Testing a driver for alcohol impairment is relatively easy.

Decades of research show drunken driving equals bad driving. Standardized tests mark various levels of impairment. And because alcohol passes through the system quickly, detecting its presence indicates recent use.

But determining whether someone is too high to drive is a lot more complicated.

Despite marijuana’s growing acceptance nationwide and its legality for recreational use in California, there is no consensus on how THC, its psychoactive ingredient, affects drivers or what levels constitute driving under the influence. That has left lawmakers, police and users grappling with a critical question: If you’re using marijuana, when is it safe to get behind the wheel?

An Oakland company believes it’s solved one piece of that puzzle. By mid-2020, Hound Laboratories plans to begin selling what it says is the world’s first dual alcohol-marijuana breath analyzer, which founder Dr. Mike Lynn says can test whether a user has ingested THC of any kind in the past two to three hours.

“We’re allowed to have this in our bodies,” Lynn said of marijuana, which became legal to use recreationally in California in 2018. “But the tools to differentiate somebody who’s impaired from somebody who’s not don’t exist.”

Law enforcement agencies already are testing the breath analyzers and competing roadside devices like oral swab tests. [Read More @ The San Francisco Chronicle]