Some Oregon Marijuana CO2 Extracts Contain High Levels of Possible Carcinogen


The Oregon cannabis community was rocked when The Oregonian’s Noelle Crombie released her in-depth report on the lack of standards regarding the testing of marijuana products in Oregon. Crombie, who regularly reports on all things cannabis was noticeably absent from the scene for a bit, causing many to wonder what she was up to. When “A tainted high” hit The Oregonian/Oregonlive, with the tagline “LAX STATE RULES, INCONSISTENT LAB PRACTICES AND INACCURATE TEST RESULTS PUT PESTICIDE-LACED POT ON DISPENSARY SHELVES”, we learned that the talented reporter was investigating the very essence of the medical marijuana industry–the safety of cannabis products consumed by sick and disabled patients battling debilitating medical conditions.

 The results of Crombie’s extensive report didn’t completely shock industry insiders in the know, but it certainly provided cause for concern among patients, particularly those with compromised immune systems. Fortunately, marijuana flowers, still the most popular way to utilize cannabis, didn’t contain the same high levels of pesticides and contaminants. Concentrates, such as hash oils, ever-growing in popularity, were the much bigger problem. The safety of cannabis flowers compared to concentrates and other products is one of the reasons the state is moving forward with the early sale of flowers to all adults on October 1st, but not allowing the sale of concentrates and other products.
As Crombie uncovered, some labs didn’t catch pesticides that others did and some marijuana items contained potentially harmful contaminants that weren’t pesticides. I must admit, even as someone with extensive knowledge of the cannabis industry, that I never expected to learn that products would contain “chemicals used to enhance the appearance of ornamental plants.”

Noelle Crombie reported:

The Oregonian/OregonLive shopped at Oregon dispensaries, bought cannabis that had passed pesticide tests and sent the samples to independent labs for further screening. Two labs performed the analysis: OG Analytical, a marijuana testing lab in Eugene, and Pacific Agricultural Laboratory, a Portland lab that specializes in detecting pesticides on foods and agricultural commodities. Both confirmed in blind testing the presence of pesticides that should have triggered red flags from previous labs.

Ten marijuana concentrates, popular extracts made from the plant’s leaves and flowers, were screened. Pesticides were found in nearly all of them. Many of the pesticides detected aren’t regulated by Oregon’s medical marijuana rules, which means products that contain these chemicals still can be sold.

A total of 14 chemicals were found in eight of the samples, including a half-dozen the federal government has classified as having possible or probable links to cancer.

I had heard that many dispensaries, understandably, pulled products off of their shelves and stopped trusting certain labs as the tremors and aftershocks from Crombie’s report reverberated throughout the Oregon marijuana industry. Longtime grower William Simpson, quoted in Crombie’s piece, stated that he stopped using Eagle 20 “after researching the product on his own.” It only made sense that the Oregon marijuana industry would learn from Crombie’s work and change up business practices for the better.

To do a simple, quick test on how much had changed, I stopped into the Powell House Cannabis Club, owned by William Simpson and had just a handful of products tested that were produced by prominent companies. I purchased CBD Kush and Shark Shock, both CO2 extracts processed by the CO2 Company (who weren’t tested in Crombie’s piece, I believe); Blue Dream CO2 extract processed by Golden Xtrx; and Oregon Pineapple flower grown by Simpson’s Chalice Farms. I purchased two products from the CO2 Company because one extract was in a cartridge that patients use in a vape pen and another was in a syringe, commonly used for full extract cannabis oils that patients often consume orally.

I submitted the products to OG Analytical, one of the labs that Crombie utilized. A disclaimer: I am not a doctor or a scientist and am not making any claims on the safety of these products, everyone should consult with their own doctor or physician before ingesting any products. I had the products tested for pesticides, not for THC or CBD or mold or mildew. Just as I expected after reading Crombie’s piece the cannabis flower from Chalice didn’t test positive for any alarming amounts of pesticides or residue.

The Golden Xtrx Blue Dream CO2 extract tested at 1.07 parts per million of piperonyl butoxide, a synergist that increases the potency of certain insecticides like pyrethrin. The Environmental Protection Agency (EPA) considers piperonyl butoxide as “a possible human carcinogen based on limited evidence of cancer in laboratory animals.” Checking the federal register, acceptable residue of piperonyl butoxide ranges from .1 ppm in beef to 1 ppm on eggs to 8 ppm on tomatoes, all the way up to 20 parts per million on corn.

