POLYCHLORINATED BIPHENYLS (PCBs)

Comments:

PCBs include 50-60 different congeners of varying degrees of chlorination. Ingestion of the less-chlorinated congeners results in hydroxylation of these compounds in the liver. The highly-chlorinated congeners are metabolically-inert, and ingestion of these congeners results in accumulation of the parent compound in body fat. Based on the available toxicological database, the Committee concluded that the monkey was the most appropriate animal model for use in risk assessment and chose the NOEL of 0.04 mg/kg bw/d from a feeding study in monkeys as the point of departure. Due to the limitations of the available data, especially the ill-defined nature of the test materials used in the toxicity studies, the Committee did not establish a tolerable intake value for PCBs. However, from comparison of the 0.04 mg/kg bw/d NOEL value to the estimated dietary intake values of 0.005-2 μg/kg bw/d (adults) and 2-12 μg/kg bw/d (breast-fed infants), the Committee concluded that consumption of PCBs at the current levels in the diet did not indicate a long-term health hazard. The Committee recommended that PCB intake be kept as low as possible and that PCB levels in the diet be reduced to a minimum.

Intake:

Median dietary intake estimates: 0.005-2 μg/kg bw/d (adults), 2-12 μg/kg bw/d (breast-fed infants). Estimates depended upon the food types included and the method used to estimate PCB intake.

Tolerable Intake:

NOT ESTABLISHED

Meeting:

35

Report: 

Tox Monograph: