Effect of laundering on ability of glove fabrics to decrease the penetration of organophosphate insecticides through in vitro epidermal systems.

Two knit glove fabrics, one of 100% cotton and one of 100% polypropylene, were examined for their capability to decrease the penetration of the organophosphate insecticides (OPs), azinphos-methyl and paraoxon after 4 h at field concentrations (3000 and 15 ppm, respectively) through an in vitro epidermal system (Skin2, Advanced Tissue Systems, LaJolla, CA). The glove fabrics were examined under three different conditions of use: new, after they had been abraded and after they had been abraded and then laundered. New and laundered cotton fabric was also examined for its capability to decrease the penetration of azinphos-methyl through another in vitro epidermal system (Epiderm, MatTek Corp., Ashland, MA), after 4 and 24 h of exposure. Capability of the media under the in vitro epidermal systems to inhibit brain acetylcholinesterase (AChE) was used as the indicator of penetration. Results were compared to OP-caused inhibitions seen in media under the fabric alone and in media under the in vitro epidermal systems alone. Incubations of azinphos-methyl suspensions and the in vitro epidermal systems covered with fabric indicated that both the epidermal cells and fabric provided protection against AChE inhibition caused by this OP and that the protective effects were additive, whether measured after 4 or 24 h of exposure. Therefore, neither laundering nor abrasion followed by laundering altered the capability of the in vitro epidermal systems to absorb azinphos-methyl suspension. For paraoxon solution, however, new cotton glove fabric prevented absorption, and this protective effect, noted after 4 h of exposure, was lost when the fabric was laundered. Abrading the fabric did not cause a greater effect than laundering alone. These results suggest that the pesticide as well as its formulation may be factors of consideration when protective fabrics are chosen, and that, for cotton glove fabric, the protection against some OPs may best be provided before the fabric is laundered.