Washington State DUI laws set the legal limit for alcohol .08. This alcohol limit is based on nearly 100 years of medical research. When the state legalized marijuana, the DUI laws were also changed to add a legal limit for marijuana intoxication. This marijuana DUI limit is 5 nanograms of Tetrahydrocannabinol or THC. THC is the chemical that produces most of the impairing effects of marijuana. Compared to the quantity of research about alcohol impairment, there is significantly less research about how different THC levels relate to physical and mental impairment.

Legal limits under the DUI laws allow folks who are over 21 years old to legally drive while having a small amount of alcohol and/or THC in their body. Unfortunately, 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 no more than one 12 oz standard beer (approximately 4% alcohol) per hour should keep you under the legal limit for an alcohol DUI.

Unfortunately, there is no comparable rule for marijuana and THC. Those who consume marijuana and other products containing THC and then 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.”

It’s important to remember there are different limits for Driving Under the Influence Under 21 Years of Age or 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 there’s a zero tolerance under the law for THC if you’re driving under 21.

If you or someone you care about are facing a DUI or any other criminal charge, let the experienced attorneys at Cooney Law Offices guide you through the process. Cooney Law Offices. We can help!