By Timothy S. Donahue
The American vaping industry sits at a regulatory crossroads. On one side is the swelling market for illicit disposable vapes—largely foreign-made, flavored, and widely sold without U.S. Food and Drug Administration authorization. On the other is a shrinking group of U.S.-based companies trying to navigate the regulatory agency’s complex, expensive premarket tobacco product application (PMTA) process.
Glas Inc., a privately held vape manufacturer based in Southern California, is one of the few companies still standing in the latter camp. Founded in 2018 by former smoker Sean Greenbaum, Glas represents an increasingly rare breed: a U.S. vape manufacturer not affiliated with Big Tobacco, entirely independent, and fully committed to following the FDA’s regulatory rulebook—even at a high financial cost and years of commercial delay. “We’ve invested millions in this process because we believe compliance and safety matter,” says Greenbaum. “The problem is: we’ve done everything the FDA asked, and we’re still waiting.”
Since submitting its first PMTA in mid-2021, Glas has built what Greenbaum describes as the most comprehensive FDA submission of any flavored vaping product now awaiting authorization—a package that includes proprietary age-restriction technology, rigorous scientific studies, compelling smoking cessation data, and fully U.S.-based e-liquid manufacturing. While federal regulators have struggled to keep pace with PMTA reviews, Glas’s product remains stuck in regulatory limbo, its ability to compete hampered by the very rules it has spent years trying to follow.
A Deliberate Regulatory Bet
Glas’s PMTA process began long before its application landed at FDA headquarters. “We saw where the market was going early,” Greenbaum says. The company had already launched its first-generation product in 2019, gaining early traction in thousands of U.S. convenience stores, including major chains such as Circle K. However, as the FDA intensified its enforcement focus on youth vaping in 2020, Glas voluntarily withdrew its product from the market to concentrate entirely on developing its second-generation, fully compliant, age-restricted platform.
“We shifted everything toward building a product that would meet the public health standard under PMTA,” Greenbaum explains. “That meant investing in the science, the technology, and the manufacturing needed to address both moving adult smokers down the continuum of harm and youth access concerns head-on.”
In March 2021, Glas secured a rare meeting with the FDA—a significant accomplishment given that many companies have struggled to get agency access. “There were 29 FDA staff, on the call, including the former director of CTP’s Office of Science” Greenbaum recalls. The agency expressed early interest in Glas’s approach, calling it a “product with merit,” signaling that the Glas application would receive priority scientific review due to its technological innovation.
By July 2021, Glas submitted its initial PMTA for seven SKUs, a mix of flavored, menthol, and tobacco varieties at 5% nicotine strength, accompanied by its proprietary hardware device—an expanded application for lower nicotine versions followed in early 2022. By mid-2022, Glas’s submission had entered scientific review, and the FDA inspected the company’s U.S. manufacturing facility that fall.
However, after two years of review, the agency issued its first deficiency letter in April 2023. Glas responded within three months, providing additional data and clarifications. What happened next was highly unusual: a second deficiency letter, a rarity in PMTA proceedings. “We had never seen a second deficiency issued for anyone in this industry,” Greenbaum says. “It felt like a way for FDA to kick our can further down the road.”
The second letter requested a more extensive longitudinal switching study—essentially a long-term clinical trial comparing Glas’s products against existing FDA-authorized competitors. Glas delivered, submitting the full study results to the agency in April 2025. The data showed that Glas’s flavored products performed even better than authorized competitors at helping adult smokers quit combustible cigarettes. “Our Gold flavor reduced daily cigarette consumption by 73%,” Greenbaum says. “The data clearly shows that flavored vapor products can drive real-world public health outcomes.”
Ending Youth Access with Tech
At the heart of Glas’s PMTA—and central to its pitch to regulators—is the company’s proprietary age-restriction platform, which Greenbaum argues eliminates one of the FDA’s most persistent concerns: youth access. Unlike traditional vapes that can be purchased and immediately used, Glas devices arrive deactivated.
“The product won’t even turn on out of the box,” Greenbaum explains. “The customer must verify their identity using our smartphone app, which includes scanning government-issued ID, facial recognition, and a sophisticated liveness check.” Once verified, the device pairs with that user’s phone via Bluetooth. If the device is separated from the registered phone, it becomes inoperable. Random biometric check-ins during usage further ensure that the authorized user remains in control of the product.
