2,2'-dithiobisethanol

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Bacterial mutagenicity (Ames test): negative with and without metabolic activation in Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537 and E. coli WP2 uvrA (Charles River, 2017) (OECD 471).

In vitro cytogenicity: negative with and without metabolic activation in Chinese hamster ovary cells (RTC, 2017a) (OECD 473).

Mammalian mutagenicity: negative without metabolic activation and equivocal with metabolic activation in L5178Y mouse lymphoma cells (RTC, 2017b) (OECD TG 490).

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (positive)

Genetic toxicity in vivo

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Di-2-hydroxyethyl disulfide has been tested in a valid bacterial reverse mutation assay, according to the OECD TG 471 (1997), and in compliance with GLP, using Salmonella typhimurium strains TA 98, TA 100, TA 1535, TA 1537 and E. coli WP2 uvrA (Charles River, 2017). No increase in the number of revertants was observed in any test strain, with or without metabolic activation. Appropriate positive, negative and solvent controls were added and gave expected results. It is concluded that the test substance is negative for mutagenicity to bacteria under the conditions of the test.

Di-2-hydroxyethyl disulfide has been tested in an in vitro chromosome aberrations assay in Chinese hamster ovary cells, conducted according to OECD TG 473 and under GLP (RTC, 2017a). No test-substance induced increase in the number of cells with aberrations was observed when treated without metabolic activation. Appropriate positive, negative and solvent controls were added and gave expected results. It is concluded that the test substance is negative for clastogenicity under the conditions of the test.

Di-2-hydroxyethyl disulfide has been tested for mutagenicity in mouse lymphoma L5178Y cells according to OECD TG 490, and under GLP (RTC, 2017b). No test-substance induced increase in the number of mutations was observed when treated without metabolic activation. However, a test substance induced increase in the induced mutant frequency (IMF) relative to the global evaluation frequency (GEF) was observed when treated with metabolic activation. This increase occurred only at the highest dose of 193 μg/mL, at which the RTG = 15%. At the next lower dose, 96.3 μg/mL, RTG value 18%, the IMF was lower than the GEF. Appropriate solvent, negative (treatment medium) and positive controls were included and gave expected results. It is concluded that the test substance does not induce mutation at the TK locus of L5178Y mouse lymphoma cells in the absence of S9 metabolic activation. In the presence of S9 metabolic activation, under the conditions of the study, it is not possible to conclude whether the substance is negative or positive for mutagenicity to mammalian cells.