Download PDF
November 18, 2019

EPA Releases Draft Risk Assessments for Paraquat Dichloride

Bergeson & Campbell, P.C.

On October 15, 2019, EPA posted a total of 11 documents to the registration review docket for paraquat dichloride (EPA-HQ-OPP-2011-0855).  Of primary interest in the registration review process under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) are the draft human health and ecological risk assessments.  Additional supporting documents posted to the docket include dietary, residential, and occupational exposure assessments; a review of analytical chemistry and residue data; a label use summary; a screening level usage analysis, results of a drinking water jar test; open literature and epidemiology literature reviews; and an incident report summary.

Paraquat is currently registered in the United States for use as an herbicide on over 100 crops in agricultural and commercial settings.  All paraquat products are restricted use products and may be applied only by certified pesticide applicators.  EPA has previously imposed additional restrictions and conditions to ensure the safe use of paraquat consistent with label directions.  These actions include a safety awareness campaign, changes to labels and product packaging, and specialized training for certified applicators using paraquat.  Evaluation of the effectiveness of these steps will be conducted in the registration review process.

Potential risks of concern to workers applying paraquat or entering treated fields are identified in the draft human health risk assessment, as are potential risks to bystanders from spray drift.  Prior submissions to EPA suggest a link between proper use of paraquat and Parkinson’s Disease, but EPA’s review of relevant data does not support a causal relationship.  This conclusion is not without controversy, as evidenced by an October 15, 2019, press release from the Center for Biological Diversity that calls out EPA’s failure to recognize a link between paraquat exposures and Parkinson’s Disease.  The ecological risk assessment identifies potential risks to mammals, birds, adult honey bees, terrestrial plants, and algae.  EPA is seeking comments on these and other issues raised in the draft risk assessments for paraquat.  Comments will be accepted on these documents until December 16, 2019.