California Agency Recommends New Restrictions on Use of Chlorpyrifos

The new measures will provide increased protections from potential exposure to the pesticide while DPR completes a formal regulatory process to list chlorpyrifos as a toxic air contaminant and develops permanent restrictions on its use.

The California Department of Pesticide Regulation has recommended new interim restrictions on the use of the pesticide chlorpyrifos. The new measures will provide increased protections from potential exposure to the pesticide while DPR completes a formal regulatory process to list chlorpyrifos as a toxic air contaminant and develops permanent restrictions on its use.

DPR is recommending that county agricultural commissioners begin implementing the interim measures on Jan. 1, 2019. "DPR has been working with growers for years to find alternatives to this pesticide while also taking action to curtail its use through the regulatory process," said DPR Director Brian Leahy. "These interim measures represent a significant step in our ongoing effort to protect human health and the environment."

The interim measures include these:

  • Banning all aerial applications of chlorpyrifos
  • Discontinuing its use on most crops; chlorpyrifos will be restricted to "critical uses" on crops for which there are few if any alternative pesticides, as determined by the University of California Cooperative Extension
  • Requiring a quarter-mile buffer zone during all allowed applications of the pesticide and for 24 hours afterwards
  • Requiring a 150-foot setback from houses, businesses, schools, and other sensitive sites at all times, regardless of whether the site is occupied at the time of application

The list of recommended restrictions is available here.

Chlorpyrifos is used to control pests that threaten a variety of crops, including grapes, almonds, and oranges. Its use has declined over the past decade as growers have chosen safer alternatives -- use of the pesticide has dropped by more than 50 percent from two million pounds in 2005 to just over 900,000 pounds in 2016, according to DPR.

In 2015, DPR designated chlorpyrifos a California restricted material, meaning that only trained, licensed professionals with a permit from a local county agricultural commissioner may use products containing the pesticide, and in 2017 it was added to California's Proposition 65 list of chemicals known to cause reproductive harm. In September 2018, following extensive scientific review and public comment, DPR proposed designating chlorpyrifos as a toxic air contaminant, which California law defines as an air pollutant that may cause or contribute to increases in serious illness or death, or that may pose a present or potential hazard to human health. A 45-day public comment period on the proposed designation closed on Nov. 9.

Following designation of chlorpyrifos as a toxic air contaminant, DPR is required to consult with other state and local agencies – including the Office of Environmental Health Hazard Assessment, the California Air Resources Board, CACs, and local air districts – to determine what permanent mitigation measures are needed. That regulatory process could take up to two years to complete.

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