A driver above the age of 21 may not operate a vehicle if they have a minimum THC level of ____ per milliliter of blood.

It is illegal for a driver who is age 21 or older to operate a vehicle with a minimum THC level of five nanograms per milliliter of blood. A driver who is under the age of 21 may not operate a vehicle with any detectable amount of THC in their blood. The use of marijuana while driving can be extremely dangerous.