THC is the main psychoactive ingredient in marijuana. In Washington State, a driver who is at least 21 years old can be arrested for driving with a THC level of _____ nanograms per milliliter of blood or higher.

THC is the main psychoactive ingredient in marijuana. In Washington State, a driver who is at least 21 years old can be arrested for driving with a THC level of _____ nanograms per milliliter of blood or higher.

• A. 5.00
• B. 4.00
• C. 3.00
• D. 2.00

Answer: (A)

In Washington, a fixed threshold is used to help enforce marijuana DUI laws. For drivers 21 and older, having five nanograms per milliliter of THC in the blood is the per se limit. That means once the blood test shows five or more ng/mL, law enforcement can arrest for driving under the influence based on that measurable level, regardless of how the driver seems to be performing. This objective standard helps authorities determine impairment more consistently. If the level is below five ng/mL, an arrest can still happen if there’s clear evidence of impairment, but the per se rule itself applies specifically at five ng/mL and above. The other numbers listed are not the official per se limit.

In Washington, a fixed threshold is used to help enforce marijuana DUI laws. For drivers 21 and older, having five nanograms per milliliter of THC in the blood is the per se limit. That means once the blood test shows five or more ng/mL, law enforcement can arrest for driving under the influence based on that measurable level, regardless of how the driver seems to be performing. This objective standard helps authorities determine impairment more consistently. If the level is below five ng/mL, an arrest can still happen if there’s clear evidence of impairment, but the per se rule itself applies specifically at five ng/mL and above. The other numbers listed are not the official per se limit.