The U.S. Environmental Protection Agency has approved the registration of three dicamba-based herbicides, despite previous federal court decisions invalidating earlier registrations and a growing number of complaints about the products’ safety.

The EPA approved new five-year registrations for Monsanto Co./Bayer Ag’s XtendiMax with VaporGrip Technology and BASF’s Engenia Herbicide and extended the registration for Syngenta’s Tavium Plus VaporGrip for use on dicamba-tolerant cotton and soybeans until 2025.

The registration allows the sale and use of the products as long as several control measures are followed, including the mandatory addition of a pH-buffering agent to tanks when the products are used, mandatory downwind buffer areas where some listed species are located, the simplification of labels and use directions and strict application deadlines for soybeans and cotton.

“With today’s decision, farmers now have the certainty they need to make plans for their 2021 growing season,” said EPA administrator Andrew Wheeler. “After reviewing substantial amounts of new information, conducting scientific assessments based on the best available science and carefully considering input from stakeholders we have reached a resolution that is good for our farmers and our environment.”

The news of the registrations was welcomed by farming organizations and elected officials in Indiana.

“We’re please the EPA has approved a new registration for dicamba that will allow farmers to plan for the next few years, removing a cloud of recent uncertainty,” said American Farm Bureau Federation President Zippy Duvall. “The registration demonstrates EPA’s continued commitment to using sound science to support its registration decisions and ensures farmers have access to a much-needed tool for weed management.”

U.S. Rep. Jim Baird, Indiana’s sole representative in the House Agriculture Committee or any of its subcommittees, echoed the sentiment.

“The recent EPA announcement on dicamba is good news for Hoosier farmers. This allows our agricultural community to plan and prepare with certainty for next year’s growing season. I am glad local regulators, researchers and growers provided input that resulted in a common sense solution which will benefit farmers and ensure our environment is protected,” Baird said.

The new registrations come after an EPA loss in federal court in June that invalidated registrations for XtendiMax, Engenia and a third dicamba product.

The U.S. Court of Appeals for the Ninth Circuit ruled against the EPA’s registration, saying the EPA understated or entirely failed to acknowledge the dicamba products’ risks when the agency granted them conditional registrations.

Dicamba was introduced in the 1960s, but gained in popularity in the 2010s as plants became resistant to glyphosate, another herbicidal chemical with various health risks, after decades of application.

Dicamba has been linked to an increased risk of developing several cancers, including liver and intrahepatic bile duct cancer, chronic lymphocytic leukemia and mantle cell lymphoma.

The chemical is highly soluble in water, making it extremely mobile in soil. That means it could easily contaminate groundwater, if given the chance.

Dicamba also has a tendency to drift into nearby fields, damaging crops that are not engineered to be dicamba-resistant.

The Office of Indiana State Chemist found that dicamba drift complaints from farmers increased greatly in the last decade.

Between 2008 and 2016, the yearly average for dicamba drift complaints was five. After dicamba was introduced for soybeans in 2017, the average number of complaints has risen to 153. The highest number of complaints was 185 in 2019.

The OISC instituted an application cut-off date of June 20 to limit drift incidents.

The appeals court found that EPA had minimized drift damage in its race to get the products registered.

“[T]he EPA substantially understated the amount of dicamba damage during the 2017 and 2018 growing years, characterizing the damage as ‘potential’ and ‘alleged,’ and claiming there was insufficient data from which to estimate the amount of damage. In fact, record evidence shows that [over-the-top] application of dicamba herbicides in 2017 and 2018 had caused enormous and unprecedented damage,” the court wrote.

The court ordered the EPA to cancel the registrations, which banned the sale or purchase of the products under the previous registration. The EPA also allowed farmers to use their existing stocks of the herbicide until July 31, 2020.

The new registrations will allow the sale and use of the products, although application for soybeans will only be allowed until June 30 and cotton until July 30.

The OISC’s Indiana Pesticide Review Board will hold a meeting Nov. 18 to evaluate how the new registrations and label requirements might be implemented and enforced in Indiana.