This post is part of our High-tech High series, which explores weed innovations, and our cultural relationship with cannabis, as legalization in several U.S. states, Canada, and Uruguay moves the market further out of the shadows.

It's not easy being green — especially at CES, the world's largest consumer electronics convention. Marijuana tech companies are grumbling about how difficult it is to participate in CES 2019 because organizers will not allow them to exhibit.

"We’re not allowed on the showroom floor, and it’s apparently because [organizers] say they haven’t created a category for cannabis vaporizers yet," says Jeff Brown, vice president of public policy and communications at PAX Labs, an electronic vaporizer company.

"Apparently they’re not comfortable with cannabis. It’s odd and mildly frustrating," he adds. "Nevada is a medical and recreational [consumption] legal state, and there’s certainly no shortage of alcohol being served at CES. There are concessions everywhere. To draw the line at a technology company demoing cannabis is odd and frustrating."

"Apparently they’re not comfortable with cannabis. It’s odd and mildly frustrating."

For a company like PAX Labs, the consequence of not being able to participate in a convention like CES can be devastating. The Consumer Technology Association (CTA), the trade organization that hosts CES, estimates 180,000 people will attend the conference this year with more than 4,500 exhibiting companies and more than 6,500 media workers.

For a startup like Pax Labs, the type of exposure and backroom deals that can be made at a conference like CES can catapult a company from tiny startup to full-fledged industry leader.

Mashable spoke to the CTA about its decision to prohibit marijuana technology companies from exhibiting at the conference. In an emailed statement, the CTA said, "There are no cannabis or e-cigarette products on the exhibit floor at CES, as the show does not have a category pertaining to that market. As the industry and regulations evolve, we continue to assess all categories."

Of course, not everyone is happy with the association's logic. "It feels counterintuitive for a platform centered around innovation and progression to have such a conservative viewpoint on something that millions of people use and find significant benefit from," says founder of portable vaporizer company Puffco, Roger Volodarsky.

Other marijuana tech company executives agree. "We think the biggest challenge facing the cannabis industry right now is that millions of people are trying cannabis for the first time, and millions of people are coming back after a long hiatus, and they don’t know what to expect," says Brown. "Technology can help solve that problem, but CES won’t let us do that."

Marijuana isn't exactly a hidden phenomenon in Las Vegas, either. Attendees at CES regularly get whiffs of marijuana outside of the larger hotels on the Las Vegas Strip. The Nevada Department of Taxation estimates more than $340 million in recreational marijuana sales occurred from July 2017 to April 2018. Estimates from Cowen investment bank suggest the legal weed industry could generate $75 billion in the U.S. by 2030.

But for now, marijuana companies are being forced to exhibit off-site at CES, against the will of the organizers. "This movement has too much momentum to be stopped now," says Volodarsky. "CES has the opportunity to lead the stage for innovation in our field. Not doing so just gives the opportunity to someone else to capitalize on all the interest in the cannabis space."

And for savvy attendees, there are plenty of marijuana companies demonstrating tech products during CES — albeit outside of the convention center at unofficial events. Maybe next year they won’t be forced to puff in the shadows.