(Beyond Pesticides, April 7, 2020) Last week, the U.S. Environmental Protection Agency (EPA) registered a carcinogenic herbicide for new uses without following the required public notification and comment process, the Midwest Center for Investigative Reporting (MCIR) reports. The chemical in question, isoxaflutole, is a broadleaf weedkiller that can now be applied to genetically engineered (GE) soybeans in half of U.S. states. Health and environmental groups are outraged by EPA’s furtive move, accusing the agency of colluding with the pesticide industry.

“Clearly no one from the public health community knew about this because no one commented,” said Nathan Donley, PhD, of the Center for Biological Diversity to MCIR. “Yet there was all these industry comments, all these positive comments. Someone was tipped off that this docket had been opened. One side was able to comment, the other wasn’t.”

Without public notification, only 54 comments were received. In its decision document, the agency touted how most of the input “were generally in favor of the decision to register the new use.” When questioned about its move, EPA simply told MCIR that it “requested public comment on the proposed registration decision.”

The Federal Register provides the public notice of a proposed rulemaking by federal agencies like EPA, and helps ensure transparency and accountability within the executive branch. In general, agencies are required to post to the Federal Register when considering significant rule changes. There is no question EPA saw this move as significant, as it indicated in isoxafutole’s registration that it “welcomes input from the public during the decision process when registering significant new uses for registered pesticides.”

The chemical industry is pleased by the agency’s move due to rampant resistance to glyphosate and other herbicides on GE cropland throughout the country. The industry’s “solution” to this problem, touted as “resistance management,” has been to rotate a nauseating number of increasingly toxic herbicides in hopes of finding one that will take care of the problem weed.

But research from Missouri, a state where isoxaflutole was approved for use, found populations of the notorious weed water hemp resistant to six different herbicides. Although isoxaflutole was not included in the study, mesotrione, an herbicide in the same chemical class, was found to be 14 times more resistant than a susceptible water hemp plant.

A 2018 study found no evidence that rotating herbicides is an effective strategy to manage weeds. Farmers with high levels of resistance retain high weed density, no matter what new chemical are thrown at them. In fact, once a weed develops resistance to one herbicide, it is much more likely to develop resistance to other weedkillers.

Isoxaflutole is certainly not a less toxic approach to weed management. EPA lists the chemical as “likely to be carcinogenic” to humans, and its level of carcinogenicity calculated by the agency barely meets standards for approval. It is also highly drift prone, requiring EPA to impose risk mitigation measures that prohibit use not only in certain counties, but also adjacent counties in some states in order to protect endangered plants from drift. The chemical presents a significant threat to groundwater. Isoxaflutole and its breakdown chemicals have been widely detected in Midwestern streams in research published by the U.S. Geological Survey. Thus, it combines the worst elements of many widely used herbicides: the carcinogenicity of glyphosate, the drift-prone properties of dicamba, and the propensity to contaminate groundwater found with atrazine.

The chemical was recently transferred from Bayer Cropscience to BASF during the Bayer Monsanto merger, and BASF indicates the chemical will not be widely available until 2021. EPA is providing the chemical a five year registration for use on GE soybeans, indicating that use is likely to increase substantially over the next several years.

Skirting the public commenting process is concerning, and environmental groups are exploring legal options, but there are more fundamental issues at play. Federal pesticide law does not require consideration of essentiality and efficacy within its pesticide registration process; in fact, it permits EPA to completely ignore those concerns. If these requirements were written into the nation’s pesticide law, farmers would be incentivized to look to natural approaches to weed management, such as crop rotation and cover cropping, which have been found successful in the growing organic sector.

For more information on weed resistance and the dangers of GE agriculture, see Beyond Pesticides’ GE program pages.

All unattributed positions and opinions in this piece are those of Beyond Pesticides.

Source: Midwest Center for Investigative Reporting, EPA press release