2,2',3,3',4,5'-Hexabromodiphenyl ether

EYES: irrigate opened eyes for several minutes under running water. INGESTION: do not induce vomiting. Rinse mouth with water (never give anything by mouth to an unconscious person). Seek immediate medical advice. SKIN: should be treated immediately by rinsing the affected parts in cold running water for at least 15 minutes, followed by thorough washing with soap and water. If necessary, the person should shower and change contaminated clothing and shoes, and then must seek medical attention. INHALATION: supply fresh air. If required provide artificial respiration.

Like other halogenated aromatic hydrocarbons, polybrominated diphenyl ethers bind to the cellular aryl hydrocarbon receptor (AhR), which regulates the synthesis of a variety of proteins. Activation of the AhR induces a number of enzymes, including cytochrome P-450-dependent monooxygenases of the CYP1A and CYP2B families, UDP-glucuronosyltransferase, and ethoxyresorufin-o-deethylase. PBDEs are also believed to disrupt the production, transport, and disposition of thyroid hormones. One mechanism of this involves metabolites ot PDBEs competing with thyroxine to bind to transthyretin, decreasing serum thyroid hormone levels. This change in thyroid hormone levels has been linked to both thyroid toxicity and neurobehavioral alterations. Certain PDBEs and their metabolites are also endocrine disruptors and may act as agonists at the estrogen receptors or antagonists at the androgen and progesterone receptors. (L628, A262)

Polybrominated biphenyls can be absorbed through oral, inhalation, and dermal routes. Once in the body they distribute throughout and bioaccumulate in the blood, breast milk, and adipose tissue. The extent of PBDE metabolism depends on the degree of bromination. Metabolism is believed to involve debromination and methylation, resulting in phenolic metabolites. Metabolized and unmetabolized PDBE compounds are excreted mainly in the faeces. (L628, L881)

Polybrominated diphenyl ethers (PBDEs) are flame-retardant chemicals found in plastics used in a variety of consumer products to make them difficult to burn. Because they are mixed into plastics and foams rather than bound to them, PBDEs can leave the products that contain them and enter the environment. (L628)