What is "polybrominated biphenyl"

n. (context chemistry English) Any of a class of stable organic compounds obtained by the bromination of biphenyl; they have many industrial applications, but are hazardous pollutants

Polybrominated biphenyls (PBBs), also called brominated biphenyls or polybromobiphenyls, are a group of manufactured chemicals that consist of polyhalogenated derivatives of a biphenyl core. Their chlorine analogs are the PCBs. While once widely used commercially, PBBs are now controlled substances under the Restriction of Hazardous Substances Directive, which limits their use in electrical and electronic products sold in the EU.