Sodium 3-mercaptopropanesulphonate

Endpoint summary

Description of key information

1. Skin irritation (1987), GLP, OECD 404, rabbits, occlusive, 0.5 mL of undiluted test substance, not irritating
2.  Eye irritation (1987), GLP, OECD 405, rabbits, 0.1 g of pure test substance, not irritating
3. Prediction using TOXTREE (v.2.5.0), Chemservice S.A., 2011

Key value for chemical safety assessment

Skin irritation / corrosion

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Additional information

Skin irritation:

The skin irritation potential of the test substance was investigated in rabbits (Dickhaus and Heisler, 1987). 1-Propanesulfonic acid, 3-mercapto-, monosodium salt was applied to the shaved or shaved and abraded skin of rabbits (0.5 mL undiluted substance moistened with water (1:1)) for 24 hours under occlusive conditions. The study was performed according to the OECD Guideline 404 with no deviations and according to the good laboratory practice principles, it is considered to be of high quality (reliability Klimisch 2). The criteria of validity of the test system are fulfilled. After this period the skin was evaluated after 24, 48 and 72 hours and 7 days. After 24 -hours, or at any later time point no changes of the skin of any animal were observed. Because these observations occurred under the existing strict experimental conditions, the product can be regarded as not irritating to the skin. The contact of the product as a powder with the normal human skin can not be considered as dangerous. With an index of zero for primary irritation, the product 1-Propanesulfonic acid, 3-mercapto-, monosodium salt (MPS) is considered to be not irritating to the skin (ETAD SUBCOMMITTEE FOR TOXICOLOGY).

Eye irritation:

1-Propanesulfonic acid, 3-mercapto-, monosodium salt (MPS) was investigated for its potential to cause irritation in the rabbit eye according to OECD TG405 (Dickhaus and Heisler, 1987). The study was performed according to the OECD Guideline 405 without deviations and according to the good laboratory practice principles, it is considered to be of the highest quality (reliability Klimisch 1). The criteria of validity of the test system are fulfilled. 0.1 g of pure substance was instilled into the conjunctival sac, the untreated eye served as control. The reading of eye changes was performed after 1, 2, 4, 8, 24, 48, 72 and 96 hours and after 7 days. Only slight redness of the conjunctiva and slight chemosis occurred, which was all reversible within 4 hours. Therefore the test substance is considered to be not irritating to the eyes. According to classification criteria in EU Directive 67/548/EWG and EG Regulation 1272/2008 the test substance is not irritating to eyes and should be unclassified.

Prediction using Toxtree

For the estimation of eye irritation/corrosion potential of 1-Propanesulfonic acid, 3-mercapto-, monosodium salt was entered into the Toxtree modelling tool. 1-Propanesulfonic acid, 3-mercapto-, monosodium salt is assessed as not eye and skin corrosive.For eye irritation and corrosion “no skin corrosion R34 or R35” is predicted (taking into account the calculated melting point above 200°C). No skin corrosion or irritation potential is identified (taking into account the calculated melting point above 200°C).

Justification for classification or non-classification

Skin irritation:

According to the European regulation (EC) No. 1272/2008 the test material does not meet the criteria for classification and will not require labelling as irritating to the skin.

Eye irritation:

The mean grades of ocular reactions at 24, 48 and 72 h p.a. were lower than the value classified as irritating to the eyes by the European regulation (EC) No. 1272/2008, therefore the substance should not be classified.