Pentabromodiphenyl ether
Encyclopedia
Pentabromodiphenyl ether (also known as pentabromodiphenyl oxide) is a brominated flame retardant which belongs to the group of polybrominated diphenyl ethers (PBDEs). Because of their toxicity and persistence, their industrial production is to be eliminated under the Stockholm Convention
, a treaty to control and phase out major persistent organic pollutants (POP).
s, with BDE-47 (2,2',4,4'- tetrabromodiphenyl ether) and BDE-99 (2,2',4,4',5-pentabromodiphenyl ether, pictured in the Infobox) as the most abundant. The term pentaBDE alone refers to isomer
s of pentabromodiphenyl ether (PBDE congener numbers 82-127).
Only congeners with more than 1 % listed.
Commercial pentaBDE is most commonly used as a flame retardant in flexible polyurethane
foam; it was also used in printed circuit board
s in Asia, and in other applications. The annual demand worldwide was estimated as 7,500 tonne
s in 2001, of which the Americas accounted for 7,100 tonnes, Europe 150 tonnes, and Asia 150 tonnes. The global industrial demand increased from 4,000 tonnes annually in 1991 to 8,500 tonnes annually in 1999. As of 2007, "there should be no current production of C-PentaBDE [commercial pentaBDE] in Europe, Japan, Canada, Australia and the US"; however, it is possible that production continues elsewhere in the world.
, sludge
, and dust
.
factors in terrestrial carnivores and humans of 98, higher than any other industrial chemicals studied. 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.
The chemical has no proven health effects in humans; however, based on animal experiments, pentaBDE may have effects on "the liver, thyroid, and neurobehavioral development."
, industrial users of pentaBDE "agreed to a voluntary phaseout in 1986." In Sweden
, the government "phase[d] out the production and use of the [pentaBDE] compounds by 1999 and a total ban on imports came into effect within just a few years." The European Union
(EU) 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 pentaBDE since 2004.
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." As of mid-2007, a total of eleven states in the U.S. had banned pentaBDE.
It has been proposed that pentaBDE be added to the Stockholm Convention
as it meets the criteria for the so-called persistent organic pollutant
s of persistence, bioaccumulation
and toxicity
.
, tribromoneopentyl alcohol, tris(1,3-dicholoro-2-propyl)phosphate, and 12 proprietary chemicals.
Stockholm Convention on Persistent Organic Pollutants
Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed in 2001 and effective from May 2004, that aims to eliminate or restrict the production and use of persistent organic pollutants .- History :...
, a treaty to control and phase out major persistent organic pollutants (POP).
Composition, uses, and production
Commercial pentaBDE is a technical mixture of different PBDE congenerCongener
Congener has several different meanings depending on the field in which it is used. Colloquially, it is used to mean a person or thing like another, in character or action.-Biology:In biology, congeners are organisms within the same genus...
s, with BDE-47 (2,2',4,4'- tetrabromodiphenyl ether) and BDE-99 (2,2',4,4',5-pentabromodiphenyl ether, pictured in the Infobox) as the most abundant. The term pentaBDE alone refers to isomer
Isomer
In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...
s of pentabromodiphenyl ether (PBDE congener numbers 82-127).
| Structure | Congener | Name | Fraction |
|---|---|---|---|
| BDE-47 | 2,2′,4,4′-tetra- bromodiphenyl ether |
38–42 % | |
| BDE-85 | 2,2′,3,4,4′-penta- bromodiphenyl ether |
2.2–3.0 % | |
| BDE-99 | 2,2′,4,4′,5-penta- bromodiphenyl ether |
45–49 % | |
| BDE-100 | 2,2′,4,4′,6-penta- bromodiphenyl ether |
7.8–13 % | |
| BDE-153 | 2,2′,4,4′,5,5′-hexa- bromodiphenyl ether |
5.3–5.4 % | |
| BDE-154 | 2,2′,4,4′,5,6′-hexa- bromodiphenyl ether |
2.7–4.5 % |
Only congeners with more than 1 % listed.
