Scientific Advice on Chemical Disregarded by EPA

On March 29, 2017, the Environmental Protection Agency (EPA) denied a petition requesting that it revoke all pesticide tolerances for chlorpyrifos and cancel all chlorpyrifos registrations. The denial went against the advice of top EPA scientists who, in November 2016, warned that exposure to Chlorpyrifos exceeds levels safe in many areas and thus recommended that it be banned. That recommendation was, however, overturned by EPA Administrator Scott Pruitt who questioned whether there was “sound science” of the adverse health effects of Chlorpyrifos.

Update: 

A study published in April 2018 found that EPA officials did not consult with scientists in the agency’s pesticide division before denying the petition to ban Chlorpyrifos. The study documents interviews with current and former EPA staff, one of whom said he/she had asked a colleague in the pesticide division “whether or not they had been consulted about [the chlorpyrifos decision] . . . they just said ‘nope.’”

On August 9, 2018, the U.S. Court of Appeals for the Ninth Circuit ordered EPA to ban chlorpyrifos within 60 days. A request for rehearing en banc was granted on February 6, 20219, effectively vacating the earlier ruling.

On September 22, 2020, EPA published a draft ecological risk assessment of chlorpyrifos. The assessment concluded that the "science addressing neurodevelopmental effects [of chlorpyrifos] remains unresolved." However, in conducting the assessment, EPA refused to consider several epidemiological studies that found a correlation between prenatal exposure to chlorpyrifos and developmental disorders in toddlers. EPA concluded that the studies should not be considered because the raw data underlying them was not publicly available. 

On August 18, 2021, EPA announced that it would publish a new rule banning the use of the pesticide chlorpyrifos on food. The announcement follows a 2021 court order from the Ninth Circuit Court of Appeals directing EPA to stop agricultural use of the pesticide due to decades-old science linking chlorpyrifos to brain damage. Given the court decision, EPA will not seek public comment on a draft rule (typical of the regulatory process). Instead, EPA will publish the rule in its final form unless the chemical's safety can be demonstrated within six months. Ninth Circuit Judge Jed S. Rakoff said the ruling came after the Trump-era EPA “sought to evade, through one delaying tactic after another, its plain statutory duties.” Current EPA administrator Michael Regan further commented that the agency has “tak[en] an overdue step to protect public health” in banning the use of the pesticide.