A study of cannabis alcohol testing found significant gaps in THC impairment technology.

Using a breathalyzer alone to effectively detect cannabis impairment could be a pipe dream, according to a recent pilot study led by the University of Colorado.

A valuable tool over the past half-century for law enforcement officials to measure blood alcohol levels, breathalyzers rely on chemical reactions from alcohol vapors on our breath. Despite claims to the contrary by a few alcohol meter manufacturers, recently published research in… Journal of Respiratory Research He says detecting THC weakness isn’t that simple.

Since THC can affect each person differently, detecting an imbalance isn’t as simple as using a breathalyzer, blood test, or urine sample to determine alcohol levels. Not only that, but detecting recent consumption in a regular cannabis user’s breath can be very difficult after about an hour, according to study co-author and UCLA professor of neuroscience and psychology Cinnamon Bidwill.

“We’re not there yet in terms of reliable tools, so I think making false claims or selling unreliable products is not a good situation,” she explains. “We have this image of how well a breathalyzer treats alcohol, but you have to let people make mistakes and allow places like UC Boulder to do the work. We don’t have a profit-making force in this game. We actually want to do the science and understanding Science.”

Bidwell, who has conducted cannabis impairment studies at CU in the past, partnered with National Institute of Standards and Technology chemical engineers Tara Lofstede and Kavita Jeraj to study the current effectiveness of THC’s breathalyzer technology. Armed with nearly $2 million in federal research grants, the team used a filter-based device to collect breath samples from eighteen cannabis users. Each participant was asked not to smoke or use weed the day before submitting, and to purchase a specific strain of flower containing 25 percent tetrahydrocannabinol (THC).

After securing their herbs, a CU-owned mobile laboratory was set up in a runner truck outside participants’ homes. Participants smoked or vaped cannabis in their homes and then visited the mobile laboratory to inhale a cannabis breathalyzer, with samples sent to the National Institute of Standards and Technology for analysis. According to the study, only eight of the eighteen cannabis users showed the expected increase in breath levels of tetrahydrocannabinol (THC) after cannabis use. In three samples, no THC was detected at all, while several other samples showed lower amounts of THC compared to baseline levels. While Bidwell cautions that more research is needed given the study’s small sample size, she is convinced that breathalyzers still have a lot of work to do.

More than half the country’s population now lives in states with legal cannabis, and more states continue to consider legalization measures. However, detecting weak THC has proven elusive for scientists, whose work remains restricted by the federal government due to the plant’s Schedule I status. The U.S. Department of Health and Human Services recently recommended that the DEA reschedule cannabis to Schedule III, which would allow for easier research pathways, but the DEA must first approve any rescheduling.

Colorado law currently deems any driver with more than five nanograms of tetrahydrocannabinol (THC) in their blood to be considered intoxicated. However, studies and even Western word Experiments have shown that blood levels of THC remain high for casual users for more than twelve hours after consumption, while in novice users blood levels of THC rise immediately after smoking but can drop to as little as five nanograms per day. Within hours. Colorado Department of Transportation officials and state lawmakers have acknowledged that the five-nanogram limit is not a scientifically accurate way to measure impairment, but a better alternative has not yet emerged.

In September, NIST awarded CU Boulder $600,000 to continue research into cannabis breathalyzers. Despite the findings of the CU study and the lack of universally approved roadside cannabis tests, Bidwill hopes breathalyzers can still detect recent cannabis use by drivers. However, this is only half of the equation.

“Vulnerability is different from last use,” she adds. “With blood THC levels and impairment, there’s not really a strong link. It’s not like with alcohol, where we have a really strong relationship. But even if we’re not completely sure about the impairment issue, it would be nice to have a reliable tool,” Bidwill says. To see if someone has recently used it.” “Exposure to THC does not equate to deterioration. “The link in the literature is just not there…that’s why I have to make fun of private companies that say they’ve discovered this.”

Bidwell says law enforcement officers could combine this information with roadside cognitive tests to better determine cannabis impairment rather than relying on a blood test, but adopting such protocols across the country may not be easy.

“It would be really nice if we could do this free roadside test, whether it’s an engine or reaction test — something that’s objective and quick and not dependent on the officer’s interpretation. I like the idea,” she says. “But nothing has been studied or validated to this level yet.”