Syngenta is being sued by California resident Apostolos Panayiotou (represented by Wisner Baum LLP), who is alleging that he developed non-Hodgkin lymphoma after routine use of the company’s atrazine-based herbicides.
The lawsuit alleges that Panayiotou developed cancer after routinely mixing, loading, and spraying atrazine products over three decades in Los Angeles County. Also, the suit alleged that Syngenta failed to properly warn consumers and provide training and communications beyond federally approved pesticide labels.
The lawsuit distinguishes between the chemical itself and formulated products, with the lawsuit focusing on finished products that can enter a person’s body through skin contact, inhalation, and ingestion while handling the chemical.
“Mr. Panayiotou handled these products year after year, exactly as they were intended to be used, and he developed cancer. Syngenta knew or should have known about the risks applicators faced, and it failed to warn them,” said Pedram Esfandiary, a partner at Wisner Baum and one of the attorneys representing Panayiotou, in the news release.
Syngenta responds to lawsuit
Syngenta denied the claims and stood by the safety of its atrazine herbicides under registered label instructions, a company representative told AgNavigator.
Leading regulatory bodies and researchers “have concluded that science does not support a causal connection between atrazine and cancer,” the representative noted. This includes the US Environmental Protection Agency (EPA) in 2018 and Canada Pest Management Regulatory Agency in 2023, which both could not determine a link between atrazine use and adverse health outcomes based on current evidence, they added.
“At Syngenta, the health and well-being of people always come first. We stand firmly behind the safety of our atrazine products and the science that supports them. Atrazine is one of the most extensively studied crop protection products in the world, with more than 7,000 studies conducted over six decades. The weight of scientific evidence shows atrazine is safe when used according to registered label instructions, consistent with the conclusions of leading regulatory authorities and scientific expert bodies that have extensively assessed atrazine. As such, Syngenta disagrees with the allegations made in the lawsuit,” said the Syngenta spokesperson.
Atrazine faces scrutiny
Atrazine is a chlorinated triazine systemic herbicide approved by the EPA to control annual grasses and broadleaf weeds in field corn, sweet corn, sorghum, sugarcane, wheat, macadamia nuts, guava, and certain non-agricultural uses.
Syngenta offers liquid and dry granular versions of atrazine with AAtrex 4L and AAtrex Nine-O, respectively, and premixes, including Acuron, Lexar EZ, Lumax, Bicep II Magnum, and others.
The safety of atrazine has faced scrutiny, including by the International Agency for Research on Cancer (IARC), which is referenced in the lawsuit.
IARC evaluated the carcinogenicity of atrazine, alachlor, and vinclozolin and published the results in the January 2026 edition of The Lancet, with researchers determining that atrazine and the herbicide alachlor were probably carcinogenic to humans (Group 2A), based on sufficient evidence in experimental animals and a positive association for non-Hodgkin lymphoma in limited human evidence, according to the agency.
The 2A ranking is the second highest IARC rating, behind the carcinogenic to humans rating, (i.e., Group 1).
The lawsuit alleged that Syngenta knew of this research related to non-Hodgkin lymphoma and immune system suppression and continued to market products without disclosing the risk, the law office stated.
While IARC determines if a substance can cause cancer under some circumstances, agencies like the EPA are responsible for determining the risk of products and approved uses.
As part of its review process, the EPA reviews registered pesticides and herbicides at least every 15 years to ensure that they are being used for their intended purpose and do not create adverse impacts to human health and the environment as required by the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA).
Since its interim registration review decision for atrazine in 2020, the EPA has made a number of changes to the use of the chemical to decrease runoff from fields and protecting life. These efforts include prohibiting aerial applications and applications when soil is saturated or doing rain or storms. Additionally, in July 2024, the EPA updated atrazine concentration to 9.7 micrograms per liter for aquatic plants.
