Cannabis (Marijuana) Smoke

Why am I being warned about exposure to cannabis smoke?

Cannabis (marijuana) smoke is on the Proposition 65 list because it can cause developmental harm and cancer.
During pregnancy, smoking cannabis or being heavily exposed to cannabis smoke can harm the development of the child. It may affect the child’s birthweight, behavior, and learning ability.
Smoking cannabis or being exposed to cannabis smoke may increase the risk of cancer.
Proposition 65 requires businesses to determine if they must provide a warning about significant exposure to listed chemicals.

Cannabis smoke is formed when the dried leaves, flowers, stems, seeds, and resins of cannabis plants are burned.

CANNABIS
SMOKE

Cannabis smoke contains several thousand different chemicals, some of which are on the Proposition 65 list. These include:
- Chemicals that can affect the baby when the mother is exposed to them during pregnancy such as THC (delta-9-tetrahydrocannabinol), which may affect behavior, learning ability, and susceptibility to drug addiction in offspring.
- Other chemicals that cause cancer and/or reproductive harm such as benzene, benzo[a]pyrene, 1,3-butadiene, cadmium, carbon monoxide, hexavalent chromium, formaldehyde, lead, mercury, and nickel.
Many of these chemicals are also in tobacco smoke, which is on the Proposition 65 list as causing cancer and birth defects and other reproductive harm.

How does exposure to cannabis smoke occur?

If you are pregnant or breastfeeding, and you smoke cannabis, your baby is exposed to many of the harmful chemicals in cannabis smoke.

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

If you are pregnant or breastfeeding, do not smoke cannabis.
Avoid spending long periods of time in places where cannabis smoke is present, especially if you are pregnant.
Avoid smoking cannabis around children, and do not allow children to spend time in places where cannabis smoke is present.

For more information:

General Fact Sheets and Resources

California Department of Public Health (CDPH)
- Let’s Talk Cannabis
- Let’s Talk Cannabis. Pregnant and Breastfeeding Women
Food and Drug Administration (FDA)
- What You Should Know About Using Cannabis, Including CBD, When Pregnant or Breastfeeding
Centers for Disease Control and Prevention (CDC)
- Marijuana and Public Health
- Marijuana and Public Health. Pregnancy
Substance Abuse and Mental Health Services Administration (SAMHSA)
- Marijuana and Pregnancy
California Environmental Protection Agency (CalEPA)
Office of Environmental Health Hazard Assessment (OEHHA)
- THC (Δ⁹-Tetrahydrocannabinol or Delta-9-Tetrahydrocannabinol)

Scientific Information on Cannabis Smoke

Proposition 65

California Environmental Protection Agency (CalEPA)
Office of Environmental Health Hazard Assessment (OEHHA)
- Proposition 65: Background
- Proposition 65: The List of Chemicals
- Proposition 65: Fact Sheets