The U.S. Food and Drug Administration (FDA) announced on Thursday that it would start testing food products sold in the United States for residues of glyphosate.
Monsanto developed the herbicide glyphosate for U.S. crops and marketed it as Roundup in 1974. The chemical soon dominated the pesticide market, eventually becoming the most-used agricultural chemical worldwide.
How much of the pesticide gets into the food supply, however, has been difficult to determine largely because the regulatory community in the United States said this would be a waste of time and money given that the agrichemical industry already claimed to have proven the chemical as safe.
Monsanto said that trace amounts of the chemical in foods are not harmful and that glyphosate does not pose unreasonable risk to humans and the environment.
The World Health Organization (WHO), however, which conducted a review of more than 400 studies in 2015, rated glyphosate, along with malathion and diazinon, as "probably carcinogenic to humans" in March 2015.
The WHO based its classification on studies in Sweden, Canada and the United States showing that those who work with glyphosate-based herbicides have elevated risks for non-Hodgkin lymphoma, albeit another large U.S. study did not find such link.
With the prevalent use of the chemical and suspected problems linked to use of the weed killer, experts have called for regulators to reassess the chemical's toxicity and to make take the necessary steps to protect people from exposure to the chemical.
"Animal and epidemiology studies published in the last decade, however, point to the need for a fresh look at glyphosate toxicity," says a group of researchers led by John Peterson Myers from Carnegie Mellon University. "Regulatory estimates of tolerable daily intakes for glyphosate in the United States and European Union are based on outdated science."
Myers and colleagues' statement of concern over the use of glyphosate-based herbicides and the risks linked to exposure is published in the journal Environmental Health.
With FDA having developed streamlined methods to test the presence of the chemical in food, the agency is now preparing to measure glyphosate in corn, milk, eggs and soybeans, among other food products.
As for Monsanto, the company said that it is confident that its herbicide is safe.
"If FDA does move forward with residue testing in a scientifically rigorous manner, we are confident it will reaffirm the safe use of this vital tool used safely and effectively by farmers, landowners and homeowners around the world," says Monsanto spokeswoman Charla Lord.