Some of the country’s top corn producers are suing Syngenta for allegedly damaging the U.S. corn industry by selling MIR 162 corn seed, also known as Agrisure Viptera, that was not approved for export to China — the world’s third-largest importer of U.S. corn. Corn producers that have not yet taken legal action are being asked to join a mass tort where hundreds of cases have been centralized.

Plaintiffs in the Syngenta corn mass tort include farmers who produced Viptera corn during the 2014-2014 growing season, as well as corn exporters, storage companies, brokers and others in the U.S. corn market. Plaintiffs claim they would not have purchased, planted, harvested or sold the corn if they knew it would be rejected by China.

Up until recently, Chinese officials were turning away millions of tons of U.S. corn shipments for fear that they contained corn from the MIR 162 corn seed, a genetically modified strain that contains the pesticide Viptera. The GMO corn is designed to protect crops against corn pests like black cutworms and corn earworms.

Syngenta began selling Viptera corn seed to American farmers in 2010, and it was approved in Brazil and Argentina in the same year. U.S. farmers claim they were not told that the seed was not approved by China, costing them an estimated $1-$3 billion in losses during the 2013-2014 harvest season. In December, Chinese Vice Premier Wang Yang announced that Viptera corn had finally been approved by China’s Ministry of Agriculture after years of review.

Despite the approval, lawsuits against Syngenta continue over alleged losses already incurred in the U.S. corn market. The lawsuits allege that Syngenta marketed MIR 162 despite knowing that China and many other countries would not purchase it.

Even corn farmers who did not grow the Viptera corn strain were reportedly impacted by China’s rejection of American corn, stating that it created a surplus of crop which reduced corn prices of the crop years 2013-2014 dramatically.

According to many of these GMO corn lawsuits, Syngenta encouraged farmers to plant MIR 162 seeds in parallel planting lines to other corn seeds, despite knowing that these GMO corn seeds could cross-pollinate with other crops. By executing this marketing campaign, Syngenta spread the coverage of MIR 162 seeds, which ultimately affected the entire corn supply of America. This allegedly put corn exports to other countries at risk, because many of them did not approve MIR 162 corn.

Earlier this month, a mass tort was created to centralize hundreds of Syngenta corn lawsuits and class action lawsuits filed across the country.

Legal experts state that the biggest challenge to the Syngenta corn mass tort is to prove causation. The plaintiffs’ attorneys will have to prove their profit loss was a direct result of Syngenta’s fraudulent actions. It is expected that the defense attorneys will try to pitch other explanations for the price decrease in America’s corn market.

Syngenta’s response to the legal action is that farmers are actually the responsible parties, stating that they should take ownership for the risk involved in being a crop producer. Plaintiffs’ lawyers disagree, stating that Syngenta is directly responsible for the economic crisis of the U.S. corn market.