The U.S. EPA said on April 30 that glyphosate, a chemical in many popular weed killers, is not a carcinogen, contradicting decisions by U.S. juries that found it caused cancer in people.
The EPA’s announcement reaffirms its earlier findings about the safety of glyphosate, the key ingredient in Bayer’s Roundup. The company faces thousands of lawsuits from Roundup users who allege it caused their cancer.
“EPA continues to find that there are no risks to public health when glyphosate is used in accordance with its current label and that glyphosate is not a carcinogen,” the agency said in a statement.
Farmers spray glyphosate, the most widely used herbicide in U.S. agriculture, on fields of soybeans and other crops. Roundup is also used on lawns, golf courses, and elsewhere.
The EPA did previously find ecological risks from the chemical and has proposed new measures to protect the environment from glyphosate use by farmers and to reduce the problem of weeds becoming resistant to it.
Bayer said it was pleased the EPA and other regulators who have assessed the science on glyphosate for more than 40 years continue to conclude it is not carcinogenic. “Bayer firmly believes that the science supports the safety of glyphosate-based herbicides,” it said in a statement. The company has repeatedly denied allegations that glyphosate and Roundup cause cancer.
But critics of the chemical disputed the EPA’s assurances.
“Unfortunately, American consumers cannot trust the EPA assessment of glyphosate’s safety,” said Nathan Donley, a senior scientist at the environmental group Center for Biological Diversity.
Monsanto developed Roundup as the first glyphosate-based weed killer, but it is no longer patent-protected and many other versions are available. Bayer bought Monsanto last year for $63 billion.
The debate over glyphosate’s safety has put a spotlight on regulatory agencies around the world in recent years and, more recently, on U.S. courtrooms.
In 2015, the World Health Organization’s cancer arm classified glyphosate as “probably carcinogenic to humans.” But the EPA in 2017 said a decades-long assessment of glyphosate risks found the chemical was not likely carcinogenic to humans.
In February, analysts at Brazilian health agency Anvisa also determined the weed killer does not cause cancer while recommending limits on exposure.
In the first U.S. Roundup trial, a California man was awarded $289 million in August 2018 after a state court jury found the weed killer caused his cancer. That award was later reduced to $78 million and is being appealed by Bayer.
A U.S. jury in March awarded $80 million to another California man who claimed his use of Roundup caused his cancer.
What EPA actually determined, including during the Obama administration, was that glyphosate is “not likely to be carcinogenic at doses relevant to human health risk assessment.” This is a risk assessment, asking “What is the likelihood glyphosate will cause cancer at expected levels of exposure?” IARC, on the other hand, did a hazard assessment, asking “Could glyphosate cause cancer under some circumstances?” IARC even stated in its monograph that it does not assess carcinogenic risk. So the agencies are not really in dispute; they just asked and answered different questions, both of which are important.