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IPEN Body Burden Community Monitoring Handbook Fire RetardantPolybrominated diphenyl ethers (PBDEs) Chemical Name: Polybrominated diphenyl ethers (C12H(10-n)BrnO, where n = 1-10). As in the case of PCBs the total number of congeners is 209, with a predominance in commercial mixtures of the tetra-, penta- and octa-substituted isomers. CAS Number: Properties: Solubility in water: mg/L at 25°C; vapour pressure: 3.85 up to 13.3 x 10 -3 mmHg at 20-25 °C; log KOW: 4.28 - 9.9. Discovery/Uses: Since the 1960s, three commercial PBDE formulations are in production. The pentabrominated product is used principally to flame retard polyurethane foams in furniture, carpet underlay and bedding. Commercial octa is a mixture of hexa- (10-12%), hepta- (44-46%), octa- (33-35%) and nonabromodiphenyl (10-11%) ethers. It is used to flame retard a wide variety of thermoplastics and is recommended for injection moulding applications such as high impact polystyrene (HIPS). The deca product (a single congener) is used predominantly for textiles and denser plastics such as housings for a variety of electrical products in particular TVs and computers. Persistence/Fate: Data on environmental fate, although limited, suggest that biodegradation is not an important degradation pathway, but that photodegradation may play a significant role. They have already been found in high concentrations in marine birds and mammals from remote areas. The half-lives of PBDE components in rat adipose tissue vary between 19 and 119 days, the higher values being for the higher brominated congeners. Toxicity: The available data suggest that the lower (tetra- to hexa-) PBDE congeners are likely to be carcinogens, endocrine disruptors, and/or neurodevelopmental toxicants. Studies in rats with commercial PeBDE indicate a low acute toxicity via oral and dermal routes of exposure, with LD50 values > 2000 mg/kg bw. In a 30-day study with rats, effects on the liver could be seen at a dose of 2 mg/kg bw/day, with a NOEL at 1mg/kg bw/day. The toxicity to Daphnia magna has also been investigated and and LC50 was found to be 14 µg/L with a NOEC of 4.9 µg/L. Although data on toxicology is limited, they have potential endocrine disrupting properties, and there are concerns over the health effects of exposure. Source: UNEP Chemicals, Regional Reports of the Regionally Based Assessment of Persistent Toxic Substances Program (2002) Available from: http://www.chem.unep.ch/pts UNEP Chemicals 11-13, chemin des Anemones CH-1219 Chatelaine, GE Switzerland. 
IPEN Body Burden Community Monitoring Handbook - 2003 |
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