Marijuana breathalyzer aims to detect high drivers 'without unjustly accusing'

Lilly Price | USA TODAY

Corrections & Clarifications: An earlier version of this article misstated how the device detects THC and wrongly characterized Cannabix Technologies' product.

A breathalyzer able to determine if a driver smoked pot could roll out in select cities in the fall, according to a company developing the first-of-its-kind product.

With recreational weed now legal in nine states and the District of Columbia, California-based Hound Labs Inc. has created a marijuana-breathalyzer it says will make roads safer and hold drivers accountable. The company claims the device is hypersensitive, allowing it to pick up any THC — the psychoactive ingredient in marijuana — potentially present on drivers' breath.

"The Hound breathalyzer is 1 billion times more sensitive than today’s alcohol breathalyzers," the company says on its site.

A 2017 survey by the Colorado Department of Transportation (CDOT) found that almost 70 percent of cannabis consumers drove high at least once in the past year. Twenty-seven percent said they drive high almost every day.

Currently, officers who suspect a driver is impaired can only test the hunch with field sobriety tests. Blood, breath or urine samples could be taken to determine if a driver is high, but such tests can be inaccurate. Those tests also detect if the driver was high that day or week, rather than if they were high while operating the vehicle in that instance.

Tools such as Hound Labs' alcohol-and-marijuana breathalyzer or Canadian company Cannabix Technologies Inc.'s THC breathalyzer aim to present an objective determination of recent marijuana use rather than one based on an officers' judgement or an intrusive test. Drivers with a blood alcohol concentration above .08 percent are considered under the influence of alcohol or driving while impaired. But what exactly qualifies a driver under the influence of marijuana as "impaired" is up for debate in the science community.

For Hound Labs' breathalyzers, that qualification is marked by timing. Though the company's breathalyzers can determine how much marijuana is in someone's breath, the actual level of THC is not as relevant as recency of use for determining whether an individual is high, according to their research.

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THC only stays in breath during the "peak window of impairment," about one to two hours after smoking marijuana, according to Hound Labs. The level of THC found in breath samples drops to zero at three hours after smoking, the company's research found.

When an individual blows into the breathalyzer, it can determine within a couple minutes whether there is alcohol, THC or both in the person's system. Since THC is only present in someone's breath during that peak two-hour window, the driver is considered impaired when it's detected.

The breathalyzer would then display "Warning" if THC is detected and "Pass" if it is not.

The device "will help ensure safety on our roads and in the workplace while also promoting fairness to people who use marijuana legally and responsibly," said Louisa Ashord, marketing manager for Hound Labs in a statement.

Follow Lilly Price on Twitter: @lillianmprice