The active chemical used in spray tans, dihydroxyacetone (DHA), has the potential to cause genetic alterations and DNA damage, according to a panel of medical experts who reviewed 10 of the most-current publicly available scientific studies on DHA for ABC News, including a federal report ABC News obtained through the Freedom of Information Act.
Six medical experts in areas ranging across the fields of dermatology, toxicology and pulmonary medicine said they "have concerns" after reviewing the literature and reports about DHA, the main chemical in the popular "spray-on" tan, which has conventionally been referred to as the "safe" alternative to tanning under ultraviolet lights.
None of the reviewed studies tested on actual human subjects, but some found DHA altered genes of multiple types of cells and organisms when tested in different labs by different scientists after the chemical was approved for use in the consumer market.
"I have concerns," said Dr. Rey Panettieri, a toxicologist and lung specialist at the University of Pennsylvania's Perelman School of Medicine. "The reason I'm concerned is the deposition of the tanning agents into the lungs could really facilitate or aid systemic absorption -- that is, getting into the bloodstream."
Panettieri, like all the experts ABC News consulted with, said more studies should be done. He emphasized the available scientific literature is limited. Still, he said, he has seen enough to say the warning signs of serious health concerns exist.
"These compounds in some cells could actually promote the development of cancers or malignancies," he said, "and if that's the case then we need to be wary of them."
The FDA originally approved DHA for "external" use back in 1977, when it was popular in tanning lotions. Those lotions, previously famous for turning skin orange, were never as popular as current products that produce better tans. In recent years, the use of DHA has exploded in the newer "spray" application of the product, which provides a more even tan for consumers.
The FDA told ABC News it never could have envisioned the chemical's use in spray tan back in the 1970s, and says "DHA should not be inhaled or ingested" today. It tells consumers on its website, "The use of DHA in 'tanning' booths as an all-over spray has not been approved by the FDA, since safety data to support this use has not been submitted to the agency for review and evaluation."
The agency advises consumers who spray tan they are "not protected from the unapproved use of this color additive" if they are inhaling the mist or allowing it to get inside their body. The agency recommends, "Consumers should request measures to protect their eyes and mucous membranes and prevent inhalation."
However, ABC News found some tanning salons offering consumers advice that directly conflicts with what the Food and Drug Administration has recommended.
In response to ABC News' findings, the tanning industry has announced it will launch a major national training initiative that will hit thousands of salons across the United States over the next few weeks, intended to inform both salons and customers who "spray tan" about the FDA recommendations.
Tanning Salons: Undercover Investigation
However, in an attempt to see if that message was reaching consumers, ABC News sent undercover cameras into a dozen randomly selected tanning salons in New York City ranging from a large corporate location to smaller mom-and-pop salons.
Every salon ABC News visited said spray tanning was completely "safe" with or without protective gear.
When asked, nine out of 12 salons did not have any eye covers in stock. Similarly, nine out of 12 salons did not have nose plugs in stock. Eleven out of 12 failed to have any protective gear for the mouth available.
However, even if salons had some of the gear in stock, every salon ABC News visited discouraged using it.
"You don't need it. You really don't need it," one salon employee said.
Another discouraged eye protection, saying it would impact the appearance of the tan.
"We wouldn't recommend for you to wear them because when you spray your face that part is going to be not tan," a salon employee said.
A different salon said, "We also have goggles but you don't need them."
Yet another salon wrongly told undercover ABC News producers that DHA is so safe, it is used to help treat diabetes and can be injected into the body.
The findings by ABC News were enough to convince the industry's top tanning salon trainer to launch the comprehensive national program to reinforce the FDA's safety recommendations.
"As a result of your investigation I will be developing a unit to emphasize training points on the usage of the protective measures by spray tanning clients," said Joe Levy in an email to ABC News.
Levy is the executive director of the International Smart Tan Network, the educational institute for the North American sun bed community.
"I am going to personally review protocol in facilities that are doing this effectively and, based on that assessment, immediately put training in place to improve compliance everywhere," he said.
Levy said his message will go out in several phases over the next few weeks and estimated that it should hit "nearly every salon in the United States."