DENVER -- A California lab is creating quite the buzz with a new Breathalyzer that can detect alcohol and marijuana when someone exhales.
When it comes to being able to tell if someone has smoked marijuana recently and if they are stoned, breath is much better than urine or blood tests.
THC, the part of marijuana that makes people high, can linger a long time in bodies, sometimes for days and even a month.
So authorities cannot use blood and urine tests to determine if someone has recently smoked marijuana because they can't tell how long it has been.
The new device based on someone's breath can do just that. Matt Francis, a chemist at the University of California Berkeley, has spent the past 18 months developing the device.
"We had to develop some new chemistry that can actually be done," he said. "It was not obvious when we started that we could tag this."
Most law enforcement officials can determine when someone is impaired. But Sgt. David Dowty with the union that represents California Highway patrolmen said being able to make an arrest and being able to get a conviction are different things.
"Because they don't have a tool, like with alcohol, it's very difficult for them to say, 'OK. All these things that you saw ... and you may be right, officer. But we need to be able to convince a jury," Dowty said.
The breath test can detect alcohol and marijuana when the person taking it exhales. And that's important because there are already plenty of ways to tell if someone uses marijuana.
But to tell if someone smoked marijuana recently or if they are stoned, breath is much at detection.
While Francis has worked on the problem, Mike Lynn, the CEO of Hound Labs, has been working on it for much longer.
"We have tremendous interest from not only law enforcement, employers who are struggling with this problem, but also the cannabis industry who knows you can't be driving stoned," Lynn said. "Everybody really accepts that."
Lynn argues the Breathalyzer will be the best defense for marijuana users who aren't stoned at the time they are driving but get pulled over anyway.