The Vancouver firm Cannabix claims to have invented the world’s first cannabis breathalyzer, which will be available for workplace screening and law enforcement duties. “Our intent is to test people to see if they’re impaired at the time of the test rather than whether they did it on the weekend or a week ago or two weeks ago,” said Cannabix’s president Kal Mahli.

The invention is not without issue, however. Seasoned cannabis lawyer and activist Kirk Tousaw contends, “[The] presence of THC and even the use of THC in the last couple of hours tells you only that the person has ingested THC in the last couple of hours,” adding, “It doesn’t tell you whether or not that person is impaired … if their performance is going to be affected.”

Tousaw cites hysteria around cannabis use in safety-conscious industries such as trucking and construction, and a lack of science about how cannabis impairs users — particularly medical or experienced users — has Tousaw concerned such a test could harm safe, efficient workers.

Micheal Vonn, policy director for the B.C. Civil Liberties Association, echoed Tousaw’s statements.

“The trick always with these drug recognition tests is the ability to test for actual impairment, as opposed to use,” Vonn said. “What we don’t want to see is the kind of tool that is so broad-based that it would show that someone used marijuana on the weekend, that they are a medical cannabis user and that any other kind of cannabis had been ingested that does not constitute the issue, which is impairment.”