Registration Dossier

Administrative data

Key value for chemical safety assessment

Additional information

2-isobutyl-2-methyl-1,3-dioxolane-4-methanol has been evaluated in a bacterial mutagenicity assay in vitro (OECD 471) using five strains of Salmonella typhimurium (TA1535, TA1537, TA98, TA100, T102). The test substance did not induce any significant, reproducible increases in the observed numbers of revertant colonies in any strain with or without an auxiliary metabolising system (S9). Under the conditions of this assay, the test substance was considered non-mutagenic.

2-isobutyl-2-methyl-1,3-dioxolane-4-methanol has been evaluated in a chromosome aberration test in vitro (OECD 473) using Chinese Hamster Ovary cells. Under the conditions of the test, the registered substance did not induce structural aberrations in the presence or in the absence of a metabolic activation system.

The analogue substance 2,2-Dimethyl-1,3-dioxolane-4-methanol was evaluated in an in vivo micronucleus test (OECD 474). In this study, the analogue substance did not induce any increase in the number of micronucleated polychromatic erythrocytes in the bone marrow of mice dosed up to 2000 mg/kw bw and is therefore considered not clastogenic and not aneugenic.


Justification for selection of genetic toxicity endpoint
No specific study selected as three genotoxicity studies have been performed.

Short description of key information:
The name of the tested substance for the Ames test was PEX-2, the previous public name of 2-isobutyl-2-methyl-1,3-dioxolane-4-methanol. The specifications of PEX-2 are in line with the dossier and representative of the industrial product.
One Ames test (Viana Silvino, 2011; OECD 471, Rel. 1) is available and gave negative results in the presence or in the absence of metabolic activation.

One in vitro chromosome aberration test (R. Cardoso, 2015; OECD 473, Rel. 1) is available and gave negative results in the presence or in the absence of metabolic activation.

One in vivo micronucleus test is available on the analogue substance 2,2-Dimethyl-1,3-dioxolane-4-methanol (L.F Negro Silva, 2009; OECD 474, Rel. 2). In this study, the analogue substance did not induce any increase in the number of micronucleated polychromatic erythrocytes in the bone marrow of mice dosed up to 2000 mg/kw bw.

Endpoint Conclusion: No adverse effect observed (negative)

Justification for classification or non-classification

Based on absence of mutagenicity in an Ames test, structural aberrations in a in vitro chromosome aberration test, together with negative results in a in vivo micronucleus test performed on the analogue substance 2,2-Dimethyl-1,3-dioxolane-4-methanol, it is concluded that 2-isobutyl-2-methyl-1,3-dioxolane-4-methanol does not have genotoxic potential. Therefore no classification is warranted according to the criteria of Annex VI Directive 67/548/EEC or EU Regulation 1272/2008 (CLP).