DUI laws for adults set the legal limit for alcohol .08 in Washington State. This limit for alcohol is based on nearly 100 years of medical research. Every couple years, including this last legislative session, there’s talk of lowing this limit. The marijuana DUI limit is 5 nanograms of Tetrahydrocannabinol or THC. This is the chemical that produces most of the impairing effects of marijuana. Compared to the quantity of research about alcohol impairment, there is very little research about how THC levels relate to physical and mental impairment.

Legal limits allow those over 21 to legally drive after consuming a small amount of alcohol or THC. However, knowing whether you’re over the limit can be difficult. When it comes to alcohol there’s the old “one beer per hour rule.” This rule says one 12 oz standard beer (approximately 4% alcohol) per hour should keep you well under the legal limit for an alcohol DUI. Even this rule can get tricky with many modern beers being well over 4% alcohol.

There is no comparable rule for marijuana and THC. Those who consume marijuana and other products containing THC and drive in Washington State are at risk of being over the THC limit simply because there isn’t anything like a “one joint per hour rule.”

Different limits apply to the crime of Driving Under the Influence Under 21 Years of Age. This charge is often referred to as a Baby DUI. If you’re under 21 years of age, then the legal limit for both alcohol and marijuana is pretty easy. For alcohol it’s .02 and you cannot have any THC in your system if you’re under 21 years old and driving.

If you or someone you care about have been charged with DUI or any other crime, let the experienced attorneys at Cooney Law Offices guide you through the process. Cooney Law Offices. We can help!Â