I have written a couple of articles describing why marijuana breathalyzers are built on junk science. For starters, there's yet to have been solid trials of any marijuana breathalyzer out there right now, so it's debatable whether such a device can even detect marijuana on someone's breath at all. And even if one can, that leads to another flaw to the marijuana breathalyzer idea - just because someone has marijuana on their breath doesn't mean that they are impaired at the time of the test.
If I chew on a bud, and blow into a device, marijuana will be present on my breath, but there's not way I would be experiencing any euphoric effects at all. Of if it had been a long time since I consumed marijuana, but the device detected a hint of marijuana on my breath, there's no way for it to determine the precise time that I had last consumed. There is a mad rush right now to get the first marijuana breathalyzer to market because law enforcement wants one that they can use to detect stoned drivers.
I read a very interesting article today on Buzz Feed during which a reporter named Amanda Chicago Lewis went to a marijuana expo and ran into the guys behind a company called Cannabix Technologies. Cannabix Technologies has claimed that they are on the cusp of being the first to the market with a marijuana breathalyzer that accurately captures whether or not someone is too stoned to be driving. After quite a bit of background about the marijuana breathalyzer concept in general, skeptical comments that were made about the Cannabix Technologies company, and specifically discussing the pros and cons of the Cannabix Technologies model of a marijuana breathalyzer, the reporter asks if she can try it. It had been 18 hours since she last consumed marijuana according to the article, so she was in no way impaired, but clearly had marijuana in her system.
The test registered as a negative. The reporter was impressed for a brief moment, until the truth about the effectiveness of the product came out. Per BuzzFeed:
For a moment, I was impressed.
But then Malhi said, "So this won't test positive, because we don't have the components for a positive result."
I was a little woozy, so it took a little while for the reality of what had happened to sink in.
"What do you mean, you don't have the components for a positive result?" I asked.
"We don't have the internal mechanism that would test for a positive result," Malhi said.
"So...what was that just testing?"
"Right now? It's just testing a blank test."
"So...even if I had smoked an hour ago, it wouldn't know."
"No. Not right now. Not the way it is right now," Malhi said.
"Yeah, the way it is, there's certain components we left at home," Mlait added.
"The components that actually test for THC...you left at home," I repeated.
"We're just not ready to do that demonstration yet, with the alpha version," Malhi said. "Until we have it right, we don't want to be demonstrating it. That's why we need to go to a beta version, before we hand it out for testing."
I really encourage you to read the entire article. It is probably the best article I've seen to date that debunks the marijuana breathalyzer dream product that law enforcement, many legislators, and marijuana opponents are hoping for. If Cannabix Technologies is the closest to launching a product, as the article suggests, I don't see why anyone would ever invest in such a product, regardless of who makes it. This idea is so far away from becoming reality, assuming it's even possible, that I think investors would be much better suited to just save their money, or invest it elsewhere in the cannabis industry.