Polybrominated diphenyl ethers
801852
225358596
2008-07-13T07:35:10Z
SmackBot
433328
Date the maintenance tags or general fixes
'''Polybrominated diphenyl ethers''' or '''PBDE''', are a [[flame retardant]] sub-family of the [[brominated flame retardant]] group. They have been used in a wide array of household products, including fabrics, furniture, and electronics. Polybrominated diphenylethers represent a class of flame retardant chemicals akin to that of PCB’s in their functionality, however there much debate about the potential health affects surrounding this recently synthesized chemical. Polybrominated diphenylethers, abbreviated as PBDEs, operate as a specific group of flame retardant chemicals commonly utilized as constituents in building materials, electronics, furnishings, motor vehicles, plastics, polyurethane foams, and textiles. There are three main types, referred to as penta, octa and deca for the number of [[bromine]] atoms in the molecule. After studies in [[Sweden]] found substances related to PentaBDE accumulating in breast milk and other tissues, Sweden reduced the use of this substance. A follow-up study has in the meantime indicated declining levels.<ref>{{cite journal |author=Lind Y, Darnerud PO, Atuma S, ''et al'' |title=Polybrominated diphenyl ethers in breast milk from Uppsala County, Sweden |journal=[[Environ. Res.]] |volume=93 |issue=2 |pages=186–94 |year=2003 |month=October |pmid=12963403 |doi= 10.1016/S0013-9351(03)00049-5 }}</ref>
The [[European Union]] has carried out a comprehensive risk assessment under the Existing Substances Regulation 793/93/EEC of [[Pentabromodiphenyl ether|Penta-]], [[Octabromodiphenyl ether|Octa-]] and [[Decabromodiphenyl ether|DecaBDE]]. As a consequence the EU banned the use of penta-and octaBDE in 2004 and deca-BDE in 2008.<ref>{{cite journal | author = Kellyn S. Betts | url = http://www.ehponline.org/members/2008/116-5/innovations.html | title = New Thinking on Flame Retardants | format = Open Access | journal = [[Environmental Health Perspectives]] | volume = 116 | issue = 5 | pages = A211–213 | year = 2008}}</ref>
An experiment conducted at [[Woods Hole Oceanographic Institution]] in 2005 showed that the [[isotopic signature]] of methoxy-PBDEs found in [[whale]] [[blubber]] contained [[carbon-14]], the naturally occurring radioactive [[isotope]] of carbon. Methoxy-PBDEs are produced by some marine species.<ref>{{cite journal | author = A. Malmvärn, Y. Zebühr, L. Kautsky, Å. Bergman, L. Asplund | title = Hydroxylated and methoxylated polybrominated diphenyl ethers and Polybrominated dibenzo-p-dioxins in red alga and cyanobacteria living in the Baltic Sea | journal = [[Chemosphere (journal)|Chemosphere]] | volume = 72 | year = 2008 | pages = 910–916 | doi = 10.1016/j.chemosphere.2008.03.036}}<!-- there are so many related publications, feel free to replace this specific ref with a review when one appears--></ref> If the methoxy-PBDEs in the whale had come from artificial (human-made) sources, they would have only contained carbon-12 and no carbon-14 due to the fact that virtually all PBDEs which are produced artificially use petroleum as the source of carbon; all carbon-14 would have long since completely decayed from that source.<ref>{{cite journal | author = Emma L. Teuten, Li Xu, Christopher M. Reddy | year = 2005 | title = Two Abundant Bioaccumulated Halogenated Compounds Are Natural Products | journal = [[Science (journal)|Science]] | volume = 307 | issue = 5711 | pages = 917–920 | doi = 10.1126/science.1106882 | pmid = 15705850}}</ref> The isotopic signatures of the PBDEs themselves were not evaluated. PBDEs have also been found at high levels in indoor dust, sewage sludge and wastewater treatment plant effluents.
== Sub-groups ==
[[Image:Polybrominated diphenyl ether.svg|framed|240px|Chemical structure of PBDEs]]
The family of PBDEs consists of 209 possible substances, which are called [[congeners]] (PBDE = C<sub>12</sub>H<sub>10−x</sub>Br<sub>x</sub>O (x = 1, 2, ..., 10 = m + n)). The 209 possible PBDE congeners are brominated with 2-10 bromine atoms, which attach to one of the two benzene rings of a diphenyl framework. PBDEs are akin to PCBs in that both molecules contain 209 congeners, however the number of PBDE congeners utilized in commerce is a significantly smaller subset compared to the number of PCB congeners utilized industrially. The 209 PBDE congeners are listed in ascending order, adhering to the IUPAC protocols concerning characterization of biphenyl's. PBDE congeners containing the same number of bromines atoms are referred to as a homolog. A PBDE homolog ranges from 2-10 bromines and classifies as follows: dibromodiphenyl ether, tribromodiphenyl ether, tetrabromodiphenyl ether, pentabromodiphenyl ether, hexabromodiphenyl ether, heptabromodiphenyl ether, octabromodiphenyl ether, nonabromodiphenyl ether, and decabromodiphenyl ether. In the United States, corporations offer marketable PBDEs with trade names: DE-60F, DE-61, DE-62, and DE-71 applied to pentaBDE mixtures; DE-79 applied to octaBDE mixtures; DE 83R and Saytex 102E applied to decaBDE mixtures.
