WASHINGTON— In a major victory for endangered species, a federal court ruled today that the U.S. Fish and Wildlife Service failed to adequately protect more than 1,500 imperiled species from the insecticide malathion — in violation of the Endangered Species Act.

Today’s ruling comes in response to a Center for Biological Diversity challenge of the Service’s 2022 final biological opinion on malathion, which concluded that the pesticide does not pose an extinction risk to a single protected species of wildlife or plant.

“The court’s decision is a much-needed course correction for the Fish and Wildlife Service, which submitted to the pesticide industry’s demands and hung more than 1,500 endangered species out to dry,” said Lori Ann Burd, environmental health director at the Center for Biological Diversity. “This decision will force the Service to figure out how to actually reduce harm to animals and plants from one of the worst neurotoxic pesticides on the market. That includes nearly every endangered butterfly, beetle and dragonfly we have.”

The neurotoxin malathion is part of a class of dangerous, old pesticides called organophosphates that have also been used as nerve agents in chemical warfare.

The court ruled that these “no jeopardy” conclusions were “arbitrary because the “usage” analysis underlying every determination relies on arbitrary species’ range estimates and/or pesticide usage data.” The Service ignored its own data on the size of protected species’ current ranges and relied on past information of the magnitude of malathion use that ignores location, critical to assessing effects on species.

The court also faulted the Service’s approach to assessing the pesticide’s harms to the critical habitats needed for species’ recovery. The Service eliminated many critical habitats from further analysis without looking specifically at the attributes that make the habitat critical to species conservation.

“This decision is a vital victory for thousands of endangered species at risk from toxic pesticides across the country, including many pollinators critical to our food system," said George Kimbrell, legal director for Center for Food Safety a plaintiff and co-counsel in the case. “We are gratified the court has agreed that the Fish and Wildlife Service flouted its core duties and that imperiled species will now get the protection they deserve and that the law requires.”

The Service failed to include any specific conservation measures to protect more than 1,500 listed species from malathion, only providing some on-the-ground conservation measures for 64 endangered species, including restrictions on spraying in their most important habitats.

“Poisons like malathion do tremendous damage to human health and welfare as well as the pollinators that are so vital to our food security,” said Margaret Reeves of Pesticide Action Network North America. “This ruling is a tremendous win for human and ecosystem health alike."

In 2017 scientists within the Service determined that a single exposure to malathion “could be catastrophic” and that repeated use of the insecticide could eliminate entire populations of endangered species in particular areas. The scientists also expressed alarm at the harms to the 500 threatened and endangered plant species that depend on insect pollinators for their propagation.

The 2017 scientific determination was abruptly reversed by then-Secretary of the Interior David Bernhardt during the previous Trump administration, which then dramatically weakened the processes used to assess the potential effects of malathion at the request of the pesticide industry and delayed the finalization of the biological opinion by five years.

The resulting 2022 blanket “no jeopardy” determination was a sharp contrast from its 2017 findings — from career scientists within the Service — that malathion jeopardized the continued existence of 1,284 threatened and endangered species.

However, for the overwhelming majority of species, the Service provided no meaningful restrictions on malathion’s use. For example, mosquito spraying with malathion was restricted by the Service to the hours of the day when insects are least active, but only when such limits are “feasible,” and it allows pesticide applicators complete discretion in determining what “feasible” means to them.

Background

Around 2.7 million pounds of malathion continue to be used in the United States each year. The neurotoxin is one of a number of pesticides called organophosphates that have been deployed in chemical warfare and linked to Gulf War syndrome, which causes fatigue, headaches, skin problems and breathing disorders in humans.

Today’s ruling was released by the U.S. District Court for the Northern District of California in San Francisco.