2'-methylacetoacetanilide

Endpoint summary

Additional information

Ames test key study:

Number of revertant colonies per plate in all doses with/without S9 mix were equivalent to control. On the other hand, more than two times revertant colonies were observed in all positive controls. Visible precipitation was not observed in any plates.

When tested at dose levels of up to 5000 microg/plate in five strains with or without S9 mix no toxicity was observed. A top dose level of 5000 g/plate was chosen for the subsequent mutation study. The concurrent positive control compounds demonstrated the sensitivity of the assay and the metabolising activity of the liver preparations.

Therefore, Acetoacet-o-toluidide is not mutagenic toSalmonella typhimuriumandEscherichia coli.

Ames supporting study:

The test compound (AAOT Composite sample) and the control compound (ortho—Toluidine) failed to produce a significant response in any of the Salmonella tester strains, either in the presence or absence of the rat liver (S9) activation System. The AAOT composite sample and ortho—Toluidine are therefore judged to be negative in the Salmonella/Microsome Mutagenicity assay as tested.

CA study:

Those more than 5% responses were observed only at concentration levels higher than 10 mM (1,910 ug/mL). Therefore the response was regarded as a biologically irrelevant phenomenon under unphysiological (high osmolality) culture condition.

AAOT induces weak clastogenicity at only concentration levels higher than 10 mM. AAOT dose not induce polyploid. Therefore, AAOT is considered to be not induces Chromosomal aberration.

HGPRT assay:

Acetoacet-o-toluidide was considered negative in the CHO/HGPRT test at dose levels up to 1.5 mg/mL, the limit of solubility. Induced mutation frequencies in the S9 activation portion of the assay were elevated above the concurrent negative control (which was a typically low) but not the historical negative control values. These facts, plus the absence of a dose-response relationship, formed the basis of the decision.

UDS test:

The AAOT Composite sample failed to produce a significant amount of UDS, compared to the negative controls, and therefore does not meet the minimum criteria for a positive test . The combined AAOT sample is therefore judged to be negative in the Unscheduled DNA Synthesis Test.

Short description of key information:
There are two results from bacterial tests and three results from non-bacterial in vitro tests reported on AAOT.
BACTERIAL TEST:
The key study was published in the OECD SIDS dossier in year 2003 conducted and reported according to the OECD Guideline for the testing of chemicals 471 and 472 and principles of GLP in year 1999. The supporting Ames study was performed in year 1985 according to the OECD Guideline for the testing
of chemicals 471 and principles of GLP.
All results were negative in Salmonella typhimurium TA98, TA100, TA1535, TA1537 and Escherichia coli WP2uvrA with and without a metabolic
activation system.
NON-BACTERIAL TEST:
The chromosomal aberration test was performed according to GLP standards and in compliance with OECD Test Guidelines 473.
Some cytotoxicity were observed as well as visible precipitation was shown see thereto table "any other information on results incl. tables".
Therefore, AAOT is considered to be not induces Chromosomal aberration.
The CHO/HGPRT Forward Mutation Assay was performed according to GLP standards and in compliance with OECD Test Guidelines 476.
Acetoacet-o-toluididewas considered negative in the CHO/HGPRT test at dose levels up to 1.5 mg/mL, the limit of solubility.
The Unscheduled DNA Synthesis Test was performed according to GLP standards and in compliance with OECD Test Guidelines 482 in year 1985.
Acetoacet-o-toluidide was considered negative in the UDS test

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

AAOT was not mutagenic in bacteria up to 5,000 ug/plate [OECD TG471, 472]. Although AAOT showed marginal response in induction of chromosomal aberrations in CHL/IU cells at 2.5 or 5.0 mg/mL, the response was observed only at concentration levels higher than 10 mM (1.91 mg/mL) [OECD TG473]. Therefore, the response was regarded as a biologically irrelevant phenomenon under unphysiological (high osmolality) culture condition. Both the unscheduled DNA synthesis test in rat CD-1 cells and HGPRT assay in CHO cells were negative. Considering all of the in vitro studies available, AAOT is not genotoxic and therefore will not be classified.