One tanning salon employee ABC News visited undercover, the lead trainer for a large corporate chain of salons in New York, told undercover television producers that DHA is "super safe," and, "great for pregnant women," something Goldman disagreed with.
Goldman is a pediatrician appointed by President Clinton and approved by the Senate to serve in a top position at the EPA overseeing chemical safety. She has since left the position and gone back to university work. Her experience in both public health science and government gives her an unusual perspective which bridges both health and regulatory issues.
"I think a lot of people assume that because things are on the market that it means somebody has very carefully evaluated them and that they're safe," she said.
She was concerned about DHA mainly on two fronts -- firstly, because of the new information scientists have learned about DHA since it was approved for use in the 1970s. She believed the information was strong enough to warrant a full review of the product's safety that takes into account all potential health implications.
Secondly, she said, the explosion in DHA's use in spray tanning means many more people will be exposed to it in a manner that has never been subject to an FDA safety review.
"The use is expanding and it doesn't prompt a re-evaluation," she said, "and I think that's a serious problem."
Dr. Panettieri, the lung specialist, agreed.
He told ABC News he believes the dose from an individual spray tan or two is likely low enough to not have a demonstrable impact on someone's health. But he would definitely "have concerns" for those who regularly spray tan, week after week.
He was especially concerned for tanning salon workers who apply 15 to 20 spray tans a day without wearing protections, thinking the mist is "safe."
Panettieri noted that the lungs have an unusually large surface area and are built to absorb oxygen and distribute it throughout the body. They will do the same thing with chemicals like DHA that reach them, he said -- and unlike the skin, the lungs do not have a protective layer.
Panettieri's review of studies ABC News provided and his own review of published scientific papers showed that no long-term tests of DHA's effects on lungs have ever been performed.
Like Goldman, he was worried not only about cancer but also other health effects that can be caused from mutations in DNA.
"These compounds in some cells could actually promote the development of cancers or malignancies, and if that's the case then we need to be wary of them," he said. "And in this case, there are more than just [one] instance that this compound was associated with toxicity. So when you put all the evidence together, the concern exists."
Panettieri was mostly concerned about long-term exposures. He said problems might not immediately arise after shorter exposures, saying that even if large amounts of DHA were applied in a few applications to the lungs, it might not cause immediate problems.
"Frankly, right now, given the evidence I've seen, it's time to pursue this question in a more rigorous fashion and really answer: Is it safe or not?" he said.
The industry points to a ruling from 2010 by the European Commission that found DHA, as used in spray tan facilities, is safe for consumers. The European Commission provides guidance to the European Union on a variety of matters, including health.
Panettieri, Goldman and Rigel pointed to flaws and limitations they saw in the European review of DHA.
The European review took place after the cosmetics industry in Europe chose evidence for the European Commission to review, according to the commission. Because the cosmetics industry selected the evidence, nearly every report the commission's eventual opinion referenced came from studies that were never published, never peer-reviewed and, in the majority of cases, were performed by companies or industry groups linked to the manufacturing of DHA -- entities that had a financial incentive to see the chemical widely used.
Panettieri noted an additional flaw that he called "artful": The cosmetics industry, in asking the European Commission to review DHA, left out nearly all of the peer-reviewed studies published in publicly available scientific journals that identified DHA as a potential mutagen.
Goldman, through a spokeswoman, said the European report did not have all bad information but "did not contain information from peer-reviewed literature and is, therefore, not thorough."
Dr. Arthur Grollman, a toxicologist at Stony Brook University in New York, agreed, saying the European review was "flawed" and "incomplete."
Joe Levy of the International Smart Tan Network presented ABC News a critique of one of the more recently published studies that concerned experts. The study, published in the scientific journal "Mutation Research" in 2004, found that DHA as used in sunless tanners "damages DNA." Levy provided ABC News with a letter written by a Merck KAag scientist in late May 2012 criticizing the study.
Merck KAag is the largest manