Corteva Agriscience, agrochemicals subsidiary of the regrouped DuPont, is going where the US Environmental Protection Agency (EPA) and the company’s part predecessor Dow Chemical feared to tread. It has announced plans to phase out the controversial insecticide active ingredient chlorpyrifos.

The Delaware-based company, which is the sole manufacturer of the organophosphate crop protectant, sold under Dow’s Lorsban trademark, said the decision to end its production at the end of 2020 is in response to a decline in demand decline and not to public or regulatory concern.

Nevertheless, while leadership of the EPA under President Donald Trump has fiercely defended chlorpyrifos – outlawed in late 2015 by the administration of former president Barack Obama, bans enacted by important US agricultural states such as California, New York and Hawaii have eaten up a large chunk of the market.

In May 2019, after only a few months in office, California’s governor, Democrat Gavin Newsom, made good on a campaign promise and moved to prohibit the use of chlorpyrifos. The state is the leading US user of the substance that is already banned in the EU.

One of the overriding arguments against the spraying of one of the chemical industry’s most widely used the insecticides is the fear of negative effects on developing fetuses, infants and children. The American Academy of Pediatrics, with more than 666,000 members has urged its removal from the market, citing its link to low birth weight, reduced IQ and attention deficit disorders.

Corteva will accept orders through year’s end

In a statement, Corteva said it has enough supply to meet current demand through the end of 2020, and farmers who order it this year will receive their shipments. However, the company noted that demand on the whole has “declined significantly” over the past two decades.

While in 1997 organophosphates represented 40% of the global insecticide market, their share has now shrunk to 5%.  In the US, demand for chlorpyrifos currently is down more than 20% against its 1990s peak, according to the DuPont subsidiary.

Plans to end chlorpyrifos production notwithstanding, Corteva said it stands by the pesticide’s safety and efficacy and will support its defense in the 9th Circuit Court of Appeals in San Francisco, where eight states are suing the EPA.

Observers say the case, if it continues despite last week’s announcement, could well be decided in the EPA’s favor, as the preponderance of liberal judges in the 9^th circuit has been altered by new Trump appointments. The chemical is also produced as a generic, so that the outcome of the environment agency’s ongoing review could still carry weight.

Along with glyphosate, the active ingredient in Monsanto’s (now Bayer’s) Roundup herbicide, and dicamba, chlorpyrifos has been one of the most controversial agricultural chemicals worldwide, with the pros and contras often falling along political fault lines.

Reports that Dow’s then-CEO, Andrew Liveris, met with the newly elected Trump to discuss a rollback of the Obama administration’s legislation – which itself came in response to NGO lawsuits – have done their part to strengthen opposition to the chemical.

Since 2017, the EPA leadership has also stood squarely by chlorpyrifos, calling it “crucial to US agriculture.” Scott Pruitt, the agency’s first head under Donald Trump, said he had “serious scientific concerns” about the Obama ban. Trump, in turn, said he had “meaningful data and meaningful science” suggesting the insecticide was safe.