Canada Cannabis Driving Laws: THC Limits and No Safe Wait-Time Rule
Federal THC offences
Justice Canada describes Criminal Code offences for having specified blood THC concentrations within two hours after driving: 2 ng/mL or more but less than 5 ng/mL, and 5 ng/mL or more. A separate offence addresses a combination of THC and alcohol. These are legal offence thresholds, not a personal safe-to-drive test; impairment can occur below them.
Why there is no universal wait time
Justice Canada says the evidence does not provide general guidance on how long a person should wait after cannabis before driving. Effects vary. Do not use a clock or feeling mostly normal as a guarantee; arrange another ride if you have used cannabis and may be impaired.
Provincial and territorial rules
Provinces and territories may add consequences, including special rules for novice drivers. Check the official rules where you will drive. Medical authorization does not exempt drivers from impaired-driving offences.
For a broader legal overview, see Canada's cannabis laws and border rules.
Quick FAQ
Is there a fixed number of hours to wait after cannabis before driving?
No. Justice Canada says there is no standard wait time; effects vary. Do not drive if impaired.
What federal THC limits apply?
Justice Canada lists offences for having a blood THC concentration of 2 to under 5 ng/mL or 5 ng/mL or more within two hours after driving, with a separate combined cannabis/alcohol offence. These are legal thresholds, not a personal safe-use calculator.
Do provincial rules also matter?
Yes. Provinces and territories may have additional rules and penalties, including for novice drivers. Check the official rules where you will drive.
Sources
- Justice Canada: Drug-Impaired Driving Laws FAQ -- checked 2026-09-25.
- Health Canada: Cannabis impairment -- checked 2026-09-25.