Risk evaluation of dietary and dermal exposure to musk fragrances

Abstract

Synthetic musk compounds comprising nitro musks, polycyclic musks and macrocyclic musks are used in fragrances which are added to a variety of cosmetic as well non-cosmetic household products. The main source of human exposure to musks is fresh water fish, as a result of water contamination from the sewage plants, and a dermal application of cosmetics. The musks accumulate in human adipose tissue and significant levels are present in breast milk. The most frequently used polycyclic compounds AHTN and HHCB as well as nitro musks musk xylene (MX) and musk ketone (MK) show a low acute and subchronic toxicity and no indication of teratogenicity or reproduction toxicity. The substances do not show a mutagenic potential but MX was found to be tumorigenic in animal experiments probably due to non-genotoxic mechanism based on a significant hepatic cytochrome P450 enzyme induction. The hepatic microsomal enzyme induction activity under the development seen in the animal experiments appears to be the most sensitive toxicological endpoint. The calculation of a tolerable intake based on the data available indicates a good safety margin for the consumers of musk contaminated fish. In comparison, the exposure of infants to MX via breast milk and the dermal exposure to MX and AHTN from the cosmetics may reach the range of estimated safe intake. More toxicological studies as well as data on the occurrence and exposure are needed to enable a reliable risk assessment and management of the synthetic musk compounds after dietary and dermal exposure.