RSS-4, DRY SUBSTANCE

Endpoint summary

Additional information

Ames test:

In a gene mutation test according to OECD 471, Magnesium bis (2-ethylbutanoate) was tested, including an independent repeat. The dose range for the range-finding test was determined in a preliminary toxicity assay and was 50 to 5000 µg/plate. The test material was, therefore, tested up to the maximum recommended dose level of 5000 µg/plate. Reliable negative and positive controls were included. No significant increases in the frequency of revertant colonies were recorded for any of the bacterial strains, with any dose of the test material, either with or without metabolic activation. The test material was considered to be non-mutagenic under the conditions of this test.

Chromosome aberration study:

In a chromosome aberration study, cultured peripheral human lymphocytes were exposed to different concentrations of Magnesium bis (2-ethylbutanoate), in the presence and absence of S9 -mix according to OECD 473 guideline and GLP principles in two experiments.

In the first cytogenetic assay, Magnesium bis (2-ethylbutanoate) was tested up to 2546 μg/mL (= 0.01 M) for a 3 h exposure time with a 24 h fixation time in the absence and presence of 1.8% (v/v) S9-fraction.

In the second cytogenetic assay, Magnesium bis (2-ethylbutanoate) was tested up to 2000 μg/mL for a 24 h and 48 h continuous exposure time with a 24 h and 48 h fixation time in the absence of S9-mix. Appropriate toxicity was reached at this dose level. In the presence of S9-mix Magnesium bis (2-ethylbutanoate) was tested up to 2546 μg/mL for a 3 h exposure time with a 48 h fixation time.

Magnesium bis (2-ethylbutanoate) did not induce a statistically significant or biologically relevant increase in the number of cells with chromosome aberrations in the absence and presence of S9-mix, in either of the two independently repeated experiments.

No effects of Magnesium bis (2-ethylbutanoate) on the number of polyploid cells and cells with endoreduplicated chromosomes were observed both in the absence and presence of S9-mix. Therefore it can be concluded that Magnesium bis (2-ethylbutanoate) does not disturb mitotic processes and cell cycle progression and does not induce numerical chromosome aberrations.

It is concluded that Magnesium bis (2-ethylbutanoate) is not clastogenic in human lymphocytes.

Mouse lymphoma study:

An in vitro mammalian cell gene mutation test with L5178Y mouse lymphoma cells with Magnesium bis (2-ethylbutanoate) was conducted according to OECD 476 guideline and GLP principles.

In the first experiment, Magnesium bis (2-ethylbutanoate) was tested up to concentrations of 2546 μg/ml (~ 0.01 M) in the absence and presence of 8% (v/v) S9-mix. In the second experiment, Magnesium bis (2-ethylbutanoate) was again tested up to concentrations of 2546 μg/ml, but in the absence and presence of 12% (v/v) S9-mix. No toxicity was observed at this dose level in the absence and presence of S9-mix.

In the absence and presence of S9-mix, Magnesium bis (2-ethylbutanoate) did not induce a significant increase in the mutation frequency in both experiments.

In conclusion, Magnesium bis (2-ethylbutanoate) is not mutagenic in the TK mutation test system.

Justification for selection of genetic toxicity endpoint
One Ames test, one chromosome aberration study and one mouse lymphoma study are available.

Short description of key information:
Magnesium bis (2-ethylbutanoate) was evaluated for its mutagenic potential in the Ames test according to OECD Guideline 471 and GLP principles.
A chromosome aberration study with Magnesium bis (2-ethylbutanoate) was performed according to OECD 473 guideline and GLP principles, in cultured peripheral human lymphocytes.
The in vitro mouse lymphoma assay with Magnesium bis (2-ethylbutanoate) was conducted according to OECD 476 guideline and GLP principles.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on the negative results observed in three reliable in vitro genotoxicity tests (an Ames test, a chromosome aberration test and a mouse lymfoma assay), Magnesium bis (2-ethylbutanoate) does not have to be classified and has no obligatory labelling requirement for genetic toxicity in accordance with Regulation EC No. 1272/2008.