The woman behind the curtain is busy today. She has too many orders to fill. Bottles of chemicals surround her as she leans over a small table and mixes a little from one and then another to create a "house blend" recipe while customers linger in the front room of her and her husband's vape shop in Arlington.

A couple of young guys wearing black concert T-shirts and blue jeans, another with a shirt promoting American Eagle, stand near an island with hundreds of bottles of flavor samples. Drawing clouds of thick, smoky vapor from hand-held devices made of polished chrome, glass and LED lights, they look as if they're puffing Jedi light sabers instead of personal vaporizers, a fancified kind of electronic cigarette that uses nicotine-laced "e-liquid" in place of burning tobacco.

"Can you blow smoke rings with it?" asks one, exhaling a blue-tinted cloud.

"I can do a tornado with it before I can do rings," says John Smith, the shop owner. He takes a deep drag from his titanium-plated personal vaporizer, or "vape pen," leans over a black folder listing his shop's more than 600 flavors and exhales a cloud that spins for a second or two before disappearing.

Mods, gearhead, grindpunks, dual coils for some, saturating for others — their lingo sounds like something you'd hear at a motorcycle shop with Ozzy Osbourne's "Shot in the Dark" playing in the background.

Behind the curtain, Melanie Smith doesn't wear a lab coat or protective covering over her clothes, shoes or blonde hair. But she does wear rubber gloves as she uses syringes to create popular flavors like "Stormy Weather," "Suicidal Zombie" and "Grandma's Backyard."

She's known as a "mixologist," and she's one of more than five dozen working in vape shops across North Texas. Her "lab" is in the backroom of Rock 'n' Roll Vapes, a shop she and her husband opened about a year ago in Arlington. It's one of the many e-cigarette shops that seemingly appeared overnight. Good Vapes in Dallas, Vape Lounge in Carrollton and Vape 'N' Vapors in Denton have sprouted up since 2009, offering customized e-liquid, or "house blend" or "house juice," with monikers like "Andy's Mint," "Alice Cooper" and "Midnight."

With no oversight from the federal government or local health departments, it's like the Wild West days in the vaping business, with more and more backroom mixers brewing products that satisfied customers swear is a safe, effective way to kick tobacco. Scientists and regulators, however, have not yet weighed in on vaping's long-term safety, but that's coming, and the small business owners are worried.

Each shop has a different "trade secret formula" made from a mix of basic ingredients spiced with flavorings and scents. There are no directions to follow; the most popular recipes are created through trial and error.

"It's simple math," Smith says. "It was literally just figuring it out by combining mixes and vaping it." He takes several long draws from his vaporizer. "Our most popular flavor — Suicidal Zombie — takes a lot of different flavoring."

Located just off Green Oaks Boulevard, Rock 'n' Roll Vapes offers a wide selection of personal vaporizers, vape kits and vaping e-liquid, all Rock 'n' Roll themed with names like "Blacktooth," "Subway to Venus" and "The Red Door," and all mixed in the backroom of the shop from a blend of chemicals ordered online.

Mixologists start with food additives — propylene glycol or vegetable glycerin, which create a smoke-like cloud of vapor when heated by a battery-powered element in a vaping pen. Added to the PG or VG are nicotine and a range of scents and flavorings to create a smoking substitute that fans say creates the sensation of smoking without the nasty, carcinogenic byproducts of burning tobacco.

Still, the ingredients mixologists use were not made to be vaporized. Too much nicotine is toxic, and the wrong amount of the food additives can make a user sick. It takes concentration to mix these ingredients correctly, and that can be hard to find when some vape shop owners' mixing stations are in the same area as the office or bathroom, or on a workbench filled with broken vape pens and mechanical parts.

