EPA has assessed the risks associated with the organophosphate (OP) pesticide ethion, and identified risk mitigation measures and data needed to reduce and better characterize those risks. As reflected in the Agency's reregistration Eligibility Decision (RED) document, the registrants of ethion have requested voluntary cancellation of their products rather than committing to develop the additional data. These data include developmental neurotoxicity studies, and data on the effects of water treatment on ethion in drinking water. The voluntary cancellations will be 'phased-in' to facilitate the users' transition to other products. In the interim before sale, distribution, and use of ethion cease, the registrants have agreed to measures which mitigate the worker and ecological risks associated with ethion.