Q. Is paraquat neurotoxic?

A. The neurotoxic potential of paraquat has been extensively studied in laboratory animals. No clinical signs of neurotoxicity or consistent neuropathological changes have been reported following long-term exposures of dietary administration of paraquat to rodents or dogs in regulatory-compliant studies. Paraquat did not result in neurotoxic effects in modern US EPA guideline-compliant oral acute and sub-chronic (90 day) neurotoxicity paraquat studies conducted in 2006. In 2006 US EPA stated “Paraquat does not inhibit cholinesterase activity, produce cholinergic-like toxic signs, or affect morphology of the central or peripheral nervous systems. Furthermore, the molecular structure is not similar to those of compound classes known to have effects on the nervous system. Clinical signs of toxicity did not indicate neurotoxicity. As there is limited concern for neurotoxicity resulting from exposure to paraquat, neurotoxicity studies, including a developmental neurotoxicity study, are not required at this time.” We have extensive data on the safety of our products in use and there is no evidence of neurotoxic effects in humans associated with paraquat.