Last Friday, some disturbing news hit Oregon’s legal weed market: a popular pesticide was found to contain the insecticide abamectin. Rodger Voelker, of pot-testing lab OG Analytical, based in Eugene, said he discovered the issue after some growers’ samples failed their pesticide screenings, even though they claimed to have grown their pot organically. Voelker found that the farmers had all used Guardian Mite Spray, which is marketed as an organic pesticide and does not list abamectin as an ingredient (it lists active ingredients such as cinnamon oil and citric acid). Voelker tested some of the spray, detected abamectin, and alerted the Oregon Department of Agriculture.

Agriculture officials immediately removed Guardian Mite Spray from their list of approved chemicals for pot growers, and are currently conducting an investigation into the product. But the question is: Could the same insecticide be present in Washington weed? Until this issue came up, Guardian Mite Spray was on the state's list of allowed pesticides for cannabis, and it's widely popular with "organic" growers. Abamectin is not allowed for use on cannabis in Washington, according to Erik Johansen, pesticides guru at the Washington State Department of Agriculture.

Sadly, there is no required pesticide screening for pot in Washington state, although there are penalties for using pesticides that are not approved by the state. So we don’t really know.

According to spokesperson Mikhail Carpenter, the Washington State Liquor and Cannabis Board is aware of the issue and is “working with the Washington State Department of Agriculture to find a solution.” He confirmed that Guardian Mite Spray has been removed from the state’s list of allowable pesticides for pot, and that a bulletin is en route to growers.

"It's not good, but it's not the end of the world," said WSDA's Johansen, noting that abamectin is widely used in food and in livestock (although smoking poses different risks than ingestion).

Voelker suspects Guardian Mite Spray’s formula may have been recently changed, as growers were using it for some time without failing their pesticide screening, so let’s hope that any resulting recalls will be on a relatively small scale.

*UPDATE: The Washington State Liquor and Cannabis Board just released a memo announcing that Guardian Mite Spray is no longer allowed on cannabis "until further notice." The statement also includes these directives:

Producers
• Immediately discontinue use of Guardian and remove the product from the licensed premises
•Advise all processors to whom you have sold marijuana treated with Guardian that the marijuana may have been treated with an unapproved pesticide

Processors
• Provide a notice about the possible use of the unapproved pesticide to retailers who carry your products that may have been treated with Guardian

Retailers
• Post the notice provided by the processor in a conspicuous location on your licensed premises