The role of formulation co‐ingredients in skin and glove barrier protection against organophosphate insecticides

Abstract

BACKGROUND: Commercially formulated pesticide products are complex mixtures of one or more active ingredients and several co-ingredients. However, the modifying effect of co-ingredients on skin uptake and glove barrier protection has been poorly studied. The aim of this study was to understand the role of formulation co-ingredients in skin and glove barrier protection performance against organophosphate insecticides. RESULTS: We adapted standard in vitro diffusion cell methods to test permeation kinetics of two commonly used organophosphate insecticides: dimethoate and omethoate. For spray dilutions, dimethoate and omethoate did not reach breakthrough glove permeation rate (1 ∼g•cm −2 •min −1 ) and no or little skin permeation was observed for up to 8 h, regardless of formulation. For exposure conditions involving highly concentrated products, significant differences in glove permeation were observed between different formulations of dimethoate (about 1.5-fold, P < 0.05) and of omethoate (184-fold, P < 0.001). In contrast, no difference (P > 0.05) was observed between formulations in terms of skin permeation.CONCLUSION: These results suggest that co-ingredients play a critical role in glove barrier protection against undiluted organophosphate insecticides, whereas their influence on skin uptake was insignificant within the exposure time tested. This implies that dermal exposure risk may vary between handling different formulated products of the same active ingredient hence recommending a common glove material for different formulations of the same chemical without careful consideration of co-ingredients and their permeation properties may not necessarily be appropriate.

Exposure Routes and Health Risks Associated with Pesticide Application

“…People are not only directly exposed to pesticides in occupational, agricultural, and household activities [37][38][39] through different application methods [40], they are also indirectly exposed to pesticides via contaminated environmental media, including air, water, soil, and food [10,11,[41][42][43]. These different types of exposure determine the degree of toxicity of pesticides [6,13,40].…”