Washington’s Initiative 502 would allow possession of up to one ounce of marijuana for adults over age 21. The initiative would also allow 16 ounces of solid marijuana infused products or 72 ounces of liquid marijuana, as long as they are purchased in a state-licensed store. It would still be illegal to possess non-medical marijuana that is grown or purchased outside of the state. A provision on Initiative 502 allows for prosecution of drivers who have more than 5 nanograms per milliliter of active THC metabolites in their system. Current law uses the same criminal statute for Marijuana DUI, drug DUI, and alcohol DUI.

Critics of the DUI provision warn marijuana users of how easy it could be to get charged with Marijuana DUI, which would carry significant and serious criminal charges. Washington’s current DUI law is based on implied consent and per se DUI provisions. This means that if you drive on Washington roads, you have already given consent to have your blood or breath tested if you are arrested for DUI, if the officer has reasonable grounds to believe you are impaired.

I-502 will add a per se threshold for THC whereas before there was none. The law will distinguish between THC and THC-COOH. THC-COOH is the inactive marijuana metabolite known as carboxy-THC which can be used under current law to convict drivers of DUI. The initiative would only consider THC concentration in DUI cases.