The Zero-Tolerance Rule (Title 75 § 3802)

Under Pennsylvania Vehicle Code Section 3802(d), it is illegal to operate a motor vehicle with any amount of a Schedule I controlled substance or its metabolites in your blood. Because marijuana is technically listed as a Schedule I substance under state statute, having any trace of active THC or inactive THC metabolites (which can stay in your blood for weeks) constitutes a DUI.

Blood Tests vs. Impairment

Unlike alcohol where a 0.08% BAC threshold is used, Pennsylvania has a zero-threshold for THC. The state does not need to prove you were actively impaired while driving; they only need a blood test showing a level of THC or its metabolites of 1 ng/mL or higher to secure a conviction.

Safe Vehicle Storage & Transit Rules

If you are transporting medical cannabis from a dispensary to your home, follow these storage rules to prevent legal issues:

• Original Packaging: Medicine must remain in its original box or container with the official dispensary pharmacy receipt labels attached.
• Out of Reach: Store packages securely in your vehicle's trunk or glovebox (out of arm's reach of the driver).
• No Consumption: Under no circumstances should medication be consumed inside a vehicle. PA strictly prohibits smoking medical cannabis (vaporization only).
• No State Lines: Cannabis purchased in Pennsylvania cannot legally cross state boundaries (e.g. driving into Ohio, New York, or New Jersey), even if you have a medical card in both states. Doing so is a federal felony.