skip to Main Content

Impact of the Legalization of Cannabis in Fire Safety

By Catherine Dicaire, B.Sc., Chemist

As announced by the Government of Canada, since October 17, 2018, cannabis use has been legalized in Canada. This legislative change has pushed several sectors of economic activity to reflect on the impacts of such a change in their practices and the fire safety actors are no different. Can the legalization of cannabis increase the fire rate in Québec? Ms. Catherine Dicaire, Chemist at Origin Forensic Science Inc. and former employee at Québec’s Forensic Science Laboratory, gives you food for thought on the matter.

Photograph 1

According to the statistics published on fire safety by the Ministère de la sécurité publique, there were on average 18,500 fires reported annually between 2010 and 2015, in the province of Québec. In 2015 in about 20 % of these cases, the source of heat, registered by fire prevention inspectors responsible for finding the causes and circumstances of fires, was connected to a smoker-related item or an open flame (Ministère de la sécurité publique, 2018). Can cannabis use increase these statistics?

First off, it should be known that imported cigarettes for sale in Canada or that are produced here must all be “reduced ignition potential ” cigarettes since October 2015,  when Health Canada passed a law to reduce fires caused by smoker-related items (Health Canada, 2002). In concrete terms, manufacturers can reduce the density of tobacco in the cigarettes, reduce the porosity of the paper used or add “flame retardant” additives, or reduce the circumference of the cigarettes. These actions are intended to ensure that the cigarettes do not completely burn up once lit in more than 75 % of cases (according to the ASTM method E2187‑04). As for the American manufacturers, they use a patented process consisting of applying concentric strips of paper at regular intervals over the length of the cigarette, typically called “speed bumps, which has the effect of slowing down, and even stopping, in some cases, the combustion.

Photograph 2

In addition, few studies have been done on the propensity of cannabis cigarettes to ignite. In 2016, The National Association of Fire Investigators (NAFI) published an article on its website which mentioned tests conducted to compare the incendiary potential and propensity to ignite adjacent combustible material for tobacco cigarettes vs marijuana cigarettes (Jason J., 2014). The results of this study reveal that the marijuana cigarettes tested, whether hand-rolled or pre-rolled, are less likely to burn out completely, compared to their tobacco counterparts.  It should also be noted that this propensity is directly connected to the type of cannabis used.

Indeed, cannabis is an annual plant of the Cannabaceae family native to Asia (Wikipedia, 2018). Three subspecies or varieties are found, namely sativa, indica and spontanea. They contain several chemical substances synthesized by the plant, called cannabinoids, some of which have psychoactive properties (THC), anti-inflammatory (CBD) or anti-metastatic properties. The cultivation and hybridization of different strains of cannabis allow to control the level of some of these cannabinoids in the plant. The portion of the plant that is generally consumed corresponds to the non-pollinated flower of female plants, commonly called “bud”. This flower is saturated with oil whose concentration depends, among other things, on the type of cannabis. Some of this oil is preserved during processing and ends up in the cigarette.  In addition, when a cannabis cigarette is lit, it tends to self-extinguish due to the presence of this oil which makes combustion more difficult.  Furthermore, this oil also tends to spread through the paper, once the latter is pyrolyzed, and causes the cigarette to naturally self-extinguish.

Photograph 3

Although the studies show that cannabis cigarettes have a higher tendency to self-extinguish and therefore represent a limited hazard in comparison with tobacco cigarettes, it remains clear that smoker-related items represent a significant proportion of risk factors for all fires. As a result, it is guaranteed that cannabis cigarettes will also be implicated. It must be remembered that the consumption of cannabis with high THC content affects the cognitive functions. It will therefore be more difficult to know exactly the actions of consumers before a fire if they have consumed cannabis. In addition, with reflexes being affected, cigarette butts may find themselves more often outside of ashtrays, forgotten on a couch or placed in flower pots.

In addition, the artisanal processing of cannabis is a process which requires the use of highly volatile and extremely flammable solvents, such as butane or various light petroleum distillates (lighter fluid, camping combustibles, naphtha, etc.). The transformation involves the evaporation of large quantities of solvent. These vapors then require only a suitable ignition source, such as an open flame (ex.: lighter, candle, etc.) or a spark (ex.: start-up of the refrigerator, electrostatic load, etc.) to ignite. Although it is, for the time being, forbidden to cultivate cannabis at home in Québec, one can expect a constitutional debate on the subject, and see several plants grow in the gardens of the province, the act not being considered criminal. It is therefore to be expected that the transformation of cannabis becomes the main issue in connection with the fires resulting from the legalization.


In conclusion, the legalization of cannabis will have an impact on fire safety and certainly cause a change in how the causes and circumstances of fires are found.


Ministère de la sécurité publique. (2018, 11 19). La Sécurité Incendie au Québec – Statistiques sur les incendies déclarés en 2015. Retrieved from Sécurité Publique – Québec:

Health Canada. (2002, December). A consultation Paper. Regulatory Proposal for Reducing Fire Risks from Cigarette.

Jason J., S. D. (2014). Ignition Propensity of Cannabis (Marijuana) Cigarettes. International Symposium on Fire Investigation Science and Technology, (pp. 323-334).

Wikipedia. (2018, 11 19). Cannabis. Retrieved from Wikipedia: Https://

Catherine Dicaire, B. Sc., Chemist
Back To Top