A mixture of branched and linear C7-C9 alkyl 3-[3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]propionates

Endpoint summary

Additional information

In-vitro:

- Gene mutation in bacteria:

The test article was tested for mutagenic activity in Salmonella typhimurium strains TA 1535, TA 1537, TA 98, TA 100 and Escherichia coli WP2uvrA at concentrations ranging from 312.5 to 5000 µg per plate (OECD 471, CIBA, 904260). The tests were conducted, using the preincubation method, on agar plates in the presence and absence of an Aroclor 1254 induced rat liver preparation and co-factors (S9 mix) required for mixed-function oxidase activity. Positive control compounds demonstrated the sensitivity of the assay and the metabolising, potential of the S9 mix. The test was performed without detection of any toxic and/or mutagenic effects. The values of the negative controls were found to be within the acceptable range and the values of the positive controls met the criteria for a positive response. These results confirm the correct performance of the test.

 

- Chromosome aberration in mammalian cells:

The test substance was tested for clastogenic effects on Chinese hamster ovary cells in vitro (OECD 473, CIBA, 914067). The highest concentration of the test material in the experiments without and with metabolic activation was 200 µg/ml (limit of solubility). The addition of higher concentrations of the test substance (dissolved in dimethylsulfoxide) to the culture medium resulted in strong precipitates. The clastogenic activity was assessed at the following concentrations: Experiments without metabolic activation: - 18 and 42 hours incubation time: 50, 100 and 200 µg/ml. Experiments with metabolic activation: - 3 hours incubation followed by 15 hours recovery period: 50, 100 and 200 µg/ml; - 3 hours incubation followed by 39 hours recovery period: 50, 100 and 200 µg/ml. Aroclor 1254 induced rat liver preparation and co-factors (S9 -mix) were used for experiments with metabolic activation. Two hundred metaphases whenever possible were examined from the vehicle control and from the cultures treated with the various concentrations of test substance. At least fifty metaphases each from the appropriate positive controls (cyclophosphamide: with metabolic activation, mitomycin C: without metabolic activation) were analyzed. In studies performed without metabolic activation using 18 and 42 hours incubation no significant increase in the number of chromosome aberrations were observed. In the experiments performed in the presence of a metabolic activation system (3 hours treatment and 15 respectively 39 hours recovery time), no marked increase in the number of specific chromosome aberrations was observed. The number of chromosome aberrations was within the historical control range at all doses assessed. It is concluded that under the given experimental conditions no evidence of clastogenic effects was obtained in Chinese hamster ovary cells in vitro treated with test material.

- Test for unscheduled DNA-synthesis with EC 400-830-7:

In the unscheduled DNA synthesis test according to OECD guideline 482 (1987) primary rat hepatocytes were exposed to test substance concentrations of 0.8, 4, 20, 100, 200, 400 µg/ml in the original experiment and concentrations of 0.2, 1, 5, 10, 20, 50, 100 and 200 µg/ml in a confirmatory experiment for 16 to 18 h (Ciba-Geigy Ltd no. 874225). 400 µg/ml exerted toxicity and was not examined. The mean gross number of silver grains per nucleus was slightly increased in both experiments. Since the increase was not doubled and no dose-response relationship was seen in both experiments, the test article had no genotoxic properties under the experimental conditions used in this study.

To support use as read-across, a data matrix with relevant physico-chemical properties is provided in the section of repeated-dose toxicity. The structure of the substance is shown in the robust study summary.

In vivo:

The in vivo genotoxic potential of the test substance was evaluated in a micronucleus test in bone marrow erythrocytes of young, male and female mice (Tif: MAGf (SPF)) following an intraperitoneal (i.p.) dosing and 16, 24 and 48 h sampling regimen (OECD 474, CIBA, 904259). A toxicity study was undertaken to establish a suitable dose range for the micronucleus experiment. Based on the findings of the toxicity study, the maximum tolerated i.p. dose of the test substance was determined to be 5000 mg/kg bw. In the micronucleus test, the mice were therefore dosed via the i.p. route with the test substance at concentration 5000 mg/kg bw. Bone marrow samples were taken 16, 24 and 48 h after the initial dose. Two control groups of male and female mice were dosed with either the vehicle, 10 ml arachis oil/kg bw (i.p.), or the positive control agent, 64 mg cyclophosphamide/kg bw (oral: gavage). The experimental schedule for the control groups followed that of the test material treated mice. The evaluation of the bone marrow smears showed no statistically significant increase in the number of micronucleated polychromatic erythrocytes in comparison with the negative control animals at the respective sampling times. Animals dosed with cyclophosphamide responded with substantial increases in the numbers of bone marrow micronuclei. It is concluded that under the given experimental conditions no evidence for clastogenic or aneugenic effects was obtained in mice treated with the test item.

Short description of key information:
Genetic toxicity in vitro: Ames test: negative: OECD 471, GLP, CIBA, 1991
Chromosome aberration: negative: OECD 473, GLP, CIBA, 1991
Test for unscheduled DNA-synthesis with related ester: negative: OECD 482, GLP
Genetic toxicity in vivo: MNT: negative: OECD Guideline Study, CIBA, 1991

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Dangerous Substance Directive (67/548/EEC): The available studies are considered reliable and suitable for classification purposes under 67/548/EEC. As a result the substance is not considered to be classified for genetic toxicity under Directive 67/548/EEC, as amended for the 28th time in Directive 2001/59/EC.

Classification, Labelling, and Packaging Regulation (EC) No. 1272/2008: The available experimental test data are reliable and suitable for classification purposes under Regulation 1272/2008. As a result the substance is not considered to be classified for genetic toxicity under Regulation (EC) No. 1272/2008.