Contact sensitivity to selected acrylate compounds in B6C3F1 mice: Relative potency, cross reactivity, and comparison of test methods.

Given the increasing prevalence of occupational sensitization to acrylate compounds, n-butyl acrylate (BAC), ethyl acrylate (EAC), and trimethylol propane triacrylate (TMT) were recommended by the National Toxicology Program for hypersensitivity testing in female B6C3F1 mice. The objectives of these studies were to determine the irritating and sensitizing potential of these three compounds using an irritation assay, the murine Local Lymph Node Assay (LLNA), and the Mouse Ear Swelling Test (MEST). The minimal irritating concentration for TMT was determined to be 1.0%, whereas BAC and EAC demonstrated no irritation up to 30%, the highest concentration tested. TMT tested positive in the LLNA at concentrations as low as 0.1% whereas an induction concentration of 0.3% was required to elicit a positive response in the MEST. Furthermore, BAC tested negative in the MEST at induction concentrations as high as 30%, but yielded positive results in the LLNA at concentrations as low as 20%. EAC, at all concentrations tested, was negative in both the MEST and the LLNA. Cross reactivity was only seen when mice were sensitized with TMT and challenged with BAG. In these studies, the LLNA was a more sensitive indicator of the allergic potential of these three acrylates when compared to the MEST.