Policy Update

Chlorpyrifos Regulation Back in the Hands of State Legislators

February 1, 2024



NCEL Point of Contact

Justin Gulino
Conservation Associate


On November 2, 2023, the Eighth Circuit Court of Appeals overturned the Environmental Protection Agency’s (EPA) monumental decision to ban all agricultural uses of the pesticide chlorpyrifos. This decision leaves states in control of regulation of the pesticide.

  • Why It Matters: Chlorpyrifos is a type of organophosphate pesticide class, one of the most dangerous chemicals used in agricultural production. Small exposure amounts frequently poison farmworkers and are linked to severe neurological developmental damage in children.

The Court’s Decision

The EPA originally restricted all food uses in response to the Ninth Circuit Court of Appeals’ 2021 ruling that found current chlorpyrifos tolerance levels were harmful to children and farmworkers. The restriction effectively prohibited all agricultural uses of the pesticide. The Eighth Circuit Court’s overturning of the previous ruling allows agricultural use to resume largely unrestricted. The merits of chlorpyrifos’s damaging health effects were not questioned by the Eight Circuit Court. Rather they objected to the EPA not sufficiently exploring if certain food uses could continue. The evaluation process now required by the EPA will likely be a yearslong effort all while chlorpyrifos remains in use.

State Action

State legislators already possess a strong history of ensuring responsible use of chlorpyrifos. Hawaii was the first state to ban the agricultural use of this pesticide in 2018 in response to a six-year long advocacy campaign based on local harm and research attributing the harm to chlorpyrifos. Since then six states (CA, HI, ME, MD, NY, OR) restricted agricultural use and six (AZ, CA, HI, MA, NJ, VT) states are considering legislative restrictions in 2024. Safe and efficient use of the pesticide is now back in the hands of state legislators across the country.