Concerns around roadside marijuana screening device exaggerated: manufacturer

Police in Canada have something new to add to the arsenal of tools they can use to test drivers for intoxication, and it has criminal defense lawyers across the country talking.

Justice Minister Jody Wilson-Raybould approved the Draeger DrugTest 5000 on Aug. 27, making it the only saliva screening device currently available to law enforcement for testing for THC, the psychoactive component of marijuana.

While marijuana is now legal across the country, the federal government has set the legal limit for drivers at two nanograms of THC per millilitre of blood.

Anyone caught driving with between two and five ng of THC per mililitre of blood could face a $1,000 fine. Anyone who tests over five ng or who test above 2.5 ng combined with a blood alcohol concentration above 50 milligrams per 100 mL would be considered guilty of impaired driving and subject under the existing criminal code penalties.

Rob Clark, Managing Director for Draeger Canada, explains that because DT5000 tests saliva rather than blood for roadside tests, it uses a limit of 25 ng of THC in a sample of oral fluid as a pass-fail standard.

Like roadside alcohol screening tests, the device is meant to establish probable cause for bringing a driver to a police station to test blood THC content.

“There’s two levels. There’s a screening device, and then there’s evidential,” Clark said. “Evidential for drugs is blood, and so we’re providing the screening device.”

So if a driver is found to be above the legal limit, it is the blood test results that serve as evidence, not the pass-fail outcome of the DT5000 roadside test.

A list of concerns

Experts, particularly Vancouver-based criminal defense lawyers Kyla Lee and Paul Doroshenko, argue widespread use of the device across Canada could lead to false charges, constitutional rights violations and a lot of litigation.

Lee warns that the DT5000 only works within a temperature range between five and 40 C. This, Lee says, could be problematic in parts of Canada that fall outside of that range.

“If Canadians cannot get reliable results most of the year, then the device should not be used,” Lee wrote on her personal website. “It’s useless for the stated goal of public safety, and it’s useless for protecting Charter rights.”

And Doroshenko wrote that the test has a 12 to 14 per cent false positive rate, meaning more than one in 10 people who take the test fail it, despite not actually exceeding the legal limit for THC. That false positive rate is cited in a study published earlier this year in the Journal of Analytical Toxicology.

The report looked at the use of DT5000 in the field by Norwegian police, and said that, in addition to resulting in some false positives, the median time to collect and test saliva was 50 minutes. Ultimately, though, the study said police considered DT5000 valuable tool in identifying possible impaired drivers that resulted in more than double the number of impaired driver arrests.

In statement provided to Yahoo Canada News, the Canadian Association of Chiefs of Police said the federal government consulted police services across the country in its assessment of the devices and will continue to do so.

It also cautioned that the DT5000 is only one tool available to officers in the field, and not the definitive method for catching drug-impaired drivers.

“The use of standard field sobriety testing and drug recognition experts continue to be necessary in assessing drug-impaired driving,” the statement said. “This represents a positive start, but by no means represents an end.”

Draeger responds

Since, for better or worse, law enforcement is free to use DT5000 now that marijuana is legal, Yahoo Canada News invited Clark to address some of the concerns Canadians have about the device. Here is what he had to say:

Concern: Because of its operational temperature range, DT5000 might be limited by Canadian winters.

Rob Clark: There’s two pieces to the screening device. There’s the cassette, which is the oral swab that is swabbed around the mouth to collect the saliva. And then there’s the reader that reads the result. That stays in the vehicle and that’s the piece that has the temperature requirement. And it’s the same situation with the breathalyzers today. They also have a temperature requirement.* We have experience with this device in Finland and Sweden and Russia and we’ve not had any issues with the temperature of the device.

Concern: It’s not clear whether the DT5000 tests specifically for THC or if it detects other cannabinoids like CBD, which is non-impairing and used for its medical and therapeutic effects.

Rob Clark: The device tests the THC, that’s what’s listed in the standard and that’s what it’s certified for.

Concern: The device can’t be tilted more than 10 degrees which might affect its functionality in roadside tests.

Rob Clark: The 10 degrees thing is true. This like a little mobile drug analysis laboratory that fits inside a police car. We’re just working with law enforcement at the moment and discussing the best way to manage that. It should be possible in a car. The saliva collection device is the only bit that comes out of the car, and that has no requirements for being 10 degrees. It’s only the reading device that stays in the vehicle that has the 10 degree requirement.

Concern: The manufacturer recommends a 10-minute deprivation period from eating, drinking or smoking before providing a sample. Collecting a sample can take up to 10 minutes, so the entire process can take 20 minutes or longer.

Rob Clark: That’s really an exaggeration. The same 10-minute recommendation applies also to alcohol breathalyzers, and it’s only applied if someone has been consuming food or drink in the very recent past, like they literally just stopped eating or drinking something. From that point, the average oral swab takes between 30 second and a minute to collect enough saliva for the test. The analysis itself takes four minutes.

The 10 minutes people are quoting is is based on a standard cassette that measures seven drugs at different cut-off levels. So it takes a bit longer to measure all seven drugs. At this moment of time [in Canada] we’re only measuring two drugs**, and at a higher cut-off level, so it only takes four minutes to get the analysis.

*The temperature range for the Draeger Alcotest 6810, which is used by law enforcement in Ontario, is -5 C to 50 C.

**The Draeger DT5000 only tests for cannabis and cocaine in Canada.