Like many other shop owners, Smith quit smoking because of vaping, soon realized the benefits it could offer smokers, and saw the growing demand for vape shops in the area. So he traded his livelihood as an electrician and opened Rock 'n' Roll Vapes, about the same time Frisco was ordering e-cigarette users to the smoking section and Watauga was banning the sale of e-cigarettes. (E-cigarettes are designed to look vaguely like cigarettes; they're most often disposable. Personal vaporizers range from pen-sized to behemoths with large, rechargeable battery packs and refillable tanks to hold "juice." They also come with an array of colors, designs and accessories to dress them up.)

"The biggest mistake that ever happened was calling them electronic cigarettes," Smith says.

Vaporizers have become something more than just a product for people to use to quit smoking. People who've never smoked a cigarette are vaping, and they're gathering at vaping conventions, in lounge areas of vape shops and at local parks. It's become a social experience.

Last year, "vaping," which includes e-cigarettes, was a $1.5 billion industry, according to Bloomberg Industries analyst Kenneth Shae. Cigarette makers like Reynolds American marketed e-cigarette products as safer alternatives to cigarettes, a move that some people see as the tobacco industry trying to recover lost sales.

But now the FDA wants to bring law to the Wild West with regulations that business people like Smith say threaten to destroy everything they've built, killing a small industry in its cradle and, some would argue, turning people back to smoking.

In the FDA's proposal, e-cigarette products formulated after 2007 must get FDA approval to be sold, which means vape shops like Rock 'n' Roll Vapes will have to hire experts to determine the health impact of the device, which the Consumers Advocates for Smoke-free Alternatives Association (CASAA) estimates will cost between $3 and $4 million and take 5,000 hours for each application. They may even have to register each ingredient used in their "house blend," which for someone like Smith could cost a few more million.

"I want to make a living," Smith says. "I want to provide for my family, not pay a ton of money to government regulations" that many people feel are designed to push the small business owner out of the e-cigarette industry.

John Smith had been a smoker for more than 20 years. He picked it up when young, about the time he started playing in local bands. Over the years, he tried a number of ways to quit, including an electronic cigarette he purchased at a convenience store.

The first version looked like a plastic cigarette when it hit the market in early 2006. A Chinese pharmacist, Hon Lik, 52, is credited for creating it. He reportedly invented the smoking cessation device after his father died of lung cancer. It was a simple setup: Suck on it like a cigarette, and a battery in a chamber powers a heating element that vaporizes a preloaded mix of nicotine-laced liquid.

Since the devices resembled cigarettes and provided a similar effect, the World Health Organization proclaimed that e-cigarettes weren't a safe alternative to cigarettes. In 2009, the FDA requested The Center for Drug Evaluation and Research to conduct a study on two brands of e-cigarettes, Njoy and Smoking Everywhere Electronic Cigarette. Researchers found both brands contained nicotine, carcinogenic nitrosamines, and other tobacco impurities at low levels. They also detected diethylene glycol, a toxic chemical found in antifreeze.

"The FDA is concerned about the safety of these products and how they are marketed to the public," said Margaret Hamburg, the FDA commissioner of food and drugs, in a 2009 press release. "[E-cigarettes] have not been submitted to the FDA for evaluation or approval. At this time the agency has no way of knowing, except for the limited testing it has performed, the levels of nicotine or the amounts or kinds of other chemicals that the various brands of these products deliver to the user."

The FDA directed the U.S. Customs and Border Protection to halt entry of e-cigarettes into the United States but e-cigarette domestic manufacturers were already popping up all over America. People liked them, and soon e-liquid recipes were appearing online alongside "how to mix e-liquid" videos, which generated thousands of likes on YouTube. Vape shops like DFW Vapor began offering a variety of e-cigarettes, vape kits that included personal vaporizers and premade vape flavors to customers who wanted a more satisfying taste.

The e-cigarette that Smith first tried tasted like shit, he says, so he went back to smoking cigarettes. In 2012, his cardiologist recommended that he try a type of e-cigarette unlike those sold at gas stations. It was called a personal vaporizer, or "vape pen," and offered flavors like strawberry, blueberry and watermelon.

