Magicians hold details in high regard, so it’s fair to inquire about one of the key details related to stunt artist David Blaine’s feat that begins today at Pier 54 in New York City’s West Village: How will Blaine’s team handle all the excess ozone gas produced with each million-volt discharge from the Tesla coils?

For three days and nights, Blaine plans to stand atop a six-meter-tall pillar while Tesla coils, controlled by spectators, zap him with electricity. Paul Hoffman, chief executive of the Liberty Science Center, where Blaine is magician-in-residence, estimates one million volts will reach Blaine at any time. The Brooklyn-based endurance performer hopes to survive the Tesla coils—worth about $5 million and donated by software giant Intel--with a protective steel chain-mail suit and metal head cage, which will direct the flow of current around, not through him.

But as those electrical discharges zap the air, they will separate oxygen molecules, which can then rejoin as O3, or ozone, an reactive toxic gas.* Ozone, with its fresh, tingling scent, is a Dr. Jekyll and Mr. Hyde fume. Up in the stratosphere, it protects Earth's life by shielding harmful ultraviolet rays produced by the sun. On the ground, however, it’s smog that the Environmental Protection Agency (EPA) regulates. Although an exact mathematical equation to determine the amount of ozone is hard to produce, atmospheric scientists agree that the magic show could potentially raise the ambient levels of ozone around the pier.

The concern of creating excess ozone is “extremely reasonable,” says Renyi Zhang, an atmospheric scientist at Texas A&M University. “ I saw the [promotional] photo and I thought, wow, he will create a lot of ozone.”

A team on the ground will measure ozone levels around Blaine. Those attending the event in New York will be able to stand about 9 meters away from the pillar, Hoffman says. The EPA recommends the public avoid concentrations of ozone up to 75 parts per billion for longer than eight hours, because longer exposure can irritate a person’s airways and cause lung corrosion.* During a test run in a Brooklyn warehouse, Hoffman says that “ozone built up, I could feel it. I have asthma, and my throat got irritated.” The team is counting on the breezy Hudson River setting to keep a healthy mix of fresh air around the event’s venue.

Blaine’s experiment, in addition to sparking public awareness about electrical conductivity, is also a reason to remind the public that ozone on the ground can be harmful, especially indoors. Besides ozone’s direct effects on the lungs, studies have shown it reacts in various ways with our bodies and can become more toxic if it meets other floating particles, such as those created by cleaning liquids. So consumers should be wary of personal ozone generators marketed by manufacturers as ionic air purifiers. “In the U.S., we have a general mindset that says if things are being sold on the market, then we assume it’s safe for us,” says Michael Waring, an environmental engineer at Drexel University.

Last year Waring led a team of researchers to show that an ion generator can produce harmful levels of ozone in a residential room. Yet, despite this and other literature dating from 1913 on the potential harm of ozone, the devices still remain on the market. The EPA devotes a special section on its Web site warning consumers of potential dangers of these devices. Waring says the current indoor air standards set ozone limits to between 50 and 100 parts per billion.* “But that’s a very shaky policy because various things will influence what ozone concentrations will be achieved by these devices,” such as how well a home is insulated, he adds.

For his part, Hoffman says he is not worried about spectators breathing in too much ozone thanks to the expected Hudson breeze. But watchers may want to take note when the unmistakable, deceptively clean-smelling ozone smell wafts over the pier.

*Correction (10/9/12): The three asterisked sentences in this article were edited after posting to correct errors. In the first, the word "unstable" was changed to "reactive." In the subsequent two, references to "parts per million" were changed to "parts per billion."