California Takes Action Against Pesticide Dealer for Illegal Sales

SACRAMENTO – The California Department of Pesticide Regulation (DPR) announced today it will issue a nearly $200,000 fine and take licensing action against an Idaho-based company that repeatedly broke California pesticide-sales laws.

The settlement comes after a two-year investigation into Keystone Pest Solutions. Keystone has admitted wrongdoing in two areas: selling pesticides to customers without the required permits and selling agricultural-use pesticides without verifying the required documentation for purchasers. Both are part of the strict restrictions on the use of these restricted-material pesticides. The state’s 55 county agricultural commissioners issue use permits and operator identification numbers as part of their work enforcing state pesticide laws and regulations.

“Pesticide laws exist to protect people and the environment,” said DPR Director Karen Morrison. “Keystone ignored those laws repeatedly, and this settlement sends a clear message: Companies that disregard California’s pesticide safety requirements will face significant consequences.”

The investigation into Keystone’s activities in California began in May 2024 after a routine parcel check by the Solano County Department of Agriculture. A biologist found four boxes of the weedkiller 2,4-D addressed to a person who did not have a county-issued use permit.

A month later, Solano County found another shipment addressed to a different unpermitted buyer. A full investigation found Keystone violated California restricted-material pesticides rules 159 times over a four-year period.

“California farmers, ranchers and pest control businesses adhere to strict standards ensuring pesticides are used safely and responsibly,” said Solano County Agricultural Commissioner Ed King. “In this case, Keystone was circumventing these safeguards by shipping restricted use products to unqualified individuals. Fortunately, our biologists were able to proactively intercept the pesticides and prevent unpermitted use of the products.”

Additional violations stem from information provided by the San Luis Obispo County Agricultural Commissioner in August 2025 identifying that Keystone was selling agricultural use pesticides without first asking for each purchaser’s operator ID number, which is required by law to ensure the safe handling and use of pesticides by qualified and trained applicants. Investigators later found Keystone had violated the requirement to verify an operator ID more than 1,900 times over a period of 13 months.

 San Luis Obispo County Agricultural Commissioner Marty Settevendemie said, “Violations such as this undermine those protections and pose significant risks. We greatly appreciate the cooperation of our local industry partners in bringing this issue to light and helping address a potentially dangerous situation.”

“Protecting Californians from illegal pesticide sales takes strong coordination at every level,” said Morrison. “County Agricultural Commissioners played a key role in flagging these violations, and DPR will continue to work with them to uphold the state’s pesticide laws.”

Under the settlement agreement, Keystone will pay a fine of nearly $200,000. Keystone will also serve a two-year probation during which the company is prohibited from selling or delivering any California restricted-material pesticides in the state. Additionally, Keystone’s agent in California must complete training on the state’s pesticide laws and regulations.