It is a criminal offence to drive within 2 hours of having a blood THC concentration of 2 nanograms per millilitre of blood or more. The penalty is higher if the concentration is 5 ng or more.

It is extremely difficult to make individual predictions about how long after smoking someone’s blood THC concentration will drop below the legal limit. No two joints are created equal in terms of THC content, and people metabolize THC at different rates depending on their genetics, age, weight, gender, and frequency of marijuana use. In one study, chronic users who smoked 1-2 joints a day had a blood THC concentration greater than 2 ng up to 6 hours after smoking a joint containing 30 mg of THC. THC metabolized more quickly in occasional users who smoked 1-2 joints a week, with their blood concentration dropping below 2 ng after about 2 hours.

To avoid legal repercussions, it is best to avoid driving for as long as possible after consuming marijuana.

If you have been charged with a DUI, it is imperative you get in contact with our team right away. Call us for free at (905) 541-2228 or fill out our free consultation form.