Combustion of cannabis flower produces smoke—a complex aerosol containing toxic byproducts formed through high-temperature pyrolysis and oxidation. Vaporisation, by contrast, heats cannabis below the point of combustion, aiming to deliver cannabinoids and terpenes while minimising formation of these harmful compounds.
In the study, Reduction of Harmful Combustion Byproducts In Cannabis Aerosol Generated By Controlled Vaporisation Compared With Conventional Joint Combustion, mainstream aerosol generated by dry herb vaporisation and all-in-one oil vaporisation were compared with smoke from combusted cannabis joints under matched puffing conditions.
Particulate and gas-phase emissions were collected, then analysed for sixteen harmful and potentially harmful compounds (HPHCs), including benzene, toluene, p-xylene and a range of carbonyl compounds. Across all measured analytes, vaporisation reduced harmful byproducts by up to 99% compared to joint smoke.
Further analysis revealed substantially greater chemical complexity in joint smoke, including toxicants such as ethylbenzene, styrene, p-cresol and m-xylene that were not detected in vapour aerosol.
These results demonstrate that combustion—not cannabis itself—is the primary driver of harmful inhalation byproducts and that controlled vaporisation can significantly reduce exposure to these compounds.
27 June, 2026