Sleek in appearance, these new e-cigarettes, or "alternative e-cigarettes," allow users to hit a variety of nicotine substances. Producing little odor, they've become a common sight on college campuses, at house parties and in subway stations. In fact, the number of people who've tried an e-cigarette has risen to 15 percent in the United States, according to a recent study, and use among middle- and high school students doubled from 2011 to 2012, with more than 10 percent of high schoolers trying them.

Smith went to Vixen Vapors in Pantego and told the store clerk that he smoked a pack and a half a day. He was hooked up with tobacco-flavored e-juice spiked with 24 milligrams of nicotine per milliliter liquid. He bought a titanium-colored vape pen, walked out of the shop, loaded it and inhaled.

"It's the feeling of drawing something into your lungs," Smith says. "We call it a 'throat hit.' The feeling you get in the back of your throat is for me the biggest thing."

He quit smoking cigarettes that day and slowly weaned himself off the nicotine additive in his e-juice, lowering the amount in increments. Today, he uses 2 milligrams per milliliter.

A few months later his coworkers, family and friends began asking questions about the titanium-colored pen. He told them about his vaping experience, and his wife, Melanie, went to Vixen Vapors and bought herself a vape pen with peanut butter flavoring. She also quit smoking. His father and bandmate soon followed.

But Smith wasn't completely satisfied with premixed flavors. A 30 milliliter bottle of e-liquid costs anywhere between $15 to $25, and he began researching the ingredients and realized that he could make his own blend. It took him 48 hours to learn how to create a "house blend." It took only two attempts to create "Mango Melon," which he made for his wife. Next was "Blueberry Hill," a blueberry lemon cheesecake flavor that took several attempts to perfect.

"After a week or so of mixing, knowing what amounts of different flavorings to use to achieve what I was aiming for got easier," Smith says.

Mixologists tinker with various candy and perfume flavorings to create popular combinations like "Almond Amaretto," "Brandy" and "Cafe Rum." Candy flavoring is easily accessible online, but candy flavoring companies like Flavor West, a popular brand used in e-juices, are distancing themselves from vape shops.

"The flavoring is strictly for candy, not vaping juice," says Jason Sterns, a spokesperson for Flavor West. "But we don't ask customers what they're using it for."

Fragrances from Perfume Apprentice are another item mixologists favor in house blends, but the company recently posted a disclaimer on its website: "These items are intended for student perfumers and flavorists. Please note that very little testing on inhalation of these materials has been done, and so we can not recommend them for this use."

Smith ordered flavored ingredients from both companies and began combining and tasting various flavors in his home. He slowly perfected his Rock 'n' Roll recipes. He'd fill up a backpack with his customized e-juice and sell it at music festivals and local concerts. He sold it to his coworkers and their friends and family, all smokers who quit smoking because of vaping.

"So what I'm seeing from a lot of people are success stories with e-cigarettes and vaping," Smith says. "Me, I can run three miles now, and I'm not out of breath. It's been a miracle for me."

Seven months later, Smith created an online store to sell his house blend and eventually opened his shop in Arlington. "Rock 'n' Roll Vapes" is what his wife wanted to name it. "Rock music has always been a huge part of who both of us are," he says.

Located in a strip mall, Rock 'n' Roll Vapes looks more like a tattoo shop than a head shop. Heavy metal hits from the '80s and '90s echo throughout, and music memorabilia decorate the walls. A couple of tables with records covering the stools offer customers a place to wait as their e-liquid is being mixed. A small island with samples of the 620 customized flavors offered always has someone vaping the different preloaded canisters, searching for that perfect flavor.

On average customers order between 8 and 12 milligrams of nicotine, which is the recommended dosage for a person who smokes 10 cigarettes a day, in their customized e-juice. Some shops will offer as high as 36 milligrams, but 24 milligrams is the highest dosage offered at Smith's shop.

