PORTLAND, ORE. - In a sharp rebuke, a new report by a key scientific advisory panel concluded that the pesticides office at the Environmental Protection Agency failed to follow its own guidelines when it found last year that glyphosate — the active ingredient in Monsanto’s flagship pesticide Roundup — is not likely to be carcinogenic to humans.

The panel — an independent group of scientists commissioned by the EPA to review the agency’s work — remained split on whether the pesticide program’s non-carcinogenic conclusion was justified, with some panel members believing there was “suggestive evidence of carcinogenic potential.” Glyphosate is the most heavily used herbicide in the United States, with about 220 million pounds used in 2015 alone.

Last year, in a widely criticized move, the pesticides program at the EPA postponed the advisory panel meeting because CropLife America — an industry trade group representing Monsanto and other pesticide companies — objected to one of the members on the panel. Dr. Peter Infante, a respected researcher with the National Institute for Occupational Safety and Health, was subsequently removed from the panel after CropLife accused the highly credentialed scientist of bias.

“Even with Monsanto’s undue influence on the makeup of this panel, there was still considerable concern about the safety of this pesticide,” said Nathan Donley, a senior scientist at the Center for Biological Diversity. “When the pesticide office doesn’t even follow its own guidelines in determining the safety of glyphosate, how can we trust its conclusions?”

Documents released by court order earlier this week revealed that:

• The chair of the EPA’s Cancer Assessment Review Committee on glyphosate was in regular contact with Monsanto, providing insider information that guided Monsanto’s messaging;

• The chair warned Monsanto that the World Health Organization’s cancer research arm had found glyphosate to be a probable carcinogen months before the 2015 determination became public, allowing the pesticide-maker to mount a public relations attack on the finding;

• The chair promised to thwart the Department of Health and Human Services’ review of glyphosate’s safety, saying that if he was successful he deserved a medal. The Department never did review glyphosate’s safety;

• A Monsanto executive emailed other company officials that they could hire academics to put their names on glyphosate research papers written by Monsanto, citing a previous instance where this was actually done. The referenced paper was in fact used in the pesticide program’s own cancer analysis.

The Center’s scientists and attorneys are closely reviewing the new documents as they are released.

“Monsanto’s troubling influence and coordination with the pesticide office, combined with its utter disregard for established guidelines, completely discredits the pesticide office’s conclusion that glyphosate does not cause cancer,” said Donley. “The 2015 finding of the World Health Organization’s cancer arm that glyphosate is a probable carcinogen remains the most credible and scientifically supported finding on the carcinogenicity of glyphosate. This latest science panel report really just confirms that the pesticide approval process in this country needs to be fundamentally changed to protect public health.”