Musk xylene (CAS no. 81-15-2), a synthetic musk fragrance ingredient,
was evaluated in a battery of short-term genotoxicity tests that inclu
ded the mouse lymphoma assay, an in vitro cytogenetics assay in Chines
e hamster ovary (CHO) cells, the in vitro unscheduled DNA synthesis (U
DS) assay in primary rat hepatocytes and an in vivo UDS assay. Musk xy
lene gave uniformly negative results in these genotoxicity tests. Thes
e observations, combined with previously reported negative Ames tests,
suggest a non-genotoxic mechanism for the induction of mouse liver tu
mours by musk xylene.