The US Food and Drug Administration (FDA) announced in February that it would, for the first time, begin testing foods such as soyabeans, corn, milk and eggs for residues of the weed killer, glyphosate.

World Health Organization (WHO) cancer experts last year said the chemical was a probable human carcinogen.

Glyphosate is the active ingredient in Roundup, the most widely used herbicide in the world, which is produced by Monsanto. Its use rocked after Monsanto introduced “Roundup Ready’ crops, such as soyabeans and corn, in the mid-1990s. These were genetically engineered to be immune to glyphosate, meaning farmers could spray the pesticide directly over their crops, Civil Eats said. As glyphosate was now off patent, hundreds of herbicide products around the world contain it.

FDA press officer Lauren Sucher told Civil Eats that “the agency is now considering assignments for fiscal year 2016 to measure glyphosate in soyabeans, corn, milk and eggs, among other potential foods.”

Both the FDA and the US Department of Agriculture (USDA) routinely conduct testing of foods for residues of hundreds of pesticides but have not tested for glyphosate.

“Glyphosate levels, if present in genetically engineered corn and soybeans, are likely to be reduced by the processing done to those foods,” FDA press officer Lauren Sucher told Newsweek.

While some European countries like Denmark, Sweden, France and the Netherlands had imposed restrictions to limit humans’ direct contact with Roundup, in 2013 the EPA raised the threshold for which humans could be exposed to glyphosate in some foods, Newsweek said.

Monsanto denies that glyphosate is a carcinogen but faces several lawsuits from farmers who say the exposure to the chemical caused their cancer.

In a statement to Civil Eats, Monsanto said: “Glyphosate’s 40-year history of safe use has been upheld by the US Environmental Protection Agency and and regulators around the world following decades of study and review. Not data have every indicated residue levels of more than a fraction of the EPA’s very conservative Allowable Daily Intake. If the FDA does move forward with additional testing in a scientifically rigorous manner, we are confident it will reaffirm the long-standing safety profile of this vital tool used by farmers, landowners and homeowners around the world.”