Hound Labs’ devices — similar in size to alcohol breathalyzers — were used in situations in which an officer suspected marijuana use or if the driver admitted to recent marijuana use. (Courtesy from Hound Labs Inc.)

The marijuana breathalyzer: When will it hit the streets?

A marijuana breathalyzer is one step closer on its road to commercialization.

Hound Labs Inc., an Oakland startup founded by an emergency room doctor/reserve deputy sheriff and a patent attorney, announced Tuesday that its handheld device that measures the presence of THC in breath successfully completed roadside field testing by law enforcement officers. The device — which was developed in partnership with scientists at the University of California, Berkeley — was designed to detect impairment from recent THC consumption via smoking pot or ingesting edibles, Reuters and others have reported.

Hound Labs CEO Dr. Mike Lynn chatted with The Cannabist on Tuesday to give an update on his company and talk on the next steps for the marijuana breathalyzer.

What the roadside tests entailed

Hound Labs’ devices — similar in size to alcohol breathalyzers — were used in situations in which an officer suspected marijuana use or the driver admitted to recent cannabis use. If the drivers performed poorly in the field sobriety tests, they were asked if they voluntarily would blow into the handheld device, which then relayed the information to the docking station to conduct the chemical analysis.

“We were not trying to arrest people,” Lynn said. “To be very specific, we were trying to educate people about (how) it’s illegal to drive stoned.”

The readings of THC levels in the breath did correlate to how recently the driver consumed marijuana, Lynn said. Drivers who failed the roadside tests were not arrested but were found a safe means home.

The only major modification required as a result of the field tests will be in the product design, he said, adding that the company is now working to make the handheld devices more rugged and durable.

Lynn declined to disclose which departments conducted the roadside tests, citing confidentiality concerns, but said the company soon will start tests with the Lompoc, Calif., police department.

“We’re going to be doing a lot more of that testing in the near future,” Lynn said.

The testing of breath, as opposed to saliva

Some of the other companies and entities developing instruments to measure THC impairment in drivers use saliva.

In Colorado, the state patrol is testing five devices as part of its marijuana oral fluid pilot program. That program is now in its second phase, Colorado State Patrol Sgt. Rob Madden said.

At Stanford University, researchers are developing a “potalyzer” to detect the presence of THC in saliva. Stanford scientists have demonstrated proof of concept, and the next step is to conduct tests in humans, said Tyler O’Brien Shultz, a member of the research team.

Lynn believes his breathalyzer product will provide a more accurate reading than fluid-based systems because THC has been shown to remain present in breath for a couple of hours. The test would correlate to recent consumption and impairment as opposed to the detection of THC’s longer-lasting presence in the bloodstream.

“It prevents the unfair arrests of people who have every right to smoke as long as they don’t get behind the wheel,” Lynn said.

But the breath approach isn’t without its critics. Carl Hart, a Columbia University professor of psychology and psychiatry, conveyed skepticism to the Atlantic, claiming that “what’s in the breath probably doesn’t represent what’s in the brain.”

What’s next

Lynn said the results from the field tests were reassuring — with readings correlating to the time frames drivers said they last consumed — but Hound Labs will continue on its path to conduct more field trials, conduct the clinical trials and amass even more data.

“It does allow us to be part of the regulatory changes that will occur down the line as the measured level starts to be correlated to actual driving impairment,” he said.

It’s a balance between safety and fairness, he said.

“It’s really that combination of making sure we get the right people off the road and, at the same time, not arresting people that aren’t impaired,” he said.

As its lab work progresses, Hound Labs plans to raise additional funding to ready the company for commercialization and a targeted product launch in the second half of 2017. Hound Labs has raised $4 million since its founding in 2014, company officials said.

The breathalyzer will be priced under $1,000, similar to alcohol breathalyzers, Lynn said.