Ammonium mercaptoacetate

Carcinogenicity

Description of key information

No data is available on the carcinogenic potential of ATG by the oral and inhalation routes.

In a non-standard study by dermal route, sodium mercaptoacetate was administered to mice as 0, 1.0 and 2.0% solutions, until all animals died. Differences in the life span and the incidence of neoplasms between experimental and negative control mice were not statistically significant.

Key value for chemical safety assessment

Carcinogenicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via dermal route

Link to relevant study records

Reference

Endpoint:

carcinogenicity: dermal

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Justification for type of information:

see justification in cross-reference

Reason / purpose for cross-reference:

read-across: supporting information

Key result

Dose descriptor:

NOAEL

Effect level:

1 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Conclusions:

By analogy to NaTG, ATG is considered to be non-carcinogenic via the dermal route.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

13.3 mg/kg bw/day

Study duration:

chronic

Species:

mouse

Justification for classification or non-classification

According to the available carcinogenicity data, no classification is warranted for mercaptoacetic acid and its salts.

Additional information

No carcinogenicity data is available on mercaptoacetic acid and its salts by the inhalation or oral routes. The information on the carcinogenicity potential of mercaptoacetic acid and its salts is limited to a study in mice by chronic cutaneous application of sodium mercaptoacetate.

The carcinogenicity of sodium mercaptoacetate was evaluated using 94 Swiss female mice (7 weeks old) from the Eppley colony. 0.02 ml of a 1.0 and 2.0 % solutions of sodium mercaptoacetate in acetone (equivalent to dose levels of 6.6 and 13.3 mg/kg bw) were applied twice per week to the shaved skin (interscapular region) of each of the 49 or 45 mice, respectively. Ninety-three mice served as negative controls. Positive control groups, 40 mice, were treated with 7,12-dimethylbenz-[a]-anthracene. None of the experimental or control mice survived beyond week 120 of treatment. Infectious diseases, such as pneumonia and hepatitis, occurred in a small number of animals, resulting in an increased number of deaths. Large numbers of neoplasms were observed in treated and negative control mice: lymphomas, pulmonary adenomas, hepatic hemangiomas, ovarian neoplasms, and dermal fibromas. Epidermal neoplasms were not observed. Differences in the incidence of neoplasms between experimental and negative control mice were not statistically significant. No significant decrease in the life span of mice in experimental groups was observed. The authors concluded that sodium mercaptoacetate was not carcinogenic (Stenback et al., 1977).