"A vast majority of my customers are vaping instead of smoking cigarettes," he says, "and they just want to replace that flavor, so they're fine with the premixed canisters. Then you have a different group that like the mods [personal vaporizers that owners tinker with to boost output], that like the bigger hit, that are really into the flavors and the technical side of things. It's like Doctor Who fans or Trekkies. It's a subculture."

Besides offering his own house blend, Smith also stocks premium quality e-juice like Suicide Bunny. It's made in Dallas, and costs more than the other products, as much as $25 for a 30 milliliter bottle compared with $12 or $15 for house blend. Suicide Bunny can be found in more than 600 vape shops across the U.S., Malaysia and France. This premium e-liquid is the creation of a woman called Pip "The Bunny" Gresham, not because she posed for Playboy, but because she's like the Energizer Bunny, her husband says, always on the "go, go, go."

Until recently, it was unlawful in Texas for someone to bake cupcakes in his home and sell them, because of health concerns about what was in them. But vape shops are operating with no local or state regulations. A health inspector doesn't visit the shops and make sure the ingredients are stored properly or mixed correctly. Richardson requires a special permit to open a vape shop, a zoning regulation that is similar to what a payday lender must obtain to open his business.

"We had eight shops open in an eight- to 10-week period," says Michael Spicer, director of development services. "We've never experienced anything that abrupt with businesses before. We wanted a little more scrutiny."

Vape shops that want to open in Richardson are required to apply for the special permit, then a city plan commission reviews the request and City Council votes on it after a public hearing. Since the adoption of the ordinance in November 2013, they've had one application, he says, and the request was denied.

"It wasn't a suitable location," he says. "It was up along George Bush Turnpike, an entry point to our community."

Pip "The Bunny" Gresham is a perfectionist when it comes to her products. She once spent nine hours sitting in her lab trying to create another flavor to add to her line. "I'm still not there," she says, setting down her syringes. She'll try again the next night.

It took her three months mixing e-liquid ingredients in her kitchen to perfect a flavor that her husband, Scott, would enjoy. He'd been trying to quit smoking, but the blends offered at local vape shops weren't very good. "There's a difference between ingredients and the quality of ingredients and the substance of the juice," Pip says. As some people turned to message boards to complain about side effects like dry mouth, itchy throat, tight lungs and funky-smelling urine, she decided she wanted to create a quality product, not for profit but for her and her husband's health.

"For a shop, it's always about the bottom line, trying to make a profit," she says, which often leads to using cheaper ingredients or cutting corners when it comes to safety.

Pip had been to some of the local shops and wasn't impressed with the lab setups behind the curtains. Besides not having a clean room for mixing, mixologists also didn't wear protective clothing or properly store the ingredients.

"For me, I needed to know the quality of ingredients that I'd be giving to my husband to put in his body," she says. "It was very important to me that I knew what was in this stuff."

Pip first researched e-liquid online and spoke with the owner of a leading juice company. "After that it was like a ball of yarn," she says. She reached out to PG/VG manufacturers and flavoring manufacturers to talk at length about their products. She then began ordering what she considered quality ingredients online and creating alternative flavors by combining candy flavoring with higher and lower ratios of the e-juice's base ingredients. She went through more than 100 different recipes before she perfected a flavor she and her husband would enjoy.

"Mother's Milk" is what Pip called the perfect flavoring. "Mother's milk is the source of life," she says. "I thought it was appropriate." She started bringing it with her to vaping conventions and events, and people would ask her what flavor she was vaping. She'd let them try it and soon she had people coming to her house and picking up small bottles of Mother's Milk from her front porch.

Pip knew she couldn't continue allowing people to come to her house to pick up her premium e-liquid. She wasn't a drug dealer. But people loved her product. She asked her husband if he wanted to start selling the stuff. Scott agreed, and Pip contacted a Canadian artist who drew her several designs.

