Isobutyl acrylate

Endpoint summary

Additional information

In-vitro studies: Bacterial systems

 

Isobutyl acrylate was tested in theassay with Salmonella typhimurium TA98, TA100, TA1535, and TA1537 in concentrations from 100 up to 10000 µg/plate with and without metabolic activation. No mutagenic effects were observed. At 3333 and 10000 µg/plate slight cytotoxicity was observed (NTP 1982, Zeiger 1987).

 

 

In-vitro studies: Mammalian cell gene mutation test

 

There are no mammalian cell gene mutation assays available for isobutyl acrylate. But the structurally-related acrylate esters ethyl acrylate and methyl acrylate were sufficiently tested in both the HGPRT assay and the Mouse Lymphoma TK assay.

The HGPRT assays were all negative without metabolic activation (Moore et al. 1989, 1991). In contrast, both acrylate esters were positive in the Mouse Lymphoma TK+/- mutation assay using L5178Y cells with and without metabolic activation at clearly cytotoxic concentrations (Rohm & Haas 1980, Moore 1988, 1989). The majority of the mutant colonies were small colonies, suggesting that ethyl and methyl acrylate did act via a clastogenic mechanism (Moore 1988, 1989, Amtower 1986).

More recent studies have indicated that there is an association between chromosomal aberrations and cytotoxicity at exposure concentrations which reduce cell growth to less than 50% of the control value (Galloway, 2000 and references cited therein). These data suggest that the increase in mutagenicity reported in the TK assays with ethyl and methyl acrylate may be an artifact of the experimental method.

 

 

In-vitro studies: Genotoxicity tests

 

There are no in vitro micronucleus assays or chromosome aberration tests available for isobutyl acrylate. In accordance with column 2 of REACH Annex VIII, no study has to be conducted since adequate data from an in vivo cytogenicity test are available.

 

 

In vivo studies

 

In a micronucleus test performed with isobutyl acrylate in accordance with OECD guideline 474 under GLP conditions, mice were dosed intraperitoneally with up to 1000 mg/kg bw (males) and 1250 mg/kg bw (females), isobutyl acrylate did not induce micronuclei in bone marrow at any dose level or any harvesting time used in this study (24 and 48 hours after the end of exposure). Isobutyl acrylate was considered non-clastogenic and non-aneugenic in this assay. The mean number of normochromatic erythrocytes was not increased after treatment with the test substance as compared to the controls, indicating that isobutyl acrylate had no cytotoxic effect on the bone marrow, but there were clear clinical signs of toxicity at the highest dose-levels tested (reduced activity, eyelid closure, apathy, prostrate position). The positive control substance, cyclophosphamide, induced a distinct increase of micronuclei (BASF AG 2001).

 

 

 

Conclusion

 

Isobutyl acrylate was not mutagenic in the Ames test and not clastogenic in vivo in the mouse micronucleus test.

Galloway SM (2000). Environmental and Molecular Mutagenesis 35:191-201

Short description of key information:
Isobutyl acrylate was not mutagenic in the Ames test and not clastogenic in vivo in the mouse micronucleus test.

Endpoint Conclusion:

Justification for classification or non-classification

EU classification according to Annex VI of Directive 67/548/EEC: no classification required

GHS classification (GHS UN rev.3, 2009): no classification required