Sodium 3-mercaptopropanesulphonate

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Skin sensitisation:

1-Propanesulfonic acid, 3-mercapto-, monosodium salt (MPS) was investigated for its sensitising potential based on the buehler test procedure (deviations: only 15 test animals, open epicutaneous application, 3 times 5 daily applications, same dose in induction and challenge) in guinea pigs (Dickhaus and Heisler, 1987). The test included three phases: induction phase, when test material is applied to hair free skin of test animals openly on the epidermis for a total of fifteen applications; two-week rest period during which an immune response may develop and challenge phase during which the immune system if sensitised reacts hypersensitive (2 applications in a 24 hour rhythm).0.5 g of test material moistened with sterile water was used in the induction phase and in the challenge phase. Treated skin sites were scored according scale as described in the Buehler test method. 24, 48 and 72-hour readings were performed after the challenge applications. No skin reactions were noted at the treated sites of the test or control group animals at the 24 or 48 -hour reading. In conclusion, no skin reactions were observed and therefore the substance is considered to be not sensitising.

The deviations are not considered to bear the potential to miss a inherited potential to act as a sensitiser. Therefore the results of this study are considered to be reliable and valid.

Prediction using TOXTREE

According to the results of TOXTREE modelling tool, 1-Propanesulfonic acid, 3-mercapto-, monosodium salt is estimated to be negative for skin sensitisation potential. The test substance is not electrophile reactive. No structural alerts are identified for the possibility of nucleophilic substitution, Shiff base formation or addition-elimination reactions. There are no functional groups which can act as Michael acceptors.

Migrated from Short description of key information:
1987, in vivo guinea pig, similar to buehler test (OECD 406), not sensitising

Justification for classification or non-classification

Under the conditions of the test, the test material produced a 0% sensitisation rate and was classified as a non-sensitiser to guinea pig skin.

The test material did not meet the criteria for classification as a sensitiser according to EU labelling regulations Commission Directive 93/21 /EEC. No symbol and risk phrase is required.