Researchers developing portable marijuana breathalyzer

Dec 2, 2014 4:14 PM by CBS Seattle

Researchers at Washington State University are developing a breath test for marijuana that would be similar to current alcohol detection methods, but would indicate levels of THC active in a driver's system.

Herbert Hill, a chemistry professor at Washington State University, is working with a research team at the university to create a device that can detect THC - the chemical behind marijuana's mind-altering effects - on a person's breath. Officers in Washington state and Colorado, where marijuana is legal, would no longer have to use blood tests to determine if the driver of a vehicle has been using the drug.

"We believe, at least initially, that it would lower the false positives that an officer would have," Hill told the Tacoma News Tribune. "They would have a higher level of confidence in making an arrest."

While the device won't initially be able to provide an exact amount of THC in the driver's system, it will show officers if there is even some active THC present to determine possible arrest or intoxicated driving charges. Follow-up test results would be needed to use such evidence in court similar to drunken driving cases.
The legal limit of 5 nanograms of THC per milliliter of blood is the threshold for the tests under Initiative 502. In 2012, 18.6 percent of blood samples taken from suspected impaired Washington drivers tested positive for active THC levels, according to the Washington State Toxicology Laboratory.

But that number increased to 25 percent of tested samples statewide in 2013 - the first year I-502 took effect.
Lawmakers have expressed public support for the research team's push to create the marijuana testing device.
"WSU is going to be at the forefront, it seems to me, of supplying this kind of science and the technology that's based on it to police all over the country," state Sen. Adam Kline, D-Seattle, told The News Tribune.

Bob Calkins, a spokesman for the Washington State Patrol, told the News Tribune that the agency would "welcome anything that will help us get impaired drivers off the road."

"It needs to be rock solid before we'll adopt it," Calkins said.

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