Marijuana Smoke

Why am I being warned about exposure to marijuana smoke?

  • Marijuana smoke is on the Proposition 65 list because it can cause cancer.
  • Exposure to marijuana smoke may increase the risk of cancer.
  • Proposition 65 requires businesses to determine if they must provide a warning about exposure to listed chemicals.

What is marijuana smoke?

  • Marijuana smoke is formed when the dried leaves, flowers, stems, seeds, and resins of marijuana plants (cannabis) are burned.
  • Marijuana smoke contains several thousand different compounds.  Many of these compounds cause cancer, and at least 33 of them are also on the Proposition 65 list.  These include the carcinogens arsenic, benzene, cadmium, hexavalent chromium, formaldehyde, lead, mercury, and nickel.
  • Marijuana smoke contains many of the same chemicals and carcinogens as tobacco smoke.  Marijuana may be mixed with tobacco and smoked.

How does exposure to marijuana smoke occur?

  • Pregnant women who smoke marijuana or spend time in places where marijuana is smoked can expose their baby to marijuana smoke.

How can I reduce my family’s exposure to marijuana smoke?

  • As with tobacco, avoid smoking marijuana around children and do not allow children to spend time in places where marijuana is being smoked.

For more information:

General Marijuana Smoke Fact Sheets and Resources

Scientific Information on Marijuana Smoke

Proposition 65

  • California Environmental Protection Agency (CalEPA)
    Office of Environmental Health Hazard Assessment (OEHHA)
Posted March 2017

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