A few years back, the cannabis breathalyzer was invented. Like alcohol breathalyzers, this device will be able to detect the amount of THC on a driver’s breath to see if he/she is too impaired to drive. Now, in California police have begun testing a bud breathalyzer called “The Hound” on drivers.
VICE‘s Madison Margolin interviewed Hound Labs CEO Mike Lynn abut the device:
Unlike breathalyzers that may simply detect the presence of THC, the Hound Labs device detects the levels of THC in parts per trillion. “That gives us a very precise amount of THC in the breath. That number, that measured level will ultimately be correlated to driving impairment at roadside,” Lynn said. “Any legislation related to impairment needs to reflect true data.”
It’s not clear exactly how much THC, the main psychoactive compound in cannabis, leads to impairment, but one study showed that drivers under the influence of marijuana had increased weaving with levels 13.1ug/L (micrograms/liter) THC.
In the next phase of testing, people will be given marijuana and then asked to drive around a safe, enclosed space so researchers can determine at what level impairment begins. THC in the breath only shows up within about the first two hours after people smoke, Lynn explained. “You can smoke every day, but if you haven’t smoked for a few hours we’re not going to detect it and measure it. That’s the time period that correlates with maximum impairment,” he said.
“It’s critical for protecting people who have the legal right to smoke cannabis. Whatever you did last night shouldn’t frankly impact you getting arrested the next morning if you’re not impaired. That’s the problem with urine, blood, and saliva tests.”
Under the current model, if a driver is pulled over for seeming impairment, but doesn’t test positive for alcohol, police officers can still make an arrest and order a THC test. In most places, if you refuse to take the test, you can lose your license for a year. Experts usually advise that if you haven’t used marijuana for at least three days, to choose the blood test, usually the most accurate, because THC is detectable in the blood for up to two days. Otherwise, they often say to choose a urine test because it shows THC from up to 35 days prior. But even so, detecting THC alone is not enough to prove impairment, which is required for DUI convictions.