Toxicology of octabromobiphenyl and decabromodiphenyl oxide.

Decabromodiphenyl oxide (DBDPO) and octabromobiphenyl (OBBP) perform well as fire-retardant additives for thermoplastics. Both compounds have low acute oral toxicity and low skin absorption toxicity. They are neither primary skin irritants or skin sensitizers and are only mildly irritating to the eyes. A 30-day dietary feeding study in rats established 8 mg DBDPO/kg-day as an unequivocal no-effect level and 80 mg/kg-day as a marginal effect level. A no-effect level was not established for OBBP in a comparative study. A 2-yr rat study providing 0.1 mg DBDPO/kg-day in the diet revealed the bromine concentration reached a plateau in the liver within 30 days, while the concentration in adipose tissue slowly increased. A comparable OBBP study revealed bromine concentration in the liver and adipose tissue increased steadily and rapidly with no attainment of a plateau during 180 days of the study. Neither compound produced an accumulation of bromine in other tissues. After administration of 14C DBDPO, all 14C ac...