As of December 1, 2012, people in the state of Washington are allowed to possess up to 1oz of marijuana for personal use. In addition, the new law set a “per se,” or maximum, threshold THC level that drivers cannot exceed while driving.
Before the passage of I-502 which legalized marijuana, Washington had a zero-tolerance policy regarding driving under the influence of marijuana’s active ingredient, delta-9 tetrahydrocannabinol (THC), which many believe impairs driving ability. Prior to the law’s effective date of December 1, 2013, any level of THC in a driver’s blood was prohibited. Furthermore, drivers under the age of 21 were prohibited from having any active THC in their blood. Now, drivers 21 or older are permitted a very low amount of the active THC in their blood—up to 5 ng (nanograms) per milliliter of blood. Driving under the influence of more than 5 ng per milliliter of blood is punishable by law.
There is much controversy over whether any particular driver will be impaired by 5 ng of delta-9 THC. Even the National Highway Traffic Safety Administration (NHTSA) has published materials that cast doubt upon the fairness of establishing a bright line “per se” level of impairment. In their 2004 publication Drugs and Human Performance Fact Sheets, the authors state that it is “difficult to establish a relationship between a person’s THC blood or plasma concentration and [driving] performance impairing effects. . . .concentrations of the parent drug [marijuana] and the metabolite [delta-9 THC] are very dependent on patterns of use as well as dose.” Thus, they conclude that “it is inadvisable to try and predict effects based on blood THC concentrations alone, and currently impossible to predict specific effects based on THC-COOH [inactive THC metabolite] concentrations.”
The reason for this is that people become tolerant to any drug, including THC, after time. Thus, an individual may have a seemingly high level of THC in their blood, but not be too impaired to drive. In fact, in 1983, NHTSA published Marijuana and Actual Driving Performance, where they concluded, “THC’s adverse effects on driving performance appear relatively small.”
Everyone reacts to marijuana differently. If the driver in question did not drive in an impaired manner, the jury can reject a prosecutor’s case and find the driver not guilty.
It is a common mistake to believe that if your breath or blood alcohol concentration (BAC) is under 0.08 percent, or below the new 5 ng/ml limit for THC, you cannot be convicted of a DUI. This is incorrect. The 0.08 and 5 ng/ml limits allow, but do not require, the jury to presume you are impaired at those levels or higher, regardless of whether the driver was actually impaired. But even when a driver is under those limits, they may still be convicted of a DUI under the “affected by” element if the prosecutor can prove that less than 5ng of THC caused the suspect’s ability to drive to be impaired to any appreciable degree. This means that if you are in an accident or are pulled over for driving erratically, you may still be convicted of a DUI while under the legal limits because the jury may conclude that even a negligible amount of THC impaired your driving.
If you have been arrested for a marijuana-related DUI offense, the highly trained and successful Washington DUI lawyers at Callahan Law, P.S., Inc. are available to aggressively defend you. Call us today at (253) 252-5841.