Two sub-groups are:
'''Lower brominated PBDEs''' have 1-5 [[bromine]] atoms and are regarded as the more dangerous ones, because they are smaller molecules that can be absorbed by living [[organism]]s. Lower brominated PBDEs have been known to affect [[hormone]] levels in the [[thyroid]] gland. Studies have linked them to reproductive and neurological risks at certain concentrations or higher.<ref name="EST1">{{cite news | publisher = [[Environmental Science & Technology]] | url = http://pubs.acs.org/subscribe/journals/esthag-w/2001/dec/science/kb_pbde.html | author = Kellyn S. Betts | title = Rapidly rising PBDE levels in North America | date = 2001-12-07}}</ref>
'''Higher brominated PBDEs''' have more than 5 [[bromine]] atoms and were formerly regarded as environmentally harmless chemical compounds, but studies by the Swedish Environmental Board have linked them to thin egg shells for [[Peregrine falcon]]s.<ref>{{cite journal |author=Lindberg P, Sellström U, Häggberg L, de Wit CA |title=Higher brominated diphenyl ethers and hexabromocyclododecane found in eggs of peregrine falcons (Falco peregrinus) breeding in Sweden |journal=[[Environ. Sci. Technol.]] |volume=38 |issue=1 |pages=93–6 |year=2004 |month=January |pmid=14740722 |doi= |url=}}</ref>
The available commercial PBDE products are not purely uniform substances composed of one single congener but rather are composed of a mixture of PBDE congeners. The commercial mixture, named pentabromodiphenyl ether, contains the pentabromo derivative predominantly (50-62%), however the mixture also contains tetrabromides (24-38%) and hexabromides (4-8%), as well as traces of the tribromides (0-1%). Similarly, commercial octabromodiphenyl ether is a mixture of homologs: hexa-, hepta-, octa-, nona-, and decabromides.
== Health concerns ==
Since 1998, concerns have been raised about the safety of PBDEs after Swedish scientists noticed substances related to PentaBDE were accumulating in human breast milk.<ref>[http://www.sciencenews.org/20031025/bob10.asp Science News Online article] "New PCBs?"</ref> Based on a comprehensive risk assessment under the Existing Substances Regulation 793/93/EEC, the EU has banned the use of Penta- and OctaBDE since 2004.<ref name="EU-Ban">[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]</ref>
Studies in [[Canada]] have found significant concentrations of PBDEs in common food products such as [[salmon]], [[ground beef]], [[butter]], and [[cheese]].<ref>[http://www.theglobeandmail.com/servlet/story/RTGAM.20050214.wchemicals14/BNStory/specialScienceandHealth Globe and Mail article] "Common foods laced with chemical"</ref> In Canada there is no set limit for what upper amount of PBDEs in the [[human body]] is still considered to be safe, but there remains concern in the general public that the PBDEs are having harmful effects on human health and the environment.
