California Pesticide Regulators Say New Rules Protect Communities As Applications of a Dangerous Fumigant Rise

California regulators passed a rule in January 2024 that they said would protect communities from one of the state’s most popular, and dangerous, pesticides.

For decades, they knew that 1,3-dichloropropane, or 1,3-D, causes tumors in multiple organs in laboratory animals, which led the state to flag it as a carcinogen in 1989. Yet regulators allowed growers to fumigate fields with large volumes of 1,3-D to kill anything living in the soil before planting strawberries, almonds, grapes and other billion-dollar crops.

But now, a year after regulators implemented a rule they said would reduce cancer risk by decreasing the amount of 1,3-D in the air, applications of the highly volatile compound have spiked, state records show.