US farm groups press EPA to reregister chlorpyrifos

19:35 PM | April 7, 2021 | J R Pegg

The American Farm Bureau Federation and more than 30 other ag groups are urging the Biden administration not to ban chlorpyrifos, warning that failure to renew the registration of the organophosphate insecticide “could lead to catastrophic yield losses” for growers across the US.

A joint letter sent to the EPA by the Farm Bureau and its allies argue that chlorpyrifos is a “critically important” crop protection tool that can be used safely, adding that alternatives are inadequate and costly. They also contend that the EPA has overestimated the potential harm from exposure to very low levels of chlorpyrifos via food and drinking water, while also underestimating the economic benefits to farmers.

The insecticide’s effectiveness against a broad class of insect pests, including some that have become resistant to other insecticides, has made it “one of the most popular and effective tools for agricultural producers in the United States”, the groups say in their letter. “EPA should consider carefully and establish with a strong level of confidence any genuine risks before considering any actions that might result in growers losing access to this critical tool.”

The groups signing the letter range across the agriculture supply chain, including the Agricultural Retailers Association, the American Seed Trade Association and groups representing pesticide applicators, crop consultants and groups representing apple, citrus, corn, cotton, potato, rice, sorghum, soybean, sugarbeet, and vegetable growers.

The development comes little over a month after fruit, vegetable and sunflower growers approached the EPA echoing similar sentiments.

Waiting for Biden

The input from the farm groups comes as the Biden administration is reviewing the EPA’s decision to reject a petition filed by environmentalists to revoke food tolerances and cancel registrations for chlorpyrifos because of concerns about potential neurological harm to children and farmworkers. The EPA was prepared to grant the petition in the final year of the Obama Administration after finding cumulative exposures to the known neurotoxin exceeded the safety standard set by federal food safety law.

But pressure from farm groups and the pesticide industry helped convince the Trump Administration to change course and deny the petition. Then-EPA Administrator Scott Pruitt cited uncertainty about the health risks from chlorpyrifos and touted the benefits of the insecticide for agriculture. US farmers use an estimated 5 million pounds (2,268 metric tons) of the insecticide on more than 50 crops, including soybeans, alfalfa, almonds, apples, citrus fruits, maize and strawberries.

The EPA subsequently issued new risk assessments in September 2020 and proposed an interim reregistration decision last December to allow continued uses. The proposed interim decision includes new mitigation measures, including label amendments to address drinking water contamination and spray drift as well as additional application restrictions and requirements for workers to use personal protective equipment. Those restrictions were prompted by the EPA’s decision to apply a 10x safety factor to ensure children are protected from cumulative exposures, a move the Agency said was made because of uncertainty about health effects.

Farm groups say risks overstated

The petitioners contend that there is no need for the 10x safety factor and caution that the EPA should not rely on epidemiological data from prenatal exposure studies conducted by US Columbia University researchers. Those studies focused on inner city mothers and children accidentally exposed to the insecticide, which was registered for household use until 2001, and raised concerns about neurological harm. The EPA says that the research is a “significant motivation” for using a 10x safety factor, but critics have questioned the small sample size of the studies and say that the EPA is giving it too much weight, thereby overstating the risks from chlorpyrifos.

Other epidemiological studies “seem to point to little or no correlation between neurodevelopmental disorders and chlorpyrifos or organophosphate exposure”, according to the agriculture groups. “This line of evidence suggests it would be irresponsible to discontinue registered uses on chlorpyrifos based on conflicting, tenuous epidemiological data.”

The letter states that the “risks and alleged risks that EPA has based much of this registration review around are in many instances inconclusive and tenuous” and the evidence referenced by the Agency does not support switching to a 10x safety factor.

“Nor does it currently warrant restricting, discontinuing grower access to, or canceling the registration of this vital chemistry,” the Farm Bureau and allies say. “While we do encourage EPA to continue to research the validity of these potential risks, we strongly support the reregistration of chlorpyrifos using a 1x FQPA safety factor, and in a way that preserves existing uses for agricultural producers.”

The urging from the farm groups may help convince the EPA to press on with the proposed interim decision, but the White House is facing substantial pressure from environmentalists, farmworker advocates and public health groups to ban chlorpyrifos.

Controversy surrounding the insecticide has been growing for more than a decade and the legality of the Trump Administration’s decision not to ban chlorpyrifos is currently under consideration by the US Court of Appeals for the Ninth Circuit. Five states—California, Hawaii, Oregon, Maryland and New York—have moved to ban agricultural uses within their borders and Democrats in the Congress have written legislation to force the EPA to follow suit.

The EU banned chlorpyrifos last year and intends to propose a global prohibition on production and use via the Stockholm Convention on Persistent Organic Pollutants later this year.