Current Intelligence Bulletin 53. Toluene Diisocyanate (TDI) and Toluenediamine (TDA): Evidence of Carcinogenicity

摘要

Experimental studies in animals have demonstrated that toluene diisocyanate (TDI) is a carcinogen. When rats and mice were exposed orally to commercial-grade TDI (an 80:20 mixture of 2,4- and 2,6-TDI), tumors were induced in both species. The systemic nature of TDI carcinogenicity was demonstrated by the appearance of tumors at multiple sites (pancreas, liver, skin, mammary glands, and circulatory system). Although not statistically significant, rare brain tumors were found in rats exposed to TDI (two gliomas and one pinealoma). Historical controls have a low incident of gliomas and no reported incidence of pinealomas. Experimental studies in animals have also demonstrated that 2,4-toluenediamine (TDA), an hydrolysis product of 2,4-TDI, is a carcinogen. When rats and mice were exposed orally to TDA, tumors were induced in the liver, skin, and mammary glands of both species. The potential for TDI- or TDA-induced cancer in humans has not been determined, but the risk of developing cancer should be decreased by reducing exposure to TDI and TDA in the workplace.