Registration Dossier

Diss Factsheets

Administrative data

Description of key information

A 28-day oral toxicity study with the methyl-ester of 3-mercaptopropionic acid (MMP) in rats showed only minor effects on organ weights as well as forestomach hyperplasia at the highest dose level (100 mg/kg/day). These effects are not adverse or relevant for human risk assessment. The NOAEL for MMP is equivalent to a NOAEL of 88.3 mg/kg/d for 3-mercaptopropionic acid (MPA).

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
88.3 mg/kg bw/day

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

 


A subchronic toxicity study (OECD TG 408) is required for 3-MPA. However, due to the corrosive properties of 3-MPA, testing on the substance itself is likely to produce prominent local effects to the gastrointestinal tract which may interfere with interpretation of the study. Therefore, based on the low toxicity of the respective alcohols and the hypothesis, that the toxic properties of the category members are based on the MPA moiety with the SH group, data obtained with an structurally similar alternative substance, also containing a MPA moiety, can be used to predict the toxicological properties of 3-MPA. Currently, research is ongoing to find a structurally similar substance without the acidic properties of 3-MPA. If no alternative can be identified, testing will be proposed with neutralized 3-MPA, e.g. sodium mercaptopropionate.

Justification for classification or non-classification

No specific organ toxicity was noted in this study. A STOT or R48 classification is not warranted.