Brominated flame retardant chemicals PBDEs

The replacement of established chemistries with newer ones is one of the classic drivers of change in the chemical industry. One of the current hotbeds of this kind of change is the replacement of brominated flame retardants in polymer formulations. The brominated flame retardants under the most scrutiny have been polybrominated diphenyl ethers, particularly penta- and octabromodiphenyl ether, which have been shown to be persistent in the environment and to bioaccumulate. Great Lakes Chemical is voluntarily phasing out penta- and octa-BDEs by the end of next year. The phaseout is made possible by the clean bill of health granted by EPA for Firemaster 550, a replacement for penta-BDE in flexible PU applications. BRG Townsend claims the phaseout of penta-BDE and octa-BDE is not as earth shattering as would be an exit from deca-BDE, a styrenics additive that is produced in the highest volume of the PBDEs. 

In addition to OCs, PBDEs, the popular brominated flame retardants, are now a worldwide problem even in remote areas, and Asia-Pacific region is surely no exception (Ikonomou et al., 2002 Birnbaum and Staskal, 2004 Ueno et al., 2004). PBDEs are structurally similar to PCBs and DDT and, therefore, their chemical properties, persistence and distribution in the environment follow similar patterns. Studies on the environmental behavior of PBDEs are chiefly derived from Europe, North America and the Arctic. Despite the usage of vast amounts of these compounds in Asia-Pacific region, there is a paucity of data on the prevalence of PBDEs in Asian environment. Studies are necessary to identify Asian sources of PBDEs as well as to quantify emissions and document their potential environmental fate in this region. 

Both HBCD and PBDEs are examples of brominated flame retardants (BFRs). The recent growth in the number of scientific papers addressing the environmental presence and impacts of such chemicals has been quite phenomenonal. In a similar vein, there has been a dramatic rise in concerns related to the environmental presence and impacts of perfluorinated chemicals (PFCs). Chapters 2 and 3 thus address current knowledge and research... 

The saga of brominated flame retardants offers a cautionary tale for the chemical industry.65 These chemicals, developed in the early 1970s, are used in a wide range of consumer products, such as furniture, foam, and plastic casings of electronic devices. In 1998, Swedish scientists reviewing archived human breast milk samples discovered that certain flame retardant chemicals (polybrominated diphenyl ethers, or PBDEs) had doubled in concentration in Swedish breast milk about every five years over the preceding twenty. This was a source of concern, as studies of laboratory animals had shown that PBDEs dismpt thyroid hormones. Such dismption yields neurobehavioral effects similar to those of PCBs (polychlorinated biphenyls), whose manufacture the United States banned in 1976. 

Another MS/MS application for ion trap mass spectrometry involves the analysis of polybrominated flame retardants (PBDEs). As a result of regulations promulgated during the past flve years, such as the Restriction of Hazardous Substances (RoHS) [61] and other similar programs, there has been a determined effort to decrease the use of brominated flame retardants in the manufacture of consumer products. The chemical structure for a typical PBDE is illustrated in Eigure 15.42. 

RoHS Since the Directive on the restriction of the use of certain hazardous substances in electrical and electronic eqnipment (cotmnonly referred to as the Restriction of Hazardous Substances directive of the RoHS directive) came into force in the European Union (EU) in Jnly 2006 [167]. Some of the same regulations on chemical management have been adopted in other parts of the world. The RoHS directive restricts the amount of PBBs and PBDEs [168] contained in electrical and electronic equipment to less than 1000 ppm. No electronic electric apparatus can be marketed in an EU member state if it contains those materials in excess of a designated value of RoHS. PBBs and PBDEs are among the large variety of brominated flame retardants (BFRs) used in plastics and textiles. PBBs are no longer produced, but PBDEs were in widespread nse before the RoHS directive came into effect, and... 

