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Key value for chemical safety assessment

Genetic toxicity in vitro

Description of key information

Results of available in vitro studies:

- AMES test: negative.

- Micronucleus test in human lymphocytes: negative.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (negative)

Genetic toxicity in vivo

Description of key information

No study available.

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

The genetic toxicity of the multi-constituent substance " Reaction mass of dodecane-1-thiol and tridodecyl trithiophosphite" was investigated with different types of in vitro tests:

- AMES test: the test item was examined for the ability to induce gene mutations in tester strains of Salmonella typhimurium and Escherichia coli. The five tester strains TA1535, TA1537, TA98, TA100 and WP2 uvrA were used. Experiments were performed both in the absence and presence of S9 metabolic activation, at the following concentrations: 5.0, 2.50, 1.25, 0.625 and 0.313 µl/plate. No increases in revertant numbers were observed, at any dose level, with any tester strain, in the absence or presence of S9 metabolic activation.

- In Vitro Mammalian Cell Micronucleus according to OECD TG 487: the test item was assayed for the ability to induce micronuclei in human lymphocytes, following in vitro treatment in the presence and absence of S9 metabolic activation. Three treatment series were included in the study. A short term treatment, where the cells were treated for 3 hours, was performed in the absence and presence of S9 metabolism. The harvest time of 32 hours, corresponding to approximately two cell cycle lenghts, was used. A long term (continuous) treatment was also performed only in the absence of S9 metabolism, until harvest at approximately 31 hours.

Dose levels were selected for the scoring of micronuclei on the basis of the cytotoxicity of the test item treatments calculated by the cytokinesis-block proliferation index (CBPI). Dose levels for scoring were selected as follows:

- short-term treatment (with and without S9): 2.00, 1.33 and 0.889 μl/ml

- long-term treatment (without S9): 1.00, 0.667 and 0.444 μl/ml.

Following treatment with the test item, no statistically significant increase in the incidence of micronucleated cells over the control value was observed at any dose level, in any treatment series. It is concluded that the test item does not induce micronuclei in human lymphocytes after in vitro treatment,under the reported experimental conditions.

Justification for classification or non-classification

Reaction mass of dodecane-1-thiol and tridodecyl trithiophosphite is not classified for genetic toxicity according to the CLP Regulation (EC.n.1272/2008). For justification see the results of available studies.

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