An Oakland company working with scientists from the University of California at Berkeley is claiming a breakthrough in the race to develop an instant roadside marijuana breathalyzer.

Hound Labs Inc, whose device is also uniquely designed to double up as an alcohol breathalyzer, is among a handful of companies and researchers hoping to capitalize on increasingly relaxed marijuana laws in the United States.

Hound Labs said on Wednesday it had found an accurate way to measure THC – the psychoactive component in cannabis – within one or two blows. The portable device is designed to help determine if a driver is impaired from recent marijuana use.

The idea is to replace a complicated assortment of costly blood and urine tests that can take days to get a result and cannot distinguish between recent and chronic use.

While 23 states have eased access to marijuana for medical use and four, plus Washington, D.C., allow recreational use, cannabis remains prohibited under federal law.

New Canadian Prime Minister Justin Trudeau has also promised to legalize marijuana for recreational use.

The National Highway Traffic Safety Administration said earlier this year that while cannabis impairs psychomotor skills and cognitive function, not enough is known about how much is needed to affect driving performance.

But some states are not waiting to reach a consensus on how much THC is too much to drive.

Washington and Montana have set a limit of 5 nanograms/milliliter (ng/mL), while Pennsylvania has a 1 ng/mL limit.

“Right now the standards are completely arbitrary. I would argue that they are useless,” Hound Labs Chief Executive Mike Lynn told Reuters, noting that existing tests cannot determine whether a person smoked an hour ago or 12 days earlier.

While Hound Labs’ device, is designed to accurately measure THC levels from smoked pot, it cannot provide evidence of impairment by itself.

“Our ability to measure THC in breath really should shift the national dialogue from one about simply detecting if THC is in someone’s body to a conversation where standards can be developed that reflect actual impairment,” said Lynn.

Hound Labs was co-founded in 2014 by former venture capitalist Lynn, who is also an emergency room doctor and reserve deputy sheriff.

The company hopes to have its product ready by the end of next year, assuming all goes well in clinical trials scheduled to begin next quarter.

Hound Labs says it will price its product at about $1,000, in line with the average alcohol breathalyzer.

Vancouver-based Cannabix Technologies Inc, Colorado-based Lifeloc Technologies Inc and a chemistry professor-PhD student duo at Washington State University are also known to be developing marijuana breathalyzers.