What’s the risk of second-hand cannabis smoke?

Cannabis smoke, including second-hand cannabis smoke, is harmful.  It has many of the same harmful chemicals as tobacco smoke.  Some studies have shown second-hand cannabis smoke is even more toxic to cells in your body than tobacco smoke. There is no known safe level of exposure.

If you are exposed to second-hand cannabis smoke in an enclosed space, you may find that it affects your mood and ability to think clearly, including becoming too impaired to drive. Afterwards, cannabis could be detected in your body. The amount of cannabis detected can vary according to many factors including the amount of cannabis smoke you are exposed to and how long you were exposed to it. To prevent exposure to cannabis smoke or vapour, ask those around you to consume cannabis products outdoors or in a well-ventilated area to reduce this risk.

More research is required to understand the health effects of long-term exposure to second-hand cannabis smoke.