N-phenylmaleimide

Endpoint summary

Additional information

The original sources of test substances in A1) and B1) tests are Nippon Shokubai and the original sources in A2) and B2) tests are other company. So, the result may be affected by the impurities in the test substance. However as this cannot be definitively proved, an appropriate in-vivo somatic cell genotoxicity study is being performed as triggered by REACH Annex VIII Section 8.4 Column 2.

Toxicity test	Result	Remarks	Source of test substance Purity(%)	Test Guideline
A1) bacterial reverse mutation assay (e.g. Ames test)	negative	10 ug/plate: where antibacterial activity were shown	Nippon Shokubai>99.9%	JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals
A2) bacterial reverse mutation assay (e.g. Ames test)	Positive atTA98 and TA1537 with the non-activation method (-S9) .	Confirmation test:6 ug/plate or more are positive reaction	Daihachi Chemical Industry>99.2%	JAPAN: Guidelines for Screening Mutagenicity Testing Of Chemicals
B1) in vitro mammalian chromosome aberration test	negative	test concentration: <= 5 ug/plate	Nippon Shokubai>99.9%	OECD 473
B2) in vitro mammalian chromosome aberration test	Positive at the additional high concentration test without metabolic activation	This positive result is considered as equivocal due to these positive findings generated only at fighly toxic/cytotoxic concentrations. (REACH Guidance R.7a R.7.4.1)	Daihachi Chemical Industry>99.2%	OECD 473
C) in vivo micronucleus study	Negative at toxic doses	-	Nippon Shokubai>99.8%	OECD 474

 

Short description of key information:
Genetic toxicity data (Amest and Chromosome aberration) show negative with the test sample provided by NIPPON SHOKUBAI.
Genetic toxicity data (Amest and Chromosome aberration) show positive with the test sample provided by Daihachi Chemical. The positive result is considered as equivocal due to these positive findings generated only at highly toxic/cytotoxic concentrations. (REACH Guidance R.7a R.7.4.1)

As recommended in the REACH Guidance R.7a Table R.7.7-1, appropriate in vivo mutagenicity studies has been considered in case of another submitter whose purity is different from above 2 samples. The in vivo micronucleus study showed a negative result.

Therefore, PMI is considered as non-mutagenic.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

The substance is not considered as mutagenic, and is therefore not classified in accordance with GHS.