Many brominated flame retardants (BFRs) are persistent and bioaccumulative chemicals that are now present throughout the environment. Polybrominated diphenyl ethers (PBDEs) are one of the most common groups of BFRs and have been used to fireproof a wide variety of materials, including textiles. Some PBDEs are capable of interfering with the hormone systems involved in growth and sexual development. Under EU law, the use of some types... 

One of the main concerns with plastic resin pellets is that they carry persistent organic pollutants (POPs). POPs are human-made chemicals used in a variety of anthropogenic activities, including industry, agriculture and daily life. POPs include polychlorinated biphenyls (PCBs), different sorts of organochloiine pesticides (e.g. DDTs and HCHs) and brominated flame retardants (polybrominated diphenyl ethers, or PBDEs). Because of their very slow rate of degradation, POPs are persistent in the environment. POPs are... 

Eor almost 40 years, the brominated flame retardants (BERs) polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDs), and tetrabro-mobisphenol-A (TBBPA) have been widely used as additive or reactive flame retardants (ERs) in household products and food packaging to meet flammability standards. These chemicals are now recognized as global contaminants and are associated with adverse health effects in animals and humans. 

HBCD is a brominated aliphatic cyclic hydrocarbon used as a flame retardant in thermal insulation building materials, upholstery textiles, and electronics. In 2001, the world market demand for HBCD was 16,700 tons, from which 9,500 tons was sold in the EU. These figures make HBCD the second highest volume BFR used in Europe [29], HBCD may be used as an alternative for PBDEs in some applications. To date, there are no restrictions on the production or use of HBCD. As a result of their widespread use and their physical and chemical properties, HBCD are now ubiquitous contaminants in the environment and humans [30, 31]. 

The PBDEs (decaBDE, octaBDE, and pentaBDE) and are used as flame retardants in plastics, electronic equipment, printed circuit boards, vehicles, furniture, textiles, carpets, and building materials. Global demand has increased rapidly since the 1970s with 70,000 tonnes produced in 2001. Their flame retardant activity relies on decomposition at high temperatures, leading to the release of bromine atoms. This slows the chemical reactions that drive 02-dependent fires. HBCDs are a flame retardant added to extruded and expanded polystyrene that is used as thermal insulation in buildings. 

PBBs and PBDEs belong to a group of brominated organic compounds which are used as flame retardants. Flame retardants are valued for their ability to inhibit combustion in plastics, textiles, electric, and other materials. There are different groups of flame retardants inorganic and organic chemicals. Usually they are divided into reactive and additive flame retardants. 

PBDEs are a class of 209 chemicals that are distinguished by the average number and arrangement of bromine atoms in the molecule—ranging from one bromine atom (monobromodiphenyl ether or monoBDE) to ten bromine atoms (decabromodiphenyl ether or decaBDE). Until recently, the PBDE flame retardant formulations on the market were pentaBDE (five bromine atoms), octaBDE (eight bromine atoms), and decaBDE. PentaBDE and octaBDE were voluntarily removed from the market in 2003 (pentaBDE) and 2004 (octaBDE) by the manufacturer, Chemtura (formerly Great Lakes Chemical), when it became clear that these chemicals were targeted for elimination in Europe and certain states in the US. 

With the 2005 phase-out of PBDEs, many other brominated, chlorinated, and organophosphate flame retardants (OPFRs) have been introduced as replacement FRs (USEPA 2005). Little is known about the composition, uses, human exposure levels and health effects of these chemicals now in everyday use. Of special concern are the replacement chemicals for PentaBDE, particularly tris (1,3-dichloro-2-propyl) phosphate (TDCPP or chlorinated Tris) and Firemaster 550 (FM 550) which contains two brominated components and some additional organophosphate OPFRs (Stapleton et al. 2011, 2012). TDCPP and FM 550 components were the most common FRs detected in PUF foam in U.S. couches purchased after 2005 and baby products such as changing pads and nursing pillows, suggesting that TDCPP and FM 550 are among the highest-volume FRs in households today. 

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