Commercial pentaBDE is most commonly used as a flame retardant in flexible polyurethane
Polyurethane
A polyurethane is any polymer composed of a chain of organic units joined by carbamate links. Polyurethane polymers are formed through step-growth polymerization, by reacting a monomer with another monomer in the presence of a catalyst.Polyurethanes are...
foam; it was also used in printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...
s in Asia, and in other applications. The annual demand worldwide was estimated as 7,500 tonne
Tonne
The tonne, known as the metric ton in the US , often put pleonastically as "metric tonne" to avoid confusion with ton, is a metric system unit of mass equal to 1000 kilograms. The tonne is not an International System of Units unit, but is accepted for use with the SI...
s in 2001, of which the Americas accounted for 7,100 tonnes, Europe 150 tonnes, and Asia 150 tonnes. The global industrial demand increased from 4,000 tonnes annually in 1991 to 8,500 tonnes annually in 1999. As of 2007, "there should be no current production of C-PentaBDE [commercial pentaBDE] in Europe, Japan, Canada, Australia and the US"; however, it is possible that production continues elsewhere in the world.
Environmental chemistry
PentaBDE is released by different processes into the environment, such as emissions from manufacture of pentaBDE-containing products and from the products themselves. Elevated concentrations can be found in air, water, soil, food, sedimentSediment
Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....
, sludge
Sludge
Sludge refers to the residual, semi-solid material left from industrial wastewater, or sewage treatment processes. It can also refer to the settled suspension obtained from conventional drinking water treatment, and numerous other industrial processes...
, and dust
Dust
Dust consists of particles in the atmosphere that arise from various sources such as soil dust lifted up by wind , volcanic eruptions, and pollution...
.
Exposures and health effects
PentaBDE may enter the body by ingestion or inhalation. It is "stored mainly in body fat" and may stay in the body for years. A 2007 study found that PBDE 47 (a tetraBDE) and PBDE 99 (a pentaBDE) had biomagnificationBiomagnification
Biomagnification, also known as bioamplification or biological magnification, is the increase in concentration of a substance that occurs in a food chain as a consequence of:* Persistence...
factors in terrestrial carnivores and humans of 98, higher than any other industrial chemicals studied. In an investigation carried out by the WWF
World Wide Fund for Nature
The World Wide Fund for Nature is an international non-governmental organization working on issues regarding the conservation, research and restoration of the environment, formerly named the World Wildlife Fund, which remains its official name in Canada and the United States...
, "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.
The chemical has no proven health effects in humans; however, based on animal experiments, pentaBDE may have effects on "the liver, thyroid, and neurobehavioral development."
Voluntary and governmental actions
In GermanyGermany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, industrial users of pentaBDE "agreed to a voluntary phaseout in 1986." In Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
, the government "phase[d] out the production and use of the [pentaBDE] compounds by 1999 and a total ban on imports came into effect within just a few years." The European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
(EU) 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 pentaBDE since 2004.
In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, 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
United States Environmental Protection Agency
The U.S. Environmental Protection Agency is an agency of the federal government of the United States charged with protecting human health and the environment, by writing and enforcing regulations based on laws passed by Congress...
] evaluation." As of mid-2007, a total of eleven states in the U.S. had banned pentaBDE.
It has been proposed that pentaBDE be added to the Stockholm Convention
Stockholm Convention
Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed in 2001 and effective from May 2004, that aims to eliminate or restrict the production and use of persistent organic pollutants .- History :...
as it meets the criteria for the so-called persistent organic pollutant
Persistent organic pollutant
thumb|right|275px|State parties to the Stockholm Convention on Persistent Organic PollutantsPersistent organic pollutants are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes...
s of persistence, bioaccumulation
Bioaccumulation
Bioaccumulation refers to the accumulation of substances, such as pesticides, or other organic chemicals in an organism. Bioaccumulation occurs when an organism absorbs a toxic substance at a rate greater than that at which the substance is lost...
and toxicity
Toxicity
Toxicity is the degree to which a substance can damage a living or non-living organisms. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell or an organ , such as the liver...
.
Alternatives
The EPA organized a Furniture Flame Retardancy Partnership beginning in 2003 "to better understand fire safety options for the furniture industry" after pentaBDE "was voluntarily phased out of production by the sole U.S. manufacturer on December 31, 2004." In 2005 the Partnership published evaluations of alternatives to pentaBDE, including triphenyl phosphateTriphenyl phosphate
Triphenyl phosphate is the chemical compound with the formula OP3. This colourless solid is the ester of phosphoric acid and phenol. It is used as a plasticizer and a fire retardant....
, tribromoneopentyl alcohol, tris(1,3-dicholoro-2-propyl)phosphate, and 12 proprietary chemicals.