This goes far beyond simple age verification at the point of sale. Glas’s technology addresses one of the most challenging problems in youth vaping: social sourcing, where legal buyers share products with underage peers. “We eliminate the social sale issue entirely,” Greenbaum says.
The company has submitted extensive data to back up its claims. Two independent age-gating studies showed 100% success at blocking underage users. Glas also hired cybersecurity experts to attempt to hack the system, but they were unsuccessful. “Nobody was able to break it,” Greenbaum says.
Each cartridge is also embedded with proprietary microchips to prevent counterfeiting, refilling, or tampering, a feature designed to combat the widespread problem of counterfeit pods in global markets. “We designed the technology to cover every potential avenue of youth access and counterfeiting that FDA has identified as concerns,” Greenbaum says.
Manufacturing at Home
Glas’s domestic manufacturing strategy is another way the company has distinguished itself from most of the industry. Although the device hardware is assembled overseas like nearly all vape hardware, the e-liquid—the core component of the product—is entirely produced and filled at Glas’s U.S. manufacturing facility using domestically sourced ingredients.
“All of the liquids are compounded, tested, and filled in our own U.S. facility,” Greenbaum says. “Every component has been tested for toxicology, emissions, coil performance, and chemical stability.” The facility employs more than 30 full-time staff members, maintains proprietary production equipment designed in-house, and operates entirely in accordance with ISO standards.
The company’s U.S. e-liquid filling operation also positions Glas advantageously amid growing international trade concerns. As federal policymakers increasingly scrutinize Chinese imports of nicotine products, Glas’s domestic liquid manufacturing allows it to argue that much of its product’s value chain is American-made—a distinction that may prove increasingly important as trade and tariff policies continue to evolve.
Despite its regulatory purism, Glas remains sidelined from the booming U.S. vaping market—now dominated by unauthorized disposable products overwhelmingly sourced from overseas. These illegal imports, which FDA has struggled to remove from shelves, continue to undermine both legitimate businesses and public confidence in vaping products. “The illicit market is creating the next public health crisis,” Greenbaum warns. “There’s no transparency, no safety standards, and no accountability for what’s inside many of these products.”
Ironically, Greenbaum argues that the FDA’s failure to authorize compliant, satisfying flavored products has allowed this black market to flourish. “Adults want flavors,” he says. “The absence of authorized flavors has created a vacuum that unregulated imports have filled.”
The consequences, Greenbaum believes, are twofold: the FDA’s own public health goals remain unmet, while companies like Glas—who followed the process in good faith—are left watching from the sidelines.
A Regulatory Crossroads
Glas is not alone in its frustration with the FDA’s slow-moving PMTA process. Across the nicotine industry, even some of the largest tobacco companies have faced multi-year reviews and shifting guidance as the agency struggles to balance public health interests against an increasingly chaotic marketplace. With fewer than 40 vaping products authorized as of mid-2025—all of them tobacco or menthol flavors in products produced by major tobacco companies—many PMTAs continue to be unresolved.
Still, Greenbaum remains cautiously optimistic that FDA will ultimately follow the science. “When we filed, we were the first to propose this kind of comprehensive age-restriction technology,” he says. “Since then, FDA itself has started to incorporate language into denial orders referencing the absence of effective age-gating. It’s clear they recognize its value.”
Greenbaum views FDA’s authorization of menthol-flavored vapor products in 2024 as another encouraging sign. “It’s been incremental: first tobacco, now menthol. The next logical step is properly regulated flavors supported by strong age-restriction controls.”
If authorized, Glas is fully prepared to scale up quickly. “We could have the product on shelves within 90 days,” Greenbaum says. Distribution partnerships are already in place, and manufacturing is ready to operate at commercial volumes. “We’re fully built, staffed, and positioned for rapid growth.”
The stakes are high—not only for Glas but for the entire structure of America’s nicotine regulatory framework. Greenbaum believes FDA now has a unique opportunity to correct course and reclaim control over the marketplace it was tasked with overseeing. “One FDA ruling could save adult smokers, protect kids, and finally crush the black market,” he says. “We’ve done the work. We’ve invested everything to do this the right way. All we’re asking is for FDA to finally act.”
