Slate’s Law Blog

Can Cannabis Breathalyzers Tell Who is Driving While Stoned?

The panic over cannabis has subsided substantially since you were in elementary school, and the guidance counselor told you that drugs are bad. It is now possible to buy cannabis legally in New Mexico as long as you are old enough to buy alcohol. The folks who have been saying that cannabis is less dangerous than alcohol have a point. Weed has never brought out anyone’s belligerent side, and while a small minority of long-term cannabis users have developed a complication that involves frequent episodes of vomiting, weed is much less likely to make you vomit than alcohol is. No matter how generally benign cannabis might be, it is not safe to drive under the influence of cannabis. Weed impairs your ability to drive safely as much as alcohol does. The difference is that it is much more difficult to measure quantitatively how stoned someone is. If you have been injured in an accident where the at-fault driver was under the influence of cannabis, contact a Santa Fe car accident lawyer.

Cannabis Breathalyzers are Useful for the Workplace, but Not for Road Safety

All police officers carry breathalyzers in their patrol cars that can accurately measure people’s blood alcohol content (BAC), and they administer breath tests at traffic stops and after accidents whenever they suspect that alcohol caused a driver to drive dangerously. The law is unambiguous about how much alcohol is too much; the legal limit is a BAC of 0.08%. BAC increases quickly as you drink alcohol and then gradually decreases as the body metabolizes one drink’s worth of alcohol per hour.

Tests that detect cannabis metabolites in the breath have existed for many years. The problem is that these tests do not measure the person’s current level of cannabis impairment. Cannabis metabolites remain detectable in your breath for weeks after the high has worn off. The body stores THC in adipose tissue and slowly metabolizes it. In other words, today’s cannabis breathalyzers cannot measure whether the driver who caused the accident smoked weed today; at best, they can tell you whether she smoked weed at any point this semester.

All of this means that cannabis breathalyzers are useful if you are an employer who requires total abstinence from cannabis. In other words, cannabis breathalyzers give you the same kinds of information you could get from testing for cannabis metabolites in a person’s urine or air. This does not provide useful evidence in car accident cases. It does not help your case if you claim that because the at-fault driver sometimes smokes weed, they must have been under the influence at the time of the accident. This claim would not even fly in a civil lawsuit, much less in criminal court. Researchers are currently working to develop a test that can measure with greater accuracy how recently a person consumed cannabis.

Contact Slate Stern About Car Accident Lawsuits

Slate Stern is a personal injury lawyer who represents plaintiffs injured in car accidents. Contact Slate Stern in Santa Fe, New Mexico or call (505)814-1517 to discuss your case.


Photo by Elsa Olofsson on Unsplash