Kevin Hume Examiner

Marijuana Breathalyzer Not Quite Ready Yet

There is still no scientifically accepted method for determining whether someone is high on cannabis at any given moment. Sure, there are drug tests that can sample your hair, urine, or blood to determine if you’ve used cannabis — but anyone who’s taken a drug test knows that marijuana can stay in your system for as long as 30 days.

So even if you test positive for marijuana, you might have smoked that weed a month ago. Law enforcement does not have a reliable mechanism to test whether a suspect is actually high when they pull someone over. That’s a problem, since the police conduct field sobriety tests to determine driver impairment.

An Oakland company called Hound Labs has made what they claim is the “first dual alcohol & marijuana breathalyzer,” one portable device that tests for both booze and pot. Hound Labs says they intend for their new breathalyzer to be used by the law enforcement, trucking, and construction industries, and claims it could be commercially available as early as next  year.

“The Hound breathalyzer is one billion times more sensitive than today’s alcohol breathalyzers,” according to the company’s website. They say their breathalyzer “accurately identifies recent marijuana use by measuring THC in breath — where it only resides for the few hours that correlate with peak impairment after smoking.”

Despite their claim of being the “first” marijuana breathalyzer, Hound Labs is not the only company trying to develop such a thing. A Canadian company called Cannabix  Technologies claims they have a breath detector for THC that’s “under  development,” and researchers at the University of Pittsburgh also insist they have a working  prototype.

Oakland’s Hound Labs may be closer to bringing a cannabis breathalyzer to market, mainly because they’ve a lot more money to play with. That firm has received $65 million in venture capital  funding, including an investment from “Law & Order” creator Dick  Wolf.

The Hound Labs breathalyzer doesn’t measure your impairment, like the blood alcohol content measurement of a standard breathalyzer does. Instead, the company says their device can tell whether you’d smoked weed in the last few hours.

They claim this breathalyzer is sensitive enough that it can pick up trace amounts of THC on your breath for two or three hours after you’ve consumed it. On top of that, they swear it doesn’t just pick up marijuana smoke residue, but also any edibles or vape pen hits you may have taken in the “peak impairment” window of the couple hours after you’ve imbibed.

“We discovered that THC rapidly moves from blood into breath and consistently appears in breath in very low concentrations for two to three hours,” says Dr. Kara  Lynch, associate professor of laboratory medicine at UCSF,  whose clinical trials established the basis for the Hound Labs breathalyzer technology. “The ability to capture breath and measure such low concentrations of molecules represents a significant breakthrough.”

Dr. Lynch’s team did not build this breathalyzer, but their clinical findings showed that THC molecules do indeed appear in your breath for a few hours after using. This team published their findings in July in the respected, peer-reviewed medical journal Clinical Chemistry.

But that clinical trial only proved the underlying thesis that pot could be detected in breath samples for up to three hours after use. That’s not the same as saying that this Hound marijuana breathalyzer is proven to work effectively, and the breathalyzer itself played no role in their study.

And notably, everyone in the relatively small sample size of 20 study participants only  smoked cannabis. They did not use edibles or vape devices, so the claim that the Hound breathalyzer would pick up those other forms of cannabis remains unproven.

SF Weekly was anxious to blaze up and take this marijuana breathalyzer for a test ride, but the company is not letting the media test this device until it’s commercially available.

But there’s enough interest in marijuana sobriety assessment tools that it’s probably inevitable that someone is going to perfect this technology, and eventually get it into the hands of law enforcement. That day has not yet arrived, but still — if you’re too stoned to drive, take the high road and call for a rideshare.