Washington state cannabis regulator gives pesticide contamination update

Just Released! Get realistic market forecasts, state-by-state insights and benchmarks with the new 2024 MJBiz Factbook member program, now with quarterly updates. Make informed decisions.


Washington’s cannabis regulator provided an update on pesticide contamination in marijuana produced in the north-central area of the state, nearly two months after putting some MJ cultivators on “administrative hold” for an investigation.

The investigation began this year after random testing of marijuana grown in the area – once home to fruit orchards – detected the chemical compound DDE, which is created by the breakdown of the now-banned pesticide DDT.

Eighteen cannabis licensees are located in the “five mile stretch of land along the south end of the Okanogan River and north of Lake Pateros,” according to information presented at a June 7 Washington State Liquor and Cannabis Board (LCB) meeting.

Testing of soil samples collected in April is incomplete, but results show “levels of DDE/DDT and lead and arsenic in the soil samples are above state standards.”

Meanwhile, the LCB has received testing results for 97 out of 124 samples of water, marijuana foliage and MJ oil and rosin from the area.

Sixty-six of the 97 samples showed detectable levels of DDE, and 44 showed “DDE concentrations above (the) action limit.”

“(Twenty-four) cannabis foliage samples may rise above (the) action limit if concentrated (21 of those with DDE and 3 with other types of pesticides),” according to the LCB.

Of the five licensees placed on administrative hold, one hold has been lifted but four remain in effect.

“Holds have also been lifted on the specific products with no detectable level of DDE,” wrote the regulator.

“Holds have been lifted on product with DDE detected, but not above action limits, but further testing is required for moderate level results if the cannabis is extracted or concentrated,” the LCB continued.

“There is concern that the contaminants in the product will exceed action limits if further extracted or concentrated.”

A map of cannabis pesticide testing results has been posted online.