Paraquat dichloride, or Paraquat, is a weed-killing product and pesticide widely used in the United States. In recent years, Paraquat has become even more widely used as plants have become more resistant to another pesticide, Roundup, which faces lawsuits. According to the US Geological Survey’s (USGS) National Water-Quality Assessment (NAWQA), more than 10 million pounds of Paraquat were applied to crops in the United States in 2018 alone.

The lawsuits named Syngenta and Chevron Phillips Chemical Co. and Growmark Inc. as defendants. Chevron distributed and sold a Paraquat formulation known as Gramoxone in the United States in an agreement with a Syngenta predecessor called Imperial Chemical Industries. (ICI). ICI introduced Paraquat-based Gramoxone in 1962. Under a license agreement, Chevron had the right to manufacture, use, and sell the Gramoxone formulation in the United States. That formulation was produced by ChemChina’s Syngenta Group and Chevron.

Several studies have linked Paraquat to Parkinson’s disease, a degenerative nervous system disorder leading to mild or severe disability. Europe, China, Brazil, and many other countries have banned the use of Paraquat. The U.S. Environmental Protection Agency, EPA, has approved Paraquat only for licensed commercial use under strict guidelines. The EPA states that Paraquat is highly toxic but finds studies linking Paraquat with Parkinson’s disease inconclusive.

To date, multiple plaintiffs have sued Syngenta Group and Chevron, alleging “that manufacturers and sellers of Paraquat deliberately concealed the dangers of Paraquat for at least four decades, hid evidence of its dangers from government safety agencies, and knowingly unleashed a product they knew caused Parkinson’s Disease on the public.”