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The California Environmental Protection Agency has announced that two state agencies are pursuing actions that could lead to increased restrictions on chlorpyrifos, a widely used agricultural pesticide.

California’s Department of Pesticide Regulation released an updated draft risk assessment for public comment last week. That action marks the start of a public and scientific review, which could result in further restrictions.

DPR scientists say that chlorpyrifos may pose a public health risk as a toxic air contaminant based on its assessment of the latest studies in the scientific community.

During the review, which could last through December 2018, the DPR is developing interim restrictions on the pesticide, and recommendations will be made to county agricultural commissioners in September. The recommendations include increasing distances between application sites and sensitive locations, such as homes and schools, and restrictions on application methods.

DPR will hold a public workshop on Sept. 15 at the Pesticide Registration and Evaluation Committee meeting in Sacramento.

Additionally, the Office of Environmental Health Hazard Assessment is referring chlorpyrifos for potential listing as a cause of birth defects and other reproductive harm under the state’s Proposition 65, which requires notifying consumers of the presence of potentially dangerous substances.

Chlorpyrifos (Lorsban) is an organophosphate insecticide, acaricide and miticide produced by Dow Agrosciences and used primarily to control foliage and soilborne insect pests on food and feed crops. In the tree fruit and grape industries, it is used during dormancy and pre-bloom to protect against certain pests, though many growers have begun to phase out use of the chemical amid questions about its safety and proposals to ban its use.

Studies have raised concerns about the safety of the chemical for those who are exposed to it. At high enough doses, chlorpyrifos has shown it can inhibit the enzyme cholinesterase, which controls nervous system signals. In 2015, under the Obama administration, the U.S. EPA proposed a ban on chlorpyrifos. However, the Trump administration reversed course earlier this year, announcing that chlorpyrifos would remain on the market. The EPA said it would continue to study the chemical.

For more information on the DPR’s process, go to http://www.cdpr.ca.gov/docs/whs/active_ingredient/chlorpyrifos.htm

For more information on the OEHHA’s process, go to www.oehha.ca.gov