A week after the federal public safety minister announced which testing device will be approved to test marijuana-impaired drivers, a Vancouver lawyer is pointing out its flaws on the device itself.

Police agencies across the province still don’t know when the $6,000 Dräger Drug Test 5000 will start arriving for testing, but defence lawyer Paul Doroshenko has been putting it through its paces.

“In our testing, it’s four minutes of swabbing to get enough saliva for a test,” explained Doroshenko.

But in a demonstration for local media, a legal assistant gathered enough saliva to turn the indicator section blue in just under a minute. The testing units are vacuum-sealed in packaging that displays an expiry date and outlines the conditions it needs to be kept in, namely temperatures between four and 30 degrees Celsius.

Doroshenko then inserted the swab, which comes on a plastic handle, into the machine, which took 10 minutes to analyze the sample.

Considering the manufacturer recommends the test be conducted only after ensuring 10 minutes has passed since the test subject has consumed anything, the entire road-side test can easily take 24 minutes.

"Then [if] you end up with a false positive for cannabis, they take you back to the detachment and run you through the drug recognition evaluation, which is going to take you an hour, hour and a half," he points out.

That opens the machine to legal challenges for the length of time it takes to investigate someone on suspicion of driving high – not to mention the questions around the machine’s efficacy.

European jurisdictions have found error rates between 12 and 15 per cent, but Australian police found a whopping one-third of all tests could be false positives, calling the device into serious question.

The federal government approved the swab-testing devise for use by Canadian police agencies last week amid criticism. 

The units can confirm the presence of THC, the main psychoactive component of marijuana, but don’t necessarily determine impairment. Marijuana will be fully legalized on Oct. 17, months later than the federal government had planned, based on appeals from police groups asking for more time to plan for enforcement of the law and screening for impaired drivers.

The RCMP tells CTV News, despite the incoming Dräger units, “the use of Standardized Field Sobriety Test training and Drug Recognition Experts will continue to be the primary enforcement tools against drug-impaired drivers.”

Vancouver police say they have been using the SFB test with their own trained DREs, but wouldn’t say when they expected to receive the devices.

“The VPD is aware of the new roadside screening device authorized by the Federal Government. We expect an update from Police Services, here in B.C., regarding next steps.”

Lawyers like Doroshenko are ready to fight roadside driving prohibitions and charges stemming from the Dräger, which could take months to refute via blood-testing that follows the roadside test.

“Our concern is you're going to wait six to eight months for a result that exonerates you, meanwhile you're charged with being impaired by drugs. It's hugely stigmatizing."