As the states continue to approve medical and recreational cannabis, there is growing concern about potential for increased incidents of driving while intoxicated. A fear of marijuana becoming an alcohol replacement is behind the effort to create a cannabis breathalyzer test.
Unfortunately, a recently released study conducted jointly by the National Institute of Standards and Technology (NIST) and University of Colorado, Boulder show we are no closer to developing a cannabis breathalyzer test than we were five or 10 years ago. The study shows that breath samples are too inconsistent to be considered reliable.
The Breathalyzer for Alcohol
The idea behind creating a cannabis breathalyzer test is based on the verified success of the alcohol breathalyzer. For decades, law enforcement and state courts have relied on breathalyzer tests to determine whether a driver was operating a vehicle under the influence of alcohol.
Breathalyzer tests for alcohol are pretty reliable. The results can usually be verified by blood tests after the fact. But there are big differences between alcohol and cannabis. They cover everything from substance constituents to how alcohol and marijuana are consumed.
How the Research Was Conducted
Getting back to the study in question, the NIST enrolled 18 participants who were then asked to smoke a particular brand of retail marijuana containing roughly 25% THC. The participants provided breath samples 15 minutes prior to consumption and then 60 minutes afterward.
Roughly half of the breath samples tested positive for marijuana constituents after the fact. Of the other half, some showed lower levels of marijuana constituents while others showed none at all.
In fairness, a study involving just 18 participants cannot be considered conclusive. More importantly, only 14 of the participants actually provided breath samples. This is hardly a sample that proves anything. Nonetheless, it is clear from the results that measuring cannabis extracts in the breath is not reliable.
Other Ways to Consume
Another thing to consider is that there are multiple ways to consume cannabis. Smoking is by far the preferred method among recreational users because it gets THC into the system almost instantly. But there are other options:
- Vaping and dry heating
- Gummies and other edibles
- Infused beverages
- Transdermal applications
- Tinctures and other concentrated oils.
If an intoxicated driver had used a tincture prior to being pulled over by police, perhaps an accurate breathalyzer test would pick up on that. But a breathalyzer test would be useless on another driver intoxicated by a transdermal patch.
We Have To Figure It Out
Despite the difficulty of coming up with a cannabis breathalyzer test, we need to figure it out, nonetheless. If not a breath test, some other way to measure marijuana intoxication needs to be found. With more than two-thirds of all states now legalizing medical cannabis, recreational marijuana, or both, an increase in driver intoxication should be expected.
In states with medical-only programs, like Utah, driving under the influence should be lower compared to recreational states. But even in Utah, there are concerns. According to the experts at Utah Marijuana, state law does not exempt medical cannabis users from the rules on driving while under the influence.
Could a breathalyzer test be forthcoming in the future? It is possible, but the chances are not good. Cannabis constituents can remain in the system for days or weeks following consumption. Figuring out how to measure those constituents in a way that would indicate intoxication is the big challenge. Until an accurate test is developed, law enforcement and the courts will have to rely on less scientific means to determine cannabis intoxication.