Analysis: Pine Rosin Identified as Possible E-Liquid Adulterant

Portland, OR: A scientific analysis reveals that some adulterated cannabis e-liquid products may contain colophony (pine rosin), according to data published in the journal Forensic Science International.

Researchers affiliated with Portland State University’s Department of Chemistry analyzed a pair of unidentified adulterants provided by a cannabis cartridge vaporizer manufacturer.

The first adulterant was identified to be pure vitamin E acetate. Vitamin E acetate has previously been identified as a common adulterant in illicitly produced vapor cartridges. Last November, the US Center for Disease Control identified it as a “very strong culprit of concern” in the 2019 EVALI outbreak, which led to an estimated 3,000 hospitalizations.

The second sample tested positive for both oleamide – a psychoactive compound typically found in so-called synthetic marijuana products like Spice and K2 – and resin acids consistent with colophony. Colophony is typically used in surface coatings, lubricants, and adhesives, among other products.

Although commenters in online forums have previously speculated about the possible use of pine rosin as an additive agent in cannabis extract products, the study is the first to positively identify the presence of colophony in an oil adulterant.

Authors concluded: “The use of pine rosin as an adulterant in cannabis oil has not been previously reported in the scientific literature. … It has significant inhalation toxicity. To date, there are no reports of testing for this substance in cannabis oil samples from patients with lung injury. Due to the significant toxicity and prevalence based on social media posts, regulators and laboratory personnel should be aware of its use in adulterated cannabis oil.”

Synthetic cannabinoids, such as 5F-ADB, as well as psychoactive cough suppressant dextromethorphan, have previously been identified in unregulated, adulterated CBD oil extracts.

Full text of the study, “Pine rosin identified as a toxic cannabis extract adulterant,” appears in Forensic Science International.