The glyphosate (aka Roundup) carcinogen controversy isn’t over yet, but the EPA’s stance on direct exposure may affect regulatory and legal outcomes on residual exposure in foods.

According to an August release, the agency is issuing guidance to registrants of glyphosate-based herbicide products to ensure clarity on labeling of the chemical on their products’ packaging. EPA will no longer approve product labels claiming glyphosate is known to create cancer—“a false claim that does not meet the labeling requirements of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA).” 

According to EPA, “The state of California’s much criticized Proposition 65 has led to misleading labeling requirements for products (like glyphosate) because the law misinforms the public about the risks they are facing.” EPA further states: This action will ensure consumers have correct information, and the move is based on EPA’s comprehensive evaluation of glyphosate.  

EPA disagrees with the World Health Organization’s (WHO’s) International Agency for Research on Cancer’s (IARC’s) classification of glyphosate as “probably carcinogenic to humans.” Since the 2015 IARC classification, EPA scientists performed an independent evaluation of available data to reexamine the carcinogenic potential of glyphosate and concluded that glyphosate is “not likely to be carcinogenic to humans.”

According to a glyphosate fact sheet from the National Pesticide Information Center (NPIC) at the Oregon State University, glyphosate is low in toxicity. Animal and human studies were evaluated by regulatory agencies in the U.S., Canada, Japan, Australia and the EU, as well as groups of the U.N. and WHO, which showed that glyphosate is not likely to be carcinogenic to humans.

Additional research published by BMC research journals in August showed that the intake of glyphosate doesn’t substitute for glycine or other proteins of actively dividing human cells, which is good news. The theory, disproven by the research, assumed that glyphosate substitutes for the amino acid glycine in the proteins that make up our body tissues, causing protein misfolding and toxicity. This substitution was thought to lead to health problems such as diabetes and obesity. This research, however, didn’t look at other potential mechanisms of glyphosate’s potential toxicity, including oxidative stress, a process that may cause DNA damage and lead to cancer.

2015 IARC study not accurate?

According to Dr. Kathryn Guyton, IARC scientist and acting head, Monographs Group, IARC evaluated glyphosate based on research up to 2015, and at that time glyphosate was classified in Group II-A, “probably carcinogenic to humans.” 

“Monograph’s evaluation is based on the systematic assembly of all the published, publicly available research relevant to the topic,” says Guyton. “The classification indicates the strength of evidence that a substance may cause cancer. It does not indicate the level of risk from a particular substance.” 

California’s Proposition 65 states that glyphosate is on Prop 65’s toxic chemical list “because it has been identified as a carcinogen.” Prop 65 requires businesses to determine if they must provide a warning on the label about exposures to listed chemicals. Though Prop 65’s glyphosate page suggests that direct exposure to glyphosate can result from skin contact or breathing aerosol droplets in applying glyphosate herbicides, it is unclear about indirect exposure from residuals in foods: “Glyphosate has been detected in a variety of foods, but available information on levels in food is limited. It is unclear if consumption of any specific food would pose a significant cancer risk from glyphosate exposure.” The NPIC basically finds residual levels in food as not being a cancer risk.

The same Prop 65 webpage points to FDA’s Q&A on glyphosate as having established tolerances for glyphosate on a wide range of crops including corn, soybeans, oil seeds, grains, and some fruits and vegetables ranging from 0.1 to 310 ppm (1,000-31,000 ppb). Therefore, if a well-known cereal tests positive for glyphosate at 833 ppb, that is still under the FDA level of 0.1 ppm.

One way to get around the Prop 65 regulations is to prove your product has no glyphosate. Some organic food and beverage producers are on a mission to prove their products are free of glyphosate by undergoing testing with the Detox Project. Joolies, California’s newest organic medjool date company, is the most recent of a select group of 40 brands to receive the Glyphosate Residue Free Certification by the Detox Project, and the first farm to have its harvest certified.

A blog, “How safe are ‘safe’ levels of glyphosate,” on the Detox Project website, however, points to a problem with recent research. Most testing has been short term, feeding rats large doses of glyphosate over a couple of years, but little testing has been done in humans subjected to small doses of glyphosate in their food over extended periods of 10 years or more.