2-(2-methoxyethoxy)ethanol

Endpoint summary

Additional information

A number of bacterial reverse mutation (Ames) assays have been performed on 2 -(2 -methoxyethoxy)ethanol covering the S. typhimurium strains TA97, TA98, TA100, TA1535, TA1537 and the E. coli strain WP2uvrA. All are consistently negative.

There is no in vitro mammalian cell cytogenic or gene mutation data available for this substance. However, an analogue read across justification is attached to this dossier to justify using read across data from similar source substances.

In an in vitro forward gene mutation assay at the HGPRT locus of CHO cells, 2 -(2 -butoxyethoxy)ethanol did not elicit a positive response when tested up to the maximum recommended dose of 5000ul/ml with and without S9 metabolic activation. In an in vitro cytogenicity assay using Chinese Hamster Ovary cells with and without metabolic activation, there was no evidence of cytogenic properties when tested at doses of 2 -(2 -butoxyethoxyethanol) up to those that cause cytotoxicity. In a GLP and guideline (TSCA) CHO / HGPRT gene mutation assay, TEGME tested at concentrations up to 5000 ug/ml did not produce evidence of mutation with or without exogenous metabolic activation by rat liver S-9.

In a GLP and guideline study, EGnPE tested at concentrations up to 1mg/mL in a mammalian cell gene mutation assay using mouse lymphoma L5178Y cells did not produce evidence of a toxicologically significant increases in the mutant frequency at the TK +/- locus with or without exogenous metabolic activation by rat liver S-9.

In an in vitro cytogenicity assay using 2 -(2 -butoxyethoxy)ethanol in Chinese Hamster Ovary cells with and without metabolic activation, there was no evidence of cytogenic properties when tested at doses up to those that cause cytotoxicity. Brake Fluid DOT 4, a mixture primarily of borated and unborated triethylene glycol methyl ether, was tested for potential to cause chromosomal aberrations (CA) in cultured Chinese hamster ovary cells (CHO), at concentrations up to 5000 micrograms/mL, in the presence or absence of S9 mix. No treatment-related increase in incidence of chromosomal aberrations was observed with the test substance. Positive controls benzo(a)pyrene, and methylmethanesulfonate showed significantly increased CA formation. In a guideline mammalian cell chromosome abberation study using human lymphocytes, EGnPE did not induce statistically significant increases in the frequency of cells with chromosome aberrations in either the absence or presence of a liver enzyme metabolizing system in either of two experiments. The test item was considered non-clastogenic to human lymphocytes in vitro. Because of the structural similarity between the source substances and DEGME, particularly with respect to function groups and their surrounding atomic environment, these results can be reliably extrapolated from the former to the latter. A detailed justification for read across and interpolation between these substances is included in an attachment to chapter 13 included with the lead registrants dossier.

Short description of key information:
Tests with registration substance
- Ames: negative (2 studies)
Tests on a surrogate substances:
- Mouse lymphoma test: negative
- Cytogenicity assay (CHO): negative

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

It can be concluded from the data available that mutagenicity and genotoxicity are not likely to be manifest by 2-(2-methoxyethoxy)ethanol and therefore classification for this end point is not warranted.