction with
antimony trioxide Antimony(III) oxide is the inorganic compound with the formula Sb2O3. It is the most important commercial compound of antimony. It is found in nature as the minerals valentinite and senarmontite. Like most polymeric oxides, Sb2O3 dissolves in a ...
as a flame retardant in the housings of electrical and electronic equipment, mainly in the plastic
acrylonitrile butadiene styrene Acrylonitrile butadiene styrene (ABS) (chemical formula (C8H8)''x''·(C4H6)''y''·(C3H3N)''z'' is a common thermoplastic polymer. Its glass transition temperature is approximately . ABS is amorphous and therefore has no true melting point. A ...
, but also in
high impact polystyrene Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a ...
,
polybutylene terephthalate Polybutylene terephthalate (PBT) is a thermoplastic engineering polymer that is used as an insulator in the electrical and electronics industries. It is a thermoplastic (semi-)crystalline polymer, and a type of polyester. PBT resists solvents, s ...
and
polyamide A polyamide is a polymer with repeating units linked by amide bonds. Polyamides occur both naturally and artificially. Examples of naturally occurring polyamides are proteins, such as wool and silk. Artificially made polyamides can be made through ...
s.European Union risk assessment report. Diphenyl ether, octabromo derivative.
Luxembourg: Office for Official Publications of the European Communities, 2003. Publication EUR 20403 EN.
Typically 12–15% of the weight of the final product will consist of octaBDE. The annual demand worldwide was estimated as 3,790
tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000  kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...
s in 2001, of which Asia accounted for 1,500 tonnes, the Americas 1,500 tonnes, and Europe 610 tonnes. The
United Nations Environment Programme The United Nations Environment Programme (UNEP) is responsible for coordinating responses to environmental issues within the United Nations system. It was established by Maurice Strong, its first director, after the United Nations Conference on th ...
reports "Since 2004, it ctaBDEis 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."


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. Elevated concentrations can be found in air, water, soil, food,
sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...
,
sludge Sludge is a semi-solid slurry that can be produced from a range of industrial processes, from water treatment, wastewater treatment or on-site sanitation systems. For example, it can be produced as a settled suspension obtained from conventiona ...
, and
dust Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in homes ...
.Stapleton, Heather M., et al
Polybrominated Diphenyl Ethers in House Dust and Clothes Dryer Lint.
''Environmental Science & Technology'' 39(4), 925-931, 2005.
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."


Exposures and health effects

OctaBDE may enter the body by ingestion or inhalation. It is "stored mainly in body fat" and may stay in the body for years. 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.WWF Detox Campaign.
Bad Blood? A Survey of Chemicals in the Blood of European Ministers.
October 2004.
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."


Governmental actions

The
European Union The European Union (EU) is a supranational political and economic union of member states that are located primarily in Europe. The union has a total area of and an estimated total population of about 447million. The EU has often been des ...
has carried out a comprehensive risk assessment under the Existing Substances Regulation 793/93/EEC. As a consequence, the EU has banned the use of octaBDE since 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.
In the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
, as of 2005, "no new manufacture or import of" pentaBDE and octaBDE "can occur... without first being subject to EPA .e.,_United_States_Environmental_Protection_Agency_.html" ;"title="United States Environmental Protection Agency">.e., United States Environmental Protection Agency ">United States Environmental Protection Agency">.e., United States Environmental Protection Agency evaluation."U.S. Environmental Protection Agency
Polybrominated diphenylethers (PBDEs).
"Last updated on Thursday, August 2nd, 2007." Accessed 2007-10-26.
As of mid-2007, a total of eleven states in the U.S. had banned octaBDE.Maine Joins Washington, Bans PBDEs.
Washington, DC: National Caucus of Environmental Legislators, June 18, 2007.
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

Alternatives to octaBDE include
tetrabromobisphenol A Tetrabromobisphenol A (TBBPA) is a brominated flame retardant. The compound is a white solid (not colorless), although commercial samples appear yellow. It is one of the most common flame retardants. Production and use TBBPA is produced by the ...
, 1,2-bis (pentabromophenoxy) ethane, 1,2-bis(tribromophenoxy)ethane,
triphenyl phosphate Triphenyl phosphate (TPhP) is the chemical compound with the Chemical formula, formula OP(OC6H5)3. This colourless solid is the ester (triester) of phosphoric acid and phenol. It is used as a plasticizer and a fire retardant in a wide variety of s ...
, 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."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.


References

{{Reflist , 2 Flame retardants Bromoarenes Phenol ethers