Most people are exposed to low-level concentrations of PBDEs through ingestion of food and/or by inhalation. PBDEs bioaccumulate in the human body, including the blood, breast milk, and fat tissues. This bioaccumulation results from exposure to low levels of PBDEs. Personnel associated with the manufacture of PBDE-containing products are exposed to higher levels of PBDEs than the average individual. Bioaccumulation is also associated with personnel in recycling and repairs of products containing PBDEs, especially when working in confining spaces. Symptoms: OctaBDE and pentaBDE exposure effects developmental and nervous system toxicity, disruption of estrogen and thyroid function.{{Fact|date=July 2008}}
Environmental organizations argue that all PBDEs should be banned as they aren’t needed and replacements are available.{{Fact|date=February 2007}} But, the electronics industry claims that PBDEs are applied to most newly manufactured electronic assemblies such as [[printed circuit board]]s and [[capacitor]]s and thus are vital to their business.{{Fact|date=February 2007}}
According to U.S.EPA's Integrated Risk Information System evidence that indicates these chemicals may possess liver toxicity, thyroid toxicity, and neurodevelopmental toxicity.<ref> www.epa.gov/iris</ref>
In August, 2003, the State of California outlawed the sale of penta- and octa- PBDE and products containing them, effective January 1, 2008.<ref name="PBDEban">[http://www.leginfo.ca.gov/pub/03-04/bill/asm/ab_0301-0350/ab_302_bill_20030811_chaptered.html "BILL NUMBER: AB 302, An act to add Chapter 10 (commencing with Section 108920) to Part 3 of Division 104 of the Health and Safety Code, relating to toxic substances."]</ref> In April 2007, the legislature of the state of [[Washington]] passed a bill banning the use of PBDEs.<ref name="PBDEbanWA">[http://seattlepi.nwsource.com/local/311845_pbdes17.html "Chemical ban puts industry on the defensive."] State of Washington bans use of PBDEs.</ref> In May 2007, the legislature of the state of [[Maine]] passed a bill phasing out the use of DecaBDE.<ref name="DecaBDEban">[http://www.nrcm.org/news_detail.asp?news=1568 "Maine Legislature votes to ban toxic Deca flame retardant."] State of Maine bans use of DecaBDE.</ref>
It has been postulated that increasing levels of PBDEs in the environment could be correlated with the increasing incidence of feline hyperthyroidism. However, a study in 2007 found that no association could be detected between hyperthyroid cats and serum PBDE levels.<ref>{{cite journal | doi = 10.1021/es0708159 | title = Elevated PBDE Levels in Pet Cats: Sentinels for Humans? | year = 2007 | author = Dye, J.A. | journal = Environmental Science & Technology | volume = 41 | pages = 6350}}</ref>
== Testing for PBDE in plastics==
Until recently,<!--Please provide specific date range--> testing for PBDE has been cumbersome. Cycle time, inaccuracy, cost and level of expertise required for the test engineer has precluded the implementation of any screening of plastic component in a manufacturing or in a product qualification/validation environment.
Recently, with the introduction of a new analytical instrument [[IA-Mass]], screening of plastic material alongside manufacturing line is possible. A 5 min. detection cycle and a 20 min. quantification cycle is available to test and to qualify plastic parts as they reach the assembly line.
As of June 1, 2006 the State of California began prohibiting the manufacture, distribution, and processing of flame retardant products containing pentabrominated diphenyl ether (pentaBDE) and octabrominated diphenyl (octaBDE). PBDEs are ubiquitous in the environment and according to the EPA exposure may pose health risks.
== References ==
<references/>
== External links ==
* [http://www.oehha.ca.gov/pdf/PBDEWrkgrpRptFeb06.pdf Sandy, Martha. Polybrominated Diphenyl Ethers: Recommendations to Reduce Exposure in California. Office of Environmental Health Hazard Assessment. 25 Apr. 2008 ]
* [http://www.epa.gov/oppt/pbde/ Polybrominated diphenylethers (PBDEs) | Pollution Prevention and Toxics (OPPT) | Prevention, Pesticides and Toxics (OPPTS). U.S. Environmental Protection Agency. 25 Apr 2008]
* [www.atsdr.cdc.gov/toxprofiles/tc6.. Chemical and Physical Information. Toxicology Profiles. 25 Apr. 2008 ]
* [http://pubs.acs.org/subscribe/journals/esthag-w/2001/dec/science/kb_pbde.html Environment and Science T pdf echnology article]
* [http://chemistry.about.com/cs/medical/a/aa102603a.htm About.com article]
* [http://www.ewg.org/reports/mothersmilk Environmental Working Groups] 2003 report of record concentrations of PBDEs in American Mothers
* [http://www.northwestwatch.org/toxics/regional_facts_aug_05.asp Northwest Environment Watch]
* [http://assets.panda.org/downloads/badbloodoctober2004.pdf Survey of chemicals in the blood of European ministers], where PBDEs have been found in all blood samples
* [http://seattlepi.nwsource.com/local/309169_pbde28.html PBDEs: They are everywhere, they accumulate and they spread]
* [http://www.etoxics.org/site/PageServer?pagename=svtc_bfrs_in_electronics Silicon Valley Toxics Coalition: BFRs in Electronics]
* [http://acswebapplications.acs.org/applications/ccs/application/index.cfm?PressReleaseID=2834&categoryid=21 Study links cat disease to flame retardants in furniture and to pet food]
*[http://www.newsroom.ucr.edu/cgi-bin/display.cgi?id=1731 UCR: Chemicals Used as Fire Retardants Could Be Harmful, UCR Researchers Say]
{{HealthIssuesOfPlastics}}
[[Category:Flame retardants]]
[[Category:Organobromides]]
[[Category:Persistent organic pollutants]]
[[cs:Polybromované difenylethery]]
[[de:Polybromierte Diphenylether]]
[[es:PBDE]]
[[fr:Polybromodiphényléther]]
[[nl:PBDE]]
[[ja:ポリ臭化ジフェニルエーテル]]