MSMA: Knowledge Gaps to Aid Appropriate Regulation of an Efficacious Herbicide

Abstract

Monosodium methyl arsenate (MSMA) is an efficacious postemergence herbicide commonly used in cotton ( L.) and turfgrass systems. Concerns have arisen about potential adverse effects of MSMA-derived arsenic on human and environmental health. The USEPA enacted a phase-out of MSMA and other organic arsenical pesticides in 2006, although subsequent agreements allow for its continued use until a review is complete in 2019. Additional research is needed to further characterize MSMA environmental fate and species transformation kinetics in cotton and turfgrass systems of varying edaphic conditions, as there are current knowledge gaps and discrepancies in previous reports. Improved understanding of MSMA environmental fate under real-case conditions will allow regulatory agencies to devise appropriate regulations and management plans to ensure environmental and human health are protected.