Determination of potential dermal exposure during application of crop protection products by boom spraying

The margin of safety is an increasingly important index relating to crop protection products. It relates the available toxicological evidence for the chemical to exposure when the material is used. Determination of potential dermal exposure is an essential element in the calculation of the margin of safety. In the early 1980s a considerable amount of work was done by the British Agrochemicals Association Limited (B.A.A.) on potential dermal exposure. Since that research was undertaken the results obtained have often been used as a model to estimate potential dermal exposure for other crop protection products. This paper presents the findings of a study of potential dermal exposure during boom spraying of an oil-seed rape crop. The conclusions of this study are two-fold. For the application technique studied, the data for mixing and loading generated in the 1980s are inappropriate for prediction of operator exposure and consequent calculation of margin of safety for a product. Also, in future exercises, exposure data should be collected during equipment washing after spraying.