With the notable exception of, well, any episode of Mad Men, a prominent Hollywood actress smoking on television, or in public for that matter, is a rarity. Particularly during a live network broadcast awards show.

Yet there was Julia Louis Dreyfus, blithely puffing away during last week’s Golden Globes ceremony (pictured). Her sunglasses and steely demeanour implied she was gently mocking the late Elizabeth Taylor. More notable was the fact  Dreyfus was not sucking on an old-fashioned dart, but an electronic device known as an e-cigarette.

E-cigarettes dispense nicotine without combusting tobacco; their key selling point is that they produce a vapour, not smoke. The devices are battery powered and work by heating nicotine, propylene glycol and glycerine into a vapor, which is then inhaled.

Hence the former Seinfeld star was not smoking, she was vaping.

While e-cigarettes remain something of a niche product in Australia, they are swiftly becoming mainstream here in the United States. The rapid growth is outpacing legal and social guidelines regarding their use.

With societal and legal etiquette not yet established and the product itself increasingly popular, e-cigarettes have become the centre of a public health debate that is swiftly turning aggressive. As with most matters of ethics and commerce in the US, several groups with vested interests are attempting to stake their claim on the issue.

As the US has shivered through a frigid winter, vaping has been a highly visible fixture in cars, living rooms, bars, restaurants, concert venues and almost any public building. A mostly unregulated cottage industry of manufacturers and distributors is seeking to exploit its growth.

Henleys, the first e-cigarette bar — a self-proclaimed vaporium, if you will — has opened in New York’s Soho neighbourhood. The company is planning three more for the first half of this year. Celebrities such as John Mayer, Katy Perry, Courtney Love, Bruno Mars and Leonardo DiCaprio are out and proud vapists. Photos of Michelle Rodriguez vaping at a basketball game went viral.

Industry estimates put the value of the American tobacco market at about $90 billion a year. Although a fraction of that, the $2 billion of annual revenue generated by e-cigarettes is remarkable considering the brief time they have been on the market.

There are now more than 200 companies manufacturing and marketing e-cigarettes. The two most popular brands are NJOY and Blu, the latter of which is owned by tobacco conglomerate Lorillard (you may remember the company from Troy McClure-helmed skits in The Simpsons as Laramie Cigarettes). Camel Cigarettes maker Reynolds American and Marlboro owner Altria Group are also taking their e-cigarette brands national later this year.

The US Food and Drug Administration is expected to recommend the product is reined in by some regulation, however tepid. Several sources suggest a decision is pending (it was originally due last October, but was held up in the government shutdown).

Lorillard spent $30 million last year advertising its e-cigarettes on US television. NJOY will outlay the same amount in 2014. In 2012, the industry’s total spend was just $1.1 million.

Actor Stephen Dorff is currently featured in a series of television commercials promoting Blu. The ad’s theme is “take back your freedom”. It features the actor vaping in an airport, on a train and at a concert. And TV is far from the only medium: the group has also published full-page ads in The New York Times, in various magazines and on billboards atop of taxis.

“We’re trying to do something very challenging: change a habit that is not only entrenched but one people are willing to take to their grave.”

Similar to Australia, tobacco companies have been banned from advertising cigarettes on US television since 1971. Like many traditional anti-smoking initiatives, e-cigarettes currently skirt this law. This alone has health groups concerned.

This week marks the 50th anniversary of the US surgeon general’s report into the hazards of smoking, published in 1964. Back then, 43% of Americans smoked; as of 2012, that figure had dropped to about 18%.

According to The Los Angeles Times, the FDA’s Center for Tobacco Products is collecting reports of adverse effects from e-cigarettes. Complaints include claims of eye irritation, headaches and coughing.

Three states — New Jersey, Utah and North Dakota — now ban e-cigarettes in smoke-free venues. A cluster of cities, including Boston, Seattle and Savannah do the same. Last September, 40 states came together and exhorted the FDA to regulate e-cigarette marketing.

Critics suggest rather than helping smokers quit, the product may be a sort of gateway drug teens will use on the way to taking up regular ciggies. With smokers now social outcasts, vaping, the Office on Smoking and Health at the Centers for Disease Control and Prevention says, could make “smoking” cool again.

Some 1.78 million teens and children are said to have tried vaping in the US last year. So concerned are educators in Miami, school boards are working on legislation to formally ban them from high schools. Extraordinarily, there is no age limit for buying the products.

On a recent Friday evening at the Mickey Byrnes Irish Pub in Hollywood, Florida, three locals sat at the bar vaping. To the outsider, it felt like something of a throwback. Aside from the odd double take, nobody seemed to mind. In fact, others subsequently fired up in other parts of the room. Bar staff did not bother them.

The pub’s co-owner Mark Rowe was pragmatic when asked by Crikey if he was concerned by the trend. “I don’t mind if people smoke them now, as I don’t have any evidence that they are harmful,” he said. “They are very popular. I’d like to know more before I give an opinion on whether they should be banned. [But] I’m sceptical about them as of now.”

A cluster of noted pro-vaping advocates, such as Times columnist Joe Nocera, say too many wowsers are diluting a key point: why should a product that will potentially help a lot of people quit smoking, and potentially increase their lifespan, be so demonised? Nocera quoted an industry advocate who noted anti-tobacco advocates had spent so many years arguing from “a total abstinence framework” that they hadn’t been able to move from that position. It may inadvertently drive popularity of e-cigarettes.

The industry also argues products such as nicotine gum and patches have done the same job with little public disquiet for many years.

In Australia, the laws are a little less fluid. Firstly, according to the Therapeutic Goods Administration, it is illegal to sell any e-cigarette that proclaims to bestow any therapeutic benefit (i.e. helping you quit smoking regular cigarettes). So that rules out the top-selling US brands. But if no benefit is claimed, at this stage, the product is legal. The department does offer a broad observation, however: “The Australian Government is concerned about the use of electronic cigarettes in Australia.”

Somewhat mischievously, daily deals site Groupon has been marketing them locally with a caveat that they cannot be ordered in Queensland, South Australia and Western Australia.

Back in the US, Craig Weiss, the head of NJOY, was very open about his company’s aims and challenges last year. “We’re trying to do something very challenging: change a habit that is not only entrenched but one people are willing to take to their grave,” he said.