Genetic effects of 2-methoxyethanol and bis(2-methoxyethyl)ether.

2-Methoxyethanol and bis(2-methoxyethyl)ether were subjected to the following assays for genetic toxicity: Ames' test, unscheduled DNA synthesis (UDS) assay in human embryo fibroblasts, sex-linked recessive lethal (SLRL) test in Drosophila, dominant lethal test in male rats, bone marrow metaphase analysis in male and female rats, and the sperm abnormality test in mice. In vivo test animals were exposed to atmospheric concentrations of 25 or 500 ppm 2-methoxyethanol and 250 or 1000 ppm bis(2-methoxyethyl)ether. Point mutations in Ames' test and UDS in fibroblasts were not increased by either compound, while the SLRL test gave ambiguous results which deserve further investigation. Chromosomal aberration frequencies were not increased in rat bone marrow, but there was evidence from the dominant lethal tests that both compounds have profound effects upon male rat fertility during the meiotic phase. Pregnancy frequency was greatly reduced and preimplantation losses were large. In addition, there was evidence of postimplantation losses. Sperm abnormalities were increased in mice exposed to both compounds, but particularly bis(2-methoxyethyl)ether. These effects on male reproductive cells were confined to the higher concentrations of both compounds. It was concluded that the weak mutagenic and particularly the strong antifertility effects described here are important for the safety evaluation of these ethylene glycol ethers.