What topics does this cannabis study cover?

This study covers research on: THC.

Where was this research published?

Published in The Analyst on April 24, 2026.

THC

Toxic breakdown products found in popular acetylated cannabis vapes

Effect of O-acetylation on ketene and carbonyl yields from conventional and emerging cannabinoids.

The Analyst • April 24, 2026 • Moderately Relevant

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AI Summary

This study examined the safety of vaping acetylated cannabinoids—a growing category of cannabis products sold commercially. Researchers tested popular cannabinoids including delta-8-THC, delta-9-THC, CBD, and CBG, along with their acetylated versions, using a standard cannabis e-cigarette. They discovered that acetylated cannabinoids break down into ketene, a toxic compound previously found in contaminated vaping products that caused serious lung injuries. The acetyl groups decomposed with nearly 99% efficiency into ketene during vaping, while non-acetylated forms produced no ketene at all.

The findings revealed concerning toxicant exposure levels. Ketene yields ranged from 1-4% by cannabinoid mass, while carbonyl compounds ranged from 0.1-1.5%—production levels that can exceed established safety limits for lung health. CBD-di-O-acetate produced the highest toxicant load, likely due to its chemical structure with multiple acetate groups. The researchers also found that vaping technique matters: opening the device's air vents reduced ketene but increased other harmful carbonyl compounds, meaning users could unwittingly shift their toxic exposure patterns depending on how they inhale.

These results raise significant public health concerns for consumers of emerging acetylated cannabinoid products, which have flooded the market with limited regulation. The study demonstrates that product chemistry directly impacts user safety, and stricter regulation of acetylated cannabinoid products is essential to prevent the health consequences seen in previous vaping-related lung injury outbreaks. The research underscores the need for transparency in product formulation and better safety standards across the cannabis industry.

📄 Original Abstract

The pulmonary toxicant, ketene, has been observed from electronic (e-) cigarette vaping and dabbing (flash vaporisation) of acetylated compounds such as Vitamin E Acetate (VEA) and the O-acetates of select few cannabinoids. Yet for the majority of commercially-available cannabinoids with structural similarities to VEA, toxicant yields from vaping have not been quantified. Methodology optimisation for ketene trapping and quantification or characterisation of the co-production of other potentially harmful products have not been reported. In this work, an optimised impinger collection method was used to quantify the yield of ketene and carbonyl products from several conventional and emerging cannabinoid distillates using a commercially available cannabis e-cigarette. Ketene and carbonyls were analysed after chemical derivitisation by high performance liquid chromatography high-resolution mass spectrometry (HPLC-HRMS) and cannabinoids were analysed using gas chromatography mass spectrometry (GC-MS). The cannabinoids under study are: delta-8 tetrahydrocannbinol O-acetate (Δ8-THCO), delta-9 tetrahydrocannbinol O-acetate (Δ9-THCO), cannabidiol di-O-acetate (CBD-di-O), cannabigerol di-O-acetate (CBG-di-O), 9(R)-hexahydrocannabinol O-acetate (HHCO) and their paired non-acetylated analogues (Δ8-THC, Δ9-THC, CBD, CBG, and HHC). The acetyl group decomposed into ketene during vaping with nearly quantitative efficiency (>99%). No ketene was observed in the unvaped distillates or during vaping of the the non-acetylated cannabinoids. The highest summed production of ketene and carbonyl was observed from CBD-di-O which was attributed to the presence of two O-acetate groups on the phenyl moeity and the reactive exo-cyclic double bond of the terpene side chain. Higher airflow through the device due to opening the vent reduced ketene yields but increased carbonyl yields, showcasing that temperature and oxygen influence the distribution of these toxicants. Cannabis vape users can oscillate between open and closed air vents, which modify their toxicant exposure. Overall, ketene and carbonyl production yields from O-acetylated cannabinoids ranged between 1-4% and 0.1-1.5%, respectively, by cannabinoid mass. The carbonyl production yields for non-acetylated cannabinoids ranged between 0.1-7% by cannabinoid mass. These optimised measurements show that vape users can be exposed to yields of toxicants that far exceed safety limits for pulmonary effects, and therefore, further stringent product regulation is required to avoid health implications from vaping.

Paper Type

📄 Research

Publication

Journal: The Analyst
Published: April 24, 2026
PMID: 42029062
DOI: 10.1039/d6an00190d

Authors (6)

Rhianna L Evans Department of Environmental Toxicology, University of California, Davis, 95616, CA, USA. tbn@ucdavis.edu.
C Noel Corley Department of Environmental Toxicology, University of California, Davis, 95616, CA, USA. tbn@ucdavis.edu.
Haylee C Hunsaker Department of Environmental Toxicology, University of California, Davis, 95616, CA, USA. tbn@ucdavis.edu.
Sascha C T Nicklisch Department of Environmental Toxicology, University of California, Davis, 95616, CA, USA. tbn@ucdavis.edu.
Allison K Ehrlich Department of Environmental Toxicology, University of California, Davis, 95616, CA, USA. tbn@ucdavis.edu.
+1 more authors