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Administrative data

Key value for chemical safety assessment

Additional information

Endpoint Conclusion:

Justification for classification or non-classification

In vitro: In a study conducted according to the OECD TG 471 guidelines (SNEA, 1993) 2-mercaptoethanol did not induce reverse gene mutations in Salmonella typhimurium strains in the presence or absence of metabolic activation when tested up to cytotoxic concentrations (concentrations 125, 250, 1000, 2000 µg/plate).

Negative results with and without metabolic activation in Salmonella typhimurium were also reported in a similar study (Phillips Petroleum Company, 1982). In this test, concentrations used were 80, 120, 170, 240, 340, 500, 700 and 1000 µg/ml.

In an in vitro chromosomal aberration test conducted according to the OECD TG 473 guidelines, 2-mercaptoethanol at concentrations up to 5000μg/ml was negative with and without metabolic activation (CIT, 1996).

A positive result without metabolic activation was found in an in vitro mammalian chromosome aberration test using human lymphocytes (Speit et al., 1980). 2-Mercaptoethanol was tested in concentrations up to 780 µg/ml.

Brogger (1975) reported a negative result without metabolic activation in a chromosome aberration test using human lymphocytes. Concentrations tested were 7.8, 39, 78 and 780 µg/ml.

In vivo: In a micronucleus assay according to the OECD TG 474 male and female mice were treated intraperitoneally with 50, 100, or 200 mg/kg bw 2-mercaptoethanol. Males of the high dose group showed a slight but statistically significant increase in the frequency of MPE; but data generated in the additional analysis (further 2000 polychromatic erythrocytes per animal evaluated) showed that there was no significant difference between males of the high dose group and the corresponding control. In none of the other treatment groups the number of micronucleated cells was significantly elevated. The high dose resulted in clinical signs of toxicity. In male mice of the mid and high dose group the ratio of polychromatic erythrocytes to normochromatic erythrocytes was significantly decreased indicating toxic effects in the bone marrow. Under the condition of this study the test substance did not induce damage to the chromosomes or the mitotic apparatus of mouse bone marrow cells (BASF, 2002).

Classification concerning genetic toxicity is not warranted.