EPA Panel Finds Glyphosate Not Likely to Cause Cancer

By David Schultz

May 2 — Glyphosate, a weed killer developed by Monsanto that is now the most widely used pesticide in the U.S., likely does not cause cancer, according to an Environmental Protection Agency review panel.

The EPA's Cancer Assessment Review Committee made the determination after analyzing several dozen published and unpublished scientific studies of the chemical. The committee finalized its report on Oct. 1, 2015, but did not release it to the public until late April, when the agency inadvertently posted the report online.

The report's findings disagree with a 2015 review of glyphosate by the World Health Organization's International Agency for Research on Cancer (IARC), which found that the pesticide is a “probable carcinogen” (59 DEN A-10, 3/27/15).

WHO's Findings Disputed

The EPA cancer review committee, led by staffers from the Health Effects Division of the agency's Office of Pesticide Programs, poked a number of holes in the methodology used by IARC for its review of glyphosate, which is the active ingredient in Monsanto's Roundup herbicide as well as hundreds of other products made by dozens of other companies.

For example, the EPA report noted that the IARC scientists disregarded several studies on the effects of exposure to glyphosate because these studies showed no positive results. The EPA report also said the studies IARC chose to include in its review had significant limitations.

Release of the IARC finding on glyphosate had serious negative consequences for the agricultural chemical industry.

It was the basis for a decision by California to require all products containing glyphosate to be listed as carcinogenic, a decision that Monsanto is challenging in court (173 DEN A-6, 9/8/15).

The IARC finding also led to numerous product liability lawsuits against Monsanto from people arguing that exposure to the company's pesticide was the cause of their illnesses (230 DEN A-9, 12/1/15).

Monsanto Statement

“No pesticide regulator in the world considers glyphosate to be a carcinogen, and this conclusion by the U.S. EPA once again reinforces this important fact,” Monsanto CEO Hugh Grant said in a statement. “Unfortunately, last year’s inconsistent classification by IARC generated unwarranted concern and confusion about this important agricultural tool.”

The IARC did not immediately respond to requests from Bloomberg BNA for comment.

The EPA review committee's findings are part of a broader look by the agency at the overall health and environmental effects of glyphosate as a part of its registration review program, which conducts risk reviews of every pesticide chemical once every 15 years.

If the EPA determines that the science shows that the way glyphosate is being used now exceeds acceptable risks, it can enact use restrictions on the chemical or take it off the market altogether.

Report Posted April 29

The EPA posted the cancer review committee's report April 29, along with more than a dozen other glyphosate-related documents, to Regulations.gov, an online document repository for federal agencies.

Then, after the report had been widely spread on social media, the cancer review committee's report and the other documents were removed from the EPA website on the afternoon of May 2.

“Preliminary glyphosate documents were inadvertently posted to the Agency’s docket,” EPA spokeswoman Melissa Harrison told Bloomberg BNA via e-mail. “These documents have now been taken down because our assessment is not final.”

Label Changes?

Some of the other documents the EPA briefly made public pertained to two meetings pesticide regulators held with Monsanto representatives in the year after the IARC review was published.

A slide presentation made at one of these meetings by Monsanto representatives indicated the company may be willing to make voluntary changes to the labels of its glyphosate products to address concerns that they're harming the habitats of certain pollinating insects, including the monarch butterfly.

This document, along with summaries of the discussions during the company's two meetings with EPA pesticide regulators, were among those removed from Regulations.gov.

To contact the reporter on this story: David Schultz in Washington at dschultz@bna.com

To contact the editor responsible for this story: Larry Pearl at lpearl@bna.com

For More Information

A copy of the EPA's Cancer Assessment Review Committee report on glyphosate is available at http://src.bna.com/eAi.

A brief summary of EPA's meeting March 30, 2015, with Monsanto representatives is available at http://src.bna.com/eBJ.

A brief summary of EPA's meeting June 4, 2015, with Monsanto representatives is available at http://src.bna.com/eBL.

A copy of the slide presentation Monsanto representatives made for EPA pesticide regulators last year is available at http://src.bna.com/eBx.