Final Report on the Safety Assessment of Dibutyl Adipate

Abstract

The diester Dibutyl Adipate functions as a plasticizer and skin-conditioning agent in cosmetic formulations, although it is reportedly used in only one such product. Only limited safety test data were available to the Cosmetic Ingredient Review Expert Panel. The oral median lethal dose in rats was 2 g/kg for a 20% suspension of Dibutyl Adipate. Subchronic dermal exposure of rabbits to 1.0 ml/kg/day caused a reduction in weight gain, which was not seen at 0.5 ml/kg/day. Undiluted Dibutyl Adipate caused mild to moderate skin irritation in rabbits, but it was minimally irritating to the eyes. The fetuses of pregnant rats given intraperitoneal injections of 1.748 ml/kg on days 5, 10, and 15 of gestation showed significant increases in the incidence of gross abnormalities. No effect was seen at lower exposures. The following additional safety test data are needed: (1) the typical concentration at which this ingredient is used, (2) the types of products in which it is found, (3) impurities that may be present in Dibutyl Adipate in cosmetic formulations, (4) ultraviolet radiation absorption data (if there is significant UV absorption, photosensitization data may be needed), and (5) two genotoxicity studies, one using a mammalian system. If these latter studies are positive, a dermal carcinogenesis study using the methods of the National Toxicology Program may be needed. In the absence of this further information, the available data are insufficient to support the safety of Dibutyl Adipate in cosmetics.