Portland State research identifies pine rosin as a toxic additive in cannabis vaping oils
Author: Christina Williams
Posted: January 23, 2020
person vaping A new paper from Portland State University’s Department of Chemistry has identified pine rosin, a substance with well-known toxic properties, is being used as a thickening agent in cannabis oil used in vaping devices. 

Robert Strongin, a chemistry professor whose vaping-related research has been published in national scientific journals, said the pine rosin additive — also known as colophony — is prevalent in use and very toxic, possibly contributing to the vaping-related illnesses and deaths that are being tracked by the Centers for Disease Control under the acronym EVALI (for E-Cigarette and Vaping Associated Lung Injury).

To date, EVALI cases have been linked to the use of a cannabis adulterant vitamin E acetate, but the addition of pine rosin would add to the potential toxicity of cannabis oil that is used in vape pens and other vaping devices. 

“If it’s not a causative agent of the current EVALI outbreak, its high toxicity renders it a danger for future or new outbreaks,” Strongin said. 

Pine rosin fumes are a common workplace hazard released, for example, during soldering. Its inhalation leads to asthma and bronchial damage. Strogin’s research found that one puff of cannabis oil adulterated with pine rosin would deliver 3,500 times the safe level of the toxin.

Like vitamin E acetate, pine rosin is used as a thickening agent in cannabis oils. Strongin worries that with vitamin E acetate identified as a dangerous additive, manufacturers of cannabis oils might turn to alternative sources, like pine rosin, with other dangerous effects. 

“We really wanted to get the word out,” he said. 

The paper, “Pine Rosin as a Toxic Cannabis Extract Adulterant” was published online this week by  the American Chemical Society’s online press, ChemRxiv.