It took her nine months to perfect nine recipes, and her first order was to an online vape store that requested 540 bottles. Everyone was talking about the new e-liquid in town. Soon a representative from Wolfpack Distribution in Dallas contacted her with an offer to become her distributor.

Today, Suicide Bunny has a 2,200-square-foot facility in Dallas. The customized e-liquid is mixed in a clean room and stored in a separate sealed room. It's not a practice mandated by the FDA or the local health department, but Pip took it upon herself to create a clean environment.

"I've seen stuff that would make your skin crawl," she says. "I've seen a shop where the mixing material was actually located in the bathroom. When I see stuff like that, there needs to be some regulation because that can't be happening."

Pip followed one simple motto when designing her clean room: "If I'm going to put this in my body, this is how I would want it made."

Suicide Bunny now can be found in about any shop in North Texas. Offered in small vials with images of tattooed girls on the side, the product just looks hip, and Pip has been promoting it at conventions and expos like the World Vapor Expo in Miami. It's becoming a popular premium brand, with more than 11,000 likes on her Suicide Bunny Facebook page alone.

But now the FDA's proposed regulations threaten her growth, especially since the agency wants mixologists to register each individual flavoring ingredient. "I'm 100 percent for some kind of regulation," Pip says, but she worries that registering every ingredient used in her nine flavors would be costly. "It would be a pretty big chunk of change for us to do it, and it's my understanding that once you pay the fee, the FDA still has the power to deny you."

Ironically, the same big tobacco industry that long denied its product was a killer and ruthlessly fought any attempt at regulation is standing behind the FDA's proposed rules. Industry leaders like Lorillard, makers of Blue e-cigarette, and Reynolds tobacco, maker of Vuse e-cigarette, can afford the fees and could gain by thinning the playing field of small vape shops and juice makers.

Along with requirements that liquid makers lists ingredients, the FDA's proposals would impose a costly registration and approval process that would effectively eliminate refillable devices, which is a bad thing, says Dr. Carl V. Phillips, a CASAA scientific director.

"FDA has cherry picked the available evidence," he wrote on the CASAA blog, "blindly accepting any assertion that favors aggressive regulation and ignoring the overwhelming evidence about the harms that these regulations would cause."

The FDA regulations would classify e-liquid and "house blends" and e-cigarettes and personal vaporizers (as well as any accessory or part like the battery) as a tobacco product. E-liquid makers would have to submit an application for each flavor, listing the ingredients separately. If vape shops are offering 20 different strengths of nicotine, they would need to submit 20 different applications.

"We would end up buying premixed flavorless stuff that was FDA approved," says John Smith of Rock 'n' Roll Vapes, "and we would sell liquid candy or 'flavor shots' separate and say it wasn't intended for vaping purposes."

When the FDA released their proposed regulations in April 2014, the public had only 75 days to respond, but consumer advocacy groups like CASAA requested an additional 180 days to reply to the 99 requests for information about "tobacco harm reduction" products regulators at the FDA had posed.

CASAA formed in 2009 to raise awareness and protect consumers' rights to access smoking alternatives. Today, 17,700 people have registered as members. Like many other vaping shop owners in North Texas, Pip and Scott Gresham of Suicide Bunny and Smith of Rock 'n' Roll Vapes are supporters of the various vapor advocacy groups, banding together in response to the FDA's regulatory stance. They believe organizations like CASAA are protecting their rights as a consumer, a manufacturer and a retailer of e-liquid and alternative e-cigarette products.

CASAA leadership spent weeks analyzing the FDA's regulatory impact analysis, the Tobacco Control Act and data about the FDA's operations to assess real-world implications of the proposed regulations. They realized this was more than just regulating a new industry. This was a battle for the heart of the e-cigarette movement — the smokers who were using them to quit.