Potentially concerning for patients, especially those with compromised immune systems, is the fact that CO2 Company’s extracts tested positive for higher levels of piperonyl butoxide than the federal government allows upon food. Again, the highest levels allowed on foods is 20 parts per million. The CO2 Company’s CBD Kush, contained in a cartridge, tested at 29 parts per million, 9 ppm above the highest levels federally allowed on food commodities. The Shark Shock CO2 extract, contained in a syringe, tested at 92 ppm, more than 4 times the amount legally allowed on food in the United States. These levels of piperonyl butoxide were higher than any tested in Crombie’s report, where the highest levels reached 24 ppm.

The CO2 Company’s Shark Shock and CBD Kush were both originally tested by Kenevir Labs before hitting the shelves at the Powell House Cannabis Club. In all fairness to Kenevir Labs, testing for piperonyl butoxide apparently isn’t required by the state and while the lab offers additional screening services above and beyond state requirements, most clients don’t want to pay the extra costs. (See comment below the blog).

I asked Todd Dalotto of CAN! Research, who graduated with an Honors Bachelor of Science in Horticultural Research from Oregon State University, about patients ingesting the 29 ppm and 92 ppm of piperonyl butoxide in the CO2 extracts and he responded via email that:

I don’t know what the safe or acute lethal doses are for human ingestion, but I attached the MSDS fyi. I would be concerned about it at any level.

It’s a major ingredient in pyrethrins & pyrethroids (insecticides).  Pyrethrins are often OMRI-listed insecticides (certified organic), but they cannot be OMRI-listed if they contain piperonyl butoxide.


Also, because CO2 has high selectivity for many contaminants and low selectivity for cannabinoids & terpenes, and because butane is the opposite, it’s more likely for it to be residual in CO2 extracts, while BHO extracts of the same contaminated material may contain little or none.

(Emphasis added)

After reading this blog Mr. Dalotto emailed me, “Glad you investigated this – it’s an issue that underlies the flaws in the current testing rules and will hopefully push the OHA/OLCC into promulgating better testing rules.  And perhaps a good research subject for OLCC Research Certificate applicants.”

The lack of lab standards led many advocates to work on new legislation and to ensure that a regulated, legalized system would mandate proper standards, something that would carry over to the medical regime. It certainly must be concerning for many patients that they can’t necessarily trust the test results of the products they currently purchase. Hopefully, upcoming rules promulgated by the Oregon Health Authority (OHA) and the Oregon Liquor Control Commission (OLCC) regarding lab standards and licensing will put into place the proper regulations that will protect Oregon’s consumers and patients, especially those most vulnerable because of their compromised immune systems. In the meantime, with some labs and companies more than others, it is definitely buyer beware.



Anthony, a longtime cannabis law reform advocate, was Chief Petitioner and co-author of Measure 91, Oregon's cannabis legalization effort. He served as director of both the New Approach Oregon and Vote Yes on 91 PACs, the political action committees responsible for the state's legalization campaign. As director of New Approach Oregon, Anthony continues to work towards effectively implementing the cannabis legalization system while protecting small business owners and the rights of patients. He sits on the Oregon Marijuana Rules Advisory Committee and fights for sensible rules at the legislature as well as city councils and county commissions across the state. Anthony helps cannabis business comply with Oregon's laws and advises advocates across the country. He also serves as content director of both the International Cannabis Business Conference and the Oregon Marijuana Business Conference, helping share the vision of moving the cannabis industry forward in a way that maintains the focus on keeping people out of prison and protecting patients. He was a member of the Oregon Health Authority Rules Advisory Committee, assisting the drafting of the administrative rules governing Oregon’s state-licensed medical marijuana facilities. He first co-authored and helped pass successful marijuana law reform measures while a law student at the University of Missouri-Columbia School of Law. He passed the Oregon Bar in 2005 and practiced criminal defense for two years before transitioning to working full-time in the political advocacy realm. His blogs on Marijuana Politics are personal in nature and don't speak for or reflect the opinions of any group or organization.