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An in vivo study determined the effect of inhalation exposure of commercial hexane on rat bone marrow (Daughtrey, 1994; Klimisch score =1). Groups of 5 male and 5 female rats were exposed to 0, 900, 3000, and 9000 ppm of test substance vapor for 6 hrs/day for 5 days. 0.5 mg/kg triethylenemelamine was used as a positive control substance. Animals were sacrificed 3 or 21 hours after exposure, and the bone marrow from their femurs examined for cell aberrations. Because no statistically significant increases in cell aberrations were identified, in any of the test groups, the test substance was classified as not mutagenic.

An in vitro study evaluated the mutagenicity of vapors of commercial hexane. According to the study report (API, 1989; Klimisch score =1) plates ofS. typhimuriumwere exposed for seven to eight hours to test atmospheres of 0, 600, 1000, 3000, 6000, or 9000 ppm of test substance. Commercial hexane did not produce a positive response in any of the test strains.

Two in vitro studiesdetermined the mutagenicity of commercial hexane for Chinese hamster ovary (CHO) cells. In one study CHO cells were exposed to concentrations of 0, 0.132, 0.098, 0.063, 0.0362, or 0.0122 ul/ml both with and without metabolic activation for 5 hours (API, 1990; Klimisch score =1). The cells were then analyzed for mutation frequency. The test substance was found not to be mutagenic both in the presence and absence of metabolic activation. However, the test substance was cytotoxic at concentrations of 0.063 ul/ml or greater.

In the second in vitro study CHO cells were exposed to commercial hexane at concentrations of 0, 0.015, 0.034, 0.074, 0.123, and 0.416 ul/ml without metabolic activation and 0, 0.014, 0.022, 0.056, 0.118, and 0.251 ul/ml with metabolic activation (Daughtrey, 1984; Klimisch score =1). 0.5 ug/ml triethylenemelamine was used a positive control without metabolic activation and 50 ug/ml cyclophosphamide was used as a positive control with metabolic activation. Negative and positive controls were found to be valid and no significant increase in chromosome aberrations were found. The test substance was however found to be cytotoxic at concentrations of 0.074 ul/ml or greater. The test substance is not clastogenic.

All studies were conducted in a manner similar or equivalent to currently established OECD guidelines.


Short description of key information:
There were three in vitro genetic toxicity studies and one in vivo genetic toxicity study identified for hexane solvent containing between 5 and 80% n-hexane.

All genetic toxicity tests, both in vitro and in vivo, were negative

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Hexane solvent containing between 5 and 80% n-hexane is not classified for genetic toxicity.