"Higher quality hardware and appealing flavors are important for smoking cessation," Phillips says. "Many former smokers report that they were always tempted to go back to smoking while using the smaller devices with imitation tobacco flavorings, but they quit smoking for good when they found better hardware and flavors that no longer reminded them of smoking."

"We believe that FDA has used completely inappropriate estimates for the paperwork costs of this regulation," a CASAA statement reads. "Basically FDA is either wrong about their estimates or are explicitly saying that all of the other products will be driven off the market."

In an interview with the Los Angeles Times, Tom Frieden, the director of the Centers for Disease Control and Prevention, claimed e-cigarettes were just as dangerous as regular cigarettes. He also warned personal vaporizers could be re-glamorizing smoking. "I see the [electronic cigarette] industry getting another generation of our kids addicted," Frieden said. "To me, as a physician, when 1.78 million of our high school kids have tried an e-cigarette and a lot of them are using them regularly ... that's like watching someone harm hundreds of thousands of children."

CASAA disputes these claims. E-cigarettes, advocates say, aren't known to cause people to start smoking cigarettes. Some people smoke personal vaporizers without adding nicotine to their e-liquid. In a letter to a city council hearing on including e-cigarettes in the smoking ban ordinance in New York City, former U.S. Surgeon General Dr. Richard H. Carmona wrote, "Each year only 6 percent of smokers succeed in quitting, and new smokers replace those who successfully quit. The history and data suggest that we need more viable alternatives in this fight against tobacco. I believe that one such alternative is the electronic cigarette. Despite their unfortunate name, electronic cigarettes are not actually cigarettes. They contain no tobacco but rather deliver nicotine without all of the toxic, carcinogenic and other disease-causing products of tobacco combustion."

The former surgeon general, however, also sits on the board of Njoy, the leading independent electronic cigarette company.

Advocacy groups like the Vaping Militia out of Minnesota have set up websites with numerous studies available for the public to read, in hopes of educating and slowing the regulation of e-cigarettes in places like Frisco where vaping is regulated like cigarettes.

"There was a strong push from businesses in the community," says Scott Johnson, city council member of Frisco, "and with continued warnings from the Heart Association, banning them in public places was needed."

But most of these studies are short term, and scientists acknowledge that solid data on the risk of vaping is poor. Too few longitudinal studies have been conducted to understand the long-term effects of inhaling products made with candy and perfume flavoring. The FDA is accepting additional research and comments on proposed regulations until July 9, but CASAA is asking members to wait until just before deadline to send their responses.

Gary Wood, an education coordinator for Vapors Advocacy Group in Texas, reminds vape shop owners that regulations aren't the law of the land yet. It could take up to two years for the regulations to go into effect. He says self-regulating e-liquid by not selling to minors is just the first step and warns that people mixing house blends need to make sure they are concocted in a clean environment.

"What we do have in the industry is a lot of self regulation if the e-liquid is being made properly," Wood says. "Are they being made in an American E-Liquid Manufacturing Standards Association-certified lab? Are they made with pharmaceutical-grade FDA-approved nicotine if they're using nicotine? Is it truly quality ingredient for the propylene glycol and vegetable glycerin? Those are the kinds of things people should be looking at."

The American E-Liquid Manufacturing Standards Association (AEMSA) acknowledges that liquid nicotine is an ingredient of concern and requires professional handling and distribution. So it set forth a list of standards that demand high quality and accuracy in content. It promotes self-regulation of e-liquid manufacturing, providing consumers with "a greater confidence in our members' products."

Shops mixing products behind their counter is a bad thing, says Brett Coppolo, a charter member of AEMSA. "If the FDA has anything to say about it, they won't be doing it anymore."

But most vape shops offering house blends in North Texas aren't using AEMSA-certified labs. They section off the backs of their shops with a curtain. This fact, some in the industry believe, just adds to the fear causing a "knee-jerk" reaction from city councils across Texas, sending personal vaporizer users back to the very place they've been trying to escape: the smoking section.