In search of a reliable cannabis breathalyzer

Researchers at Washington State University in Pullman are currently conducting a study to develop a «breathalyzer» that reliably detects cannabis use.

Unlike alcohol, whose blood level accurately reflects consumption, cannabis is much more difficult to assess. A daily user can have THC in his blood without being under the influence. He will therefore be detected as positive, despite the fact that he may not have smoked in the last 12 hours.

Washington State was one of the first US states to legalize cannabis in June 2014, so it's no stranger to the problem. The blood THC limit for driving has been set at 5 nanograms of THC. Beyond that, drivers are prosecuted for driving under the influence of cannabis. Nathan Weller, city councillor and research assistant, is working on this new rapid detection technology. «We're trying to create a tool for law enforcement and businesses to detect whether someone is under the influence of alcohol or cannabis,» he explains.

To ensure that none of the study participants drive under the influence of cannabis, cabs will take them directly to the University. Volunteers must, of course, be aged 21 or over and residents of Pullman. The test is carried out as follows: after preliminary formalities including a blood test and mouth swab, participants can obtain supplies from a state-licensed dispensary and freely consume weed, while being paid 30$ per hour. The scientific team then set about studying how to effectively test participants' consumption.

Nathan Weller assures that if the test is a success, a big step would be taken in the cannabis industry. «Research like this is being done all over the world, not just in the US,» he said.

This study is sponsored by Washington State Department of Social and Health Services and should be completed by mid-June.

Mehdi Bautier