WASHINGTON, Nov. 12, 2015 - European Union regulators have concluded that the widely used herbicide glyphosate is unlikely to cause cancer, a ruling that runs counter to a controversial assessment issued recently by an arm of the World Health Organization. 

The European Food Safety Authority and the EU member countries announced Thursday that they had finished a re-assessment of glyphosate, best known as Roundup. In addition to deciding that the chemical was unlikely to be carcinogenic the agency also proposed a new safety limit for glyphosate residues in food. 

“This has been an exhaustive process – a full assessment that has taken into account a wealth of new studies and data. By introducing an acute reference dose we are further tightening the way potential risks from glyphosate will be assessed in the future,” said Jose Tarazona, head of EFSA’s Pesticides Unit.

The European Commission will use the finding in deciding whether to keep glyphosate on the EU’s list of approved active substances. EU member governments also will use the decision in re-assessing the safety of herbicides used in their countries. 

A peer review expert group made up of EFSA scientists and representatives from the risk-assessment groups in the EU member countries set a new limit, or “acute reference dose,” for glyphosate of 0.5 milligrams per kilogram of body weight. An acute reference dose is the estimated amount of a chemical substance in food that can be ingested during one meal or one day without posing a health risk.

Charla Marie Lord, a spokeswoman for Monsanto Co., which developed the herbicide, said the new limit is in line with a new, higher limit for life-time dietary exposure. A person would have to eat 880 bounds of fruits or vegetables or 40 bowls of porridge a day to reach the limits, she said. 

The WHO’s International Agency for Research on Cancer's (IARC) earlier this year classified glyphosate as “probably carcinogenic” to humans, a decision that has been widely used by opponents of agricultural biotechnology to attack the use of glyphosate-tolerant crops.

Under the IARC classification of substances, glyphosate is in Group 2A, which suggests there is “limited evidence” of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental animals. Group 2B, “possibly carcinogenic to humans,” includes cell phones and coffee. Group 1 substances are considered “carcinogenic to humans.”

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The EFSA said its analysis covered a “large body of evidence” that included some studies the IARC did not consider, which is one of the reasons the agencies reached different conclusions, the EFSA said. 

All but one of the member country experts in the EU review agreed that neither human nor animal studies showed that glyphosate would cause cancer in people, the EFSA said. 

The Center for Food Safety, an advocacy group critical of biotechnology, believes that the EFSA review was less rigorous than the IARC.

“The cancer experts at the World Health Organization got it right, glyphosate is probably carcinogenic, because they took an unbiased look at the science.  EFSA got it wrong because they bent the rules for assessing studies and rejected valid studies from consideration,” said Bill Freese, science policy analyst for the group.

EFSA will use the new limits in the agency’s planned review next year of the maximum residue levels for glyphosate in food.

The U.S. Environmental Protection Agency, which is undertaking a comprehensive review of glyphosate, said Thursday that it will publish in the next several months the agency’s draft human health and ecological risk assessments. The agency plans to take comment on the review for 60 days. 

EPA plans to issue a proposed interim decision for glyphosate in 2016 and an interim final decision in 2017. The final decision will not be made until after the Fish and Wildlife Service and National Marine Fisheries Service finish a consultation on the impact of glyphosate on endangered species, EPA said in a statement to Agri-Pulse.