California has announced stringent new rules on a common pesticide used in the production of strawberries, almonds, tomatoes, and peppers.

Chloropicrin is a fumigant that is used to treat the soil before crops are planted. The new rules are more stringent than those adopted by the U.S. EPA in 2012.

Under the new regulations from the state’s Department of Pesticide Regulation, farmers will be required to provide larger buffer zones when applying the chemical, and will be required to reduce the size of fields where it is applied.

Current federal guidelines allow chloropicrin to be applied to 160 acres per day. With today’s announcement, that limit is reduced to 40 acres per day, or 60 acres if impermeable tarps are used. Farmers will also be required to notify county officials at least 48 hours before a scheduled application.

Exposure to the chemical can cause eye and respiratory irritation. Regulatory agencies are split on the potential health impacts from long-term exposure to chloropicrin.

The Department of Pesticide Regulation writes:

"As part of this review, DPR considered scientific studies related to the potential carcinogenicity of chloropicrin. The World Health Organization, U.S. EPA and the European Union have concluded that chloropicrin is not likely to be a human carcinogen. However, California’s Office of Environmental Health Hazard Assessment and a state Scientific Review Panel concluded that it may be. DPR independently reviewed all of the existing research and concluded that there is insufficient evidence to establish that chloropicrin exposure causes cancer."