Excellent topic and revolutionary for those who care about their health as vaporization is aimed at suppressing respiratory toxins. This is done by heating cannabis to a temperature where cannabinoid vapors form (typically around 180-190°C), but below the point of combustion where smoke and associated toxins are produced (near 230°C). Of particular concern are the carcinogenic polynuclear (or ??polycyclic?) aromatic hydrocarbons (PAHs), known byproducts of combustion that are thought to be a major culprit in smoking-related cancers. One study showed vapors were found to consist overwhelmingly of cannabinoids (good stuff), while the combusted control contained over one hundred additional chemicals, including several known PAHs (really bad stuff). Another study, upon analysis, found the vaporizer delivered THC while completely eliminating three specific toxins (naphthalene, benzene and toluene) in the solid phase of the vapor. What amazes me the most, is how many compounds are present in an gaseous analysis of combusted cannabis. These are reduced to a handful of trace amounts when vaporized. While more research is needed, as of know it appears there is no reason why holding your breath filled with vapor would cause any perceivable harm.


Fehr, K.O. and Kalant, H. 1972. Analysis of cannabis smoke obtained under different combustion conditions. Can J Physiol Pharmacol 50: 761-7.

Perez-Reyes, M. 1990. Marijuana smoking: factors that influence the bioavailability of tetrahydrocannabinol. In C.N. Chiang and R.L. Hawks, eds. Research Findings on Smoking of Abused Substances. NIDA Research Monograph 99:42-62.