With marijuana legalization one big step closer to becoming a reality in Canada, a Vancouver company says it has developed a prototype device for catching drug-impaired drivers, reports the CBC.

Cannabix Technologies president Kal Malhi says recent studies have found that THC — whether smoked or ingested — was expelled through the lungs over a two-hour period.

The challenge is putting the technology in a handheld device that can be used by police as a reliable roadside test.

Malhi says his company has been working on a new device for a year and a half that looks and works much like an alcohol breathalyzer — using technology known as high-field asymmetric waveform ion mobility spectrometry.

"We have gotten to a prototype stage and are working on getting the product out to prototype testing by third parties."

Malhi says he's already in talks with officials in places where the drug is already legal — such as Colorado — but the product still needs to undergo third-party testing for accuracy and is at least two years away from being finished.