KUSA – Researchers from Washington State University are working to develop a breath test for marijuana.
The test would be similar to current alcohol breath tests used by police.
WSU chemistry professor Herbert Hill said existing technologies used by airport security and customs agents to detect drugs can be repurposed to test breath for THC. THC is the psychoactive component of marijuana.
Amendment 64 set five nanograms of active THC-per-milliliter of blood as the legal limit a driver is deemed to be impaired.
Hill said the marijuana breath test probably won’t be able to pinpoint the level of THC in the body, but it will tell law enforcement that some active THC is present.
Hill said the breath test could be helpful to officers as they decide whether to arrest a suspected impaired driver.
“We believe, at least initially, that it would lower the false positives that an officer would have,” Hill said. “They would have a higher level of confidence in making an arrest.”
Law enforcement officers would still have to get follow-up test results to use as evidence in court, just as they do in drunk driving cases.
Professor Hill and his team plan to finish lab tests of a prototype marijuana breath test this year, then begin testing human breath next year.
After that, researchers plan to test the device in the field.