Ethyl 4-chloroacetoacetate

Endpoint summary

Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

In-vitro gene mutation in bacteria

The test item was examined for mutagenic activity in five histidine-dependent auxotrophs of Salmonella typhimurium, strains TA 98, TA 1538, TA 100, TA 1535 and TA 1537, using pour-plate assays. The procedures used complied with OECD Guideline No. 471. Each test, in each strain, was-conducted on two separate occasions. The studies, which were conducted in the absence and presence of an activating system derived from rat liver (S-9 mix), employed a range of levels from 1 to 100 ug per plate, selected following a preliminary toxicity test in strain TA 98. All tests included solvent (dimethyl sulphoxide) controls with and without S-9 mix. No increases in reversion to prototrophy were obtained with any of the five bacterial strains tested, either in the presence or absence of S-9 mix. Inhibition of growth, observed as slight thinning of the background lawn of non-revertant cells and reduction in revertant colony numbers, occurred in all strains following exposure to test item at 100 ug per plate. For reference, the known mutagens benzo[a]pyrene, 2-nitrofluorene, 2-aminoanthracene, 9-aminoacridine and sodium azide were examined under similar conditions. It was concluded that the test item was devoid of mutagenic activity under the conditions of the test.

In vitro cytogenicity / chromosome aberration study in mammalian cells

The test item was tested for its ability to cause structural chromosomal aberrations in cultured mammalian cells. The study was conducted in accordance with OECD-guideline no. 473. Chinese hamster lung fibroblast (CHL) cells were tested in presence and absence of S9-mix at dose concentrations of 19.5 ug/ml, 4.88 ug/ml and 1.22 ug/ml. The appropriate dose levels were determined in a pretest showing an IC50 of approx..20 ug/ml. Duration of treatment was 24 hours. For reference, the known mutagens Mitomycin C and cyclophosphamide were examined under similar conditions. From the test results, it can be concluded that the test item did not induce chromosomal aberrations and can therefore be regarded as non-clastogenic.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

In-vivo mammalian somatic cell study: cytogenicity / erythrocyte micronucleus

The test item was examined in a bone marrow micronucleus test in mice in accordance with OECD guideline no. 474 (Genetic Toxicology: Micronucleus Test). Test animals (20 males and 20 females) were treated orally with three doses (100, 50 or 25 mg/kg-bw) of the test substance. Mice of the vehicle control group (10 males and 10 females) were treated in a similar way with the vehicle only (saline). A positive control group (5 males and 5 females) was concurrently given a single intraperitoneal dose of the mutagen mitomycin C (0.75 mg/kg/bw). At 24 hours after treatment, 10 vehicle controls (5/sex), 30 test animals (5/sex/dose) and 10 positive controls (5/sex) were sacrificed. At 48 hours after treatment, 10 vehicle controls (5/sex) and 10 test animals (5/sex) of the highest dose (100 mg/kg-bw) were sacrificed. At both sacrifice times and for both sexes, the incidences of micronucleated polychromatic erythrocytes (MPE) per 1000 polychromatic erythrocytes (PE) in mice treated with the test item were not statistically significantly higher than those found in the vehicle controls, indicating that treatment with the test item did not result in genotoxicity to bone marrow cells. It is concluded that the test substance did not produce micronuclei in polychromatic erythrocytes in mice under the conditions used in this study.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (negative)

Justification for classification or non-classification

A classification/labelling of the test item based on genetic toxicity testing is not required.