Shawn Ellis, a managing director at NFP Ventures, sees Hound’s device as an alternative to test methods currently used across industries like construction and trucking. Those tests can’t distinguish between someone who just smoked and someone who used several days before.

“The good thing is that if it is not in your breath, then you are very unlikely to have used recently,” said Dr. Lynn.

Some companies, particularly in industries involving heavy machinery, are interested in finding a way to control staff use of marijuana, now that it is legal in 10 US states and some countries around the world.

Several drug testing methodologies exist today, and they all detect past usage of marijuana over different time frames.

Dr. Lynn explains why breath – where THC stays for just 2-3 hours after smoking – is the best way to measure recent marijuana use.

Both [blood and urine] can provide evidence that you’ve been using marijuana — so if possession or use is illegal, then the police might have a case. But if you’re in one of the 29 states that, along with Washington D.C., allow some of kind of pot use, then it’s impairment while driving they’re after.

Testing breath is the only way to determine recent marijuana use, and to correlate the resulting measurement with impairment. Hound Labs CEO, Dr. Mike Lynn, explains why this is crucial for both safety and fairness.

Dr. Mike Lynn, CEO and Co-Founder of Hound Labs, talks about the THC concentration in today’s marijuana products versus the THC content in the past, and the risks this poses.

Hound Labs CEO, Dr. Mike Lynn, explains why mixing marijuana and alcohol is so dangerous, and then questions of common sense behind the choice to drive high.

-Watch the video.