The reliability of Canada's only federally approved device for roadside cannabis impairment testing has been thrown into question after a Vancouver lawyer determined the device is easily duped, writes Calvin Hughes.

While preparing to roll out cannabis legalization in October of 2018, the Canadian government introduced a new roadside cannabis impairment testing device called the Dräger DrugTest 5000. However, a series of tests have found that it's surprisingly easy to get a false positive using the machine.

The device is supposed to be able to tell the difference between whether someone had been consuming a cannabis product with THC - the chief intoxicating compound in the plant - or CBD, the non-intoxicating cannabis compound used to treat anxiety and other medical conditions without getting the consumer high.

But the Dräger DrugTest 5000 has repeatedly failed to make that crucial distinction. For example, when a person took the Dräger test 30 minutes after consuming a CBD oil containing less than one percent THC content, they still tested positive for cannabis consumption. The Dräger is not supposed to detect CBD at all and such a small amount of THC is not supposed to trigger a positive test result either.

That's a huge problem for medical marijuana patients, who are already having trouble with roadside drug tests in Canada. Since THC can be detected in the body for extended periods of time, patients can test positive for impairment long after the intoxicating effects have worn off. And now patients can't even be sure that taking a non-intoxicating CBD-based medication will save them from getting charged with drug impaired driving.

And the problems with Dräger don't end there. Simply eating the wrong foods can lead to false positive reports of impairment by far more dangerous substances.

"We had several individuals eat poppy seed loaf from Tim Horton's and poppy seed cake they made at home. All of those people tested positive in the saliva test for opiates, and later tested positive in subsequent urine tests," Vancouver attorney Kyla Lee told Global News.

"So if a police officer were to pull those people over and gave them a saliva test, they would be arrested."

If that sounds familiar, it's because a similar situation happened in an episode of 'Seinfeld' over 20 years ago, but anyone thrown in jail for eating a poppy-seed bagel isn't laughing.

Lee and her colleagues similarly discovered that drinking certain kinds of tea can trigger the Dräger to generate a false positive as well. Having a cup of coca tea, which is derived from the same plant that cocaine comes from and is commonly available, caused a positive test result for cocaine consumption.

"That's so concerning because in our legal system, we have a zero-tolerance threshold for cocaine," she said. "Any detectable amount of cocaine in your system means you're guilty of a criminal offense."

A number of police agencies across the country have so far refused to begin using the Dräger over concerns about the reliability of the device. Lee's findings seem to prove those fears weren't unfounded.

But, if you do live in an area where police are using the Dräger, you might be in for a surprise the next time you roll up to a roadblock after getting a poppy seed bagel from Timmy's.