Vinh Nguyen gives his customers at Vapor Bombz every warning there is about electronic cigarettes and the liquid nicotine that fuels them.

Show me ID. Mind the labels and the dosage. Got kids? Try a resistant cap, or the vial in shrink-wrapped plastic. Keep vials out of reach, out of sight. But once money changes hands and customers leave his shop, however, it’s up to them to be responsible with what is, after all, a toxic product.

“We tell them this stuff is poisonous,” says Nguyen, 30, who co-owns the shop with his brother Steve. “We do everything we can to protect the consumer, but at the end of the day, you leave a loaded gun on the floor, and your child gets hold of it, it’s not gonna be the gunmaker’s responsibility.”

The vaping industry, which has grown quickly in Southern California the past few years, went into a defensive crouch Monday, defending itself against a New York Times story that highlighted a trend of rising calls to poison-control centers linked to e-liquids, the term used for the thick substance that’s combusted inside electronic cigarettes. Across the nation, the number of such calls rose threefold from 2012 to 2013, to 1,351.

Many have been sickened, but the only recent death, according to the story, appears to have come in 2011, when a man injected himself with nicotine.

E-cigarettes and liquid, also called “juice,” have been hailed by proponents as a way for addicted smokers to get their nicotine fix without sucking in the thousands of carcinogens found in traditional cigarettes. Some long-term smokers swear by them, and regularly flock to local vape shops to stock up on juices to fill up the tanks on their devices.

The liquid normally is a mixture of water, flavoring and propylene glycol, a compound that allows the juice to atomize at a relatively low temperature. When it burns, it delivers a hit of nicotine through a mouthpiece. If a vaper fills up a 4.5-milliliter tank with juice that’s 1.8 percent nicotine, and makes it last all day, he’ll inhale roughly 80 milligrams of nicotine, or the same amount that’s in about 10 cigarettes.

It would take an awful lot of puffing to overdose on nicotine that way. Science is unclear on the long-term effects of nicotine when it’s not delivered by cigarettes. But another way it can be harmful is direct contact.

In its purest form, nicotine, which is extracted from the tobacco plant, can be toxic to the touch. But the product juice-makers buy, often in jugs or barrels, already is diluted to about 10 percent. If enough gets absorbed through the skin, from a broken vial, for instance, it could make a person nauseated to the point of vomiting.

The real danger, though – and the thrust of the New York Times story – is the possibility that children could happen upon a vial of juice and ingest it.

“These fluids come in flavors that are attractive for kids,” said Dr. Helene Calvet, deputy county health officer for Orange County’s Health Care Agency. “If a kid gets hold of this and sucks down even a small amount, it could be pretty dangerous.”

Nicotine would be potentially fatal for an adult who ingests 0.5 to 1.0 milligrams per kilogram of body weight. But for children, that threshold could be as low as 0.1 mg per kilo, says Dr. Chesda Eng, a smoking-cessation specialist with St. Joseph Heritage Medical Group in Garden Grove. If a child ingests “maybe a teaspoon, that can be lethal.”

Some e-cig proponents took serious issue with The Times’ reporting: nicotine levels in most juicers “range between 1.8 percent (18 mg per ml) and 2.4 percent, concentrations that can cause sickness, but rarely death, in children. But higher concentrations, like 10 percent or even 7.2 percent, are widely available on the Internet.”

Vapor Bombz and many other stores carry vials with concentrations to 1.8 percent, but no higher. “We feel that it is unnecessary to be that high in the first place,” said Nguyen, who is a co-partner of an Anaheim juice-maker, Epic Juice. A vial that’s 2.4 percent would mostly be used by a long-term smoker trying to maintain his fix until he can reduce the dosage.

The New York Times noted that Minnesota’s poison-control center received 74 calls in 2013 related to poisoning cases from e-cigs or nicotine. Of those, 29 were children 2 and under. But an e-cigarette advocacy group called the Consumer Advocates for Smoke-free Alternatives Association noted that same center received 35 calls about nicotine-replacement therapy products, as well as 2,300 calls for household cleaners and 3,100 calls related to personal-care products.

“E-cigarettes have proven to be a way of quitting for lots and lots of people who tried every other way and failed at them, so that alone means that they are saving peoples’ lives,” said Carl V. Phillips, a tobacco researcher and the group’s scientific director, based in Nashua, N.H. “A lot of them have the potential to quit smoking next week if they try it, and they won’t if they’re being convinced that they’re just as bad as smoking, or if they’re convinced that it’s a dire hazard to their children if they even have them around.”

E-cigarette users, manufacturers and local governments forced to come up with patchwork solutions are all hoping the Food and Drug Administration will issue some kind of guidance on e-cigarettes and liquids soon. The FDA has the authority to regulate the devices and juices, along with other tobacco products, but the agency is waiting on the Office of Budget and Management to review the “deeming rule” before it acts.

“We’re not seeing an epidemic of kids getting overdosed with nicotine,” Eng said. “With that said, the popularity of e-cigarettes is increasing, and I can see this becoming a problem if it’s not dealt with right now. And I think the FDA needs to step in.”

Contact the writer: lhall@ocregister.com or 714-796-2221