REFERENCE METHOD       US EPA Method 1614, August 2003 Draft

 

Polybrominated diphenyl ethers (PBDEs), widely used flame retardants, have become an increasing concern to scientists and regulatory agencies, because of ubiquitous detection in the environment and bioaccumulation in humans, wildlife and aquatic organisms.  PBDEs are additive (non-covalently bound) flame retardants in polymers and textiles at levels ranging 5% to 30% PBDEs by weight. These compounds can be released into the environment during production and use and from the final treated products during their use and after disposal, thus their appearance in the environment is not surprising.  Commercial PBDE products contain a limited number of PBDE congeners even though as many as 209 congeners may be formed theoretically. The world production of PBDEs have stayed approximately the same for the last decade, but there has been a shift towards the use of highly brominated congeners.  Three commercial formulations of PBDEs, penta-BDE, octa-BDE and deca-BDE, are produced for use exclusively as flame retardants. Each formulation consists of a mix of PBDE homologues with different bromination patterns and different physiochemical properties. Deca-BDE accounts for 75% of PBDE production, but the congener profile commonly found in biota is often similar to the penta-BDE commercial product, a mix of tetra-, penta- and some hexa-BDE.  Research suggests this biotic congener profile results from a preferential uptake of lower brominated compounds.