Exposure to pesticide mixer/loaders and applicators in California

Pesticide exposure occurs both when preparing (mixing/loading) the pesticide for application and when actually applying the pesticide. Equipment cleanup and repair may also contribute to exposure. These separate tasks may be done by different people or a single individual may combine them. Different formulations, handling methods, and application methods may affect levels of exposure. Good workplace hygiene dictates that the first priority in workplace safety is to put in place engineering and administrative controls to make the workplace safer rather than rely on the use of PPE to prevent exposure. Providing a physical barrier, such as closed systems for the mixer/loader and an enclosed cab or cockpit for applicators, is associated with reduced exposures of workers. The Worker Health and Safety Branch in the DPR of Cal/EPA has been monitoring various work task exposures. The results of these studies are summarized in Figures 1-4, where exposure is shown based on both time worked and amount of material handled. The studies were done using dosimeters, skin washes/wipes, and air pumps. Water-soluble packets, which are very popular with users, surpassed closed systems in reducing exposure to mixer/loaders in these studies. Hand spraying proved to present the greatest risk of exposure of the methods of application studied. It was found that the dermal route of exposure is most important, comprising 87-95% of a handler's exposure. Although this survey cannot be considered conclusive, since it leaves many formulations, systems, and methods incompletely studied or unstudied, it is clear that exposure is affected by different handling strategies. Manufacturers, regulators and users should work more closely to refine or develop new systems for safely handling pesticides.