A little more than a month ago, Duane Reade pharmacies in New York started selling light blue aerosol cans containing "99 percent breathing oxygen." The product comes with a mask, a set of instructions — basically point at your nose and inhale — as well as some chirpy promises: "Refresh! Revive! Rejuvenate!"

A little more than a month ago, Duane Reade pharmacies in New York started selling light blue aerosol cans containing "99 percent breathing oxygen." The product comes with a mask, a set of instructions — basically point at your nose and inhale — as well as some chirpy promises: "Refresh! Revive! Rejuvenate!"

No doubt a certain percentage of jaded New York shoppers have looked at this seemingly empty, eight-ounce tube of pressurized air and thought, "Why would I spend $16 for something I'm getting for free right now?" Or, "This is some kind of joke, right?"

Kevin DelGaudio, the creator of Instant Oxygen, would like to field those questions. A 45-year-old entrepreneur and former hardware store manager, DelGaudio is sitting on a bar stool at the Tribeca Grill, waving his hands a lot and speaking in a thick Brooklyn accent as he evangelizes about the benefits of canned oxygen.

"It's a very misunderstood gas," he says.

If the third-most-abundant element in the universe ever had a Johnny Appleseed, here he is, although there are some notable differences between DelGaudio and the famous 19th-century planter.

Only, whereas Appleseed emphasized charity and altruism, DelGaudio would like to make a killing.

Which he confidently predicts he will make — although that hardly seems like a sure thing, at least with this particular item. DelGaudio belongs to that singular class of American schemer-dreamers who either retire rich or wind up with the word "cockamamie" in their obituaries.

"About 80 percent of Americans are oxygen-deficient," DelGaudio says, citing the first of several statistics he claims to have found on the Internet. "Now, how can that be if there is enough oxygen in the air?"

DelGaudio came up with Instant Oxygen in Las Vegas in 2004, after spending 30 minutes at an oxygen bar near a trade show he was attending. Then working for a company that imports light bulbs, he was looking for a new venture and knew he'd found something special.

"I literally bounced out of bed, which I don't usually do," he recalls. "I felt great, and the only thing different is that I'd been breathing pure oxygen the day before."

DelGaudio found a couple of smallish companies selling oxygen cans online, but their products didn't impress him — one cost $50 per can; the other you breathe in through your mouth, which he found uncomfortable — and neither was in stores. Whenever someone argued that the canned-oxygen market was tiny because oxygen in cans is a lousy idea, DelGaudio had two words: bottled water.

"The analogies are amazing," he says. "When that started, people said, 'You think someone is going to spend $2 for water when they can get 10 and a half gallons for a penny out of the tap?' "

He opened a fabrication plant in Spotswood, N.J., where oxygen he buys in bulk from a company in Delaware — yes, it's Delaware oxygen, not New Jersey oxygen — is packed into cans. It took 11/2 years and "just over $1 million," he says, to get this business started. He has three investors and a number of employees, though he won't say how many for competitive reasons.

He won't discuss sales figures, either, nor would a spokeswoman for Duane Reade, the only chain so far to carry the product. Aside from claiming that sales have "exceeded expectations," DelGaudio won't elaborate.

"Have you seen the product?" he asks, pulling a can out of his bag. He removes the cap, twists the top 90 degrees and puts his nose into the face mask. Then he presses down on the top.

Pffft goes the can.

"If you hold it down continuously," he says, now holding his breath like a stoner who's just hit a bong, "it's about four and a half minutes of oxygen."

The benefits of canned oxygen include an increase in energy and a cure for hangovers, he says. But it's bigger than that.

DelGaudio's case for oxygen spans history and disciplines, and it includes a claim that Earth's atmosphere — which is 21 percent oxygen — contains much less oxygen than it did even a few hundred years ago. He blames this on deforestation and the rise of the industrial economy, or as he succinctly puts it: "More factories, less oxygen. More processed food, less oxygen in your body. You don't need a doctor to figure that out."

Martin Feuer, a physician and the former chairman of the pulmonary medicine department of Beth Israel Medical Center listened to a description of Instant Oxygen, then let out a somewhat contemptuous sigh.

"There just aren't any physiological benefits to breathing oxygen," he said. "If you don't have enough oxygen in your brain for even a minute, you're in bad trouble. So the body has an amazingly efficient system to keep the flow of oxygen going."

Doctors are dismissive, to put it mildly, of canned oxygen. Some will say it can help athletes catch their breath, which is why you'll see football players on the sidelines breathing oxygen. And oxygen is used to treat such illnesses as asthma and emphysema. But if you're healthy and not trying to recuperate from a sprint or two, breathing oxygen for recreational purposes, for a few minutes, won't have any effect, good or bad.

DelGaudio thinks doctors are simply uninformed when it comes to the benefits of oxygen, noting that few spend any significant time on the subject in medical school. But more important — and he underscores this a few times — he isn't making any health claims about his product.

"Some people aren't going to have any reaction to this product," DelGaudio warns. "Other people will tell me, 'I just ran three miles, and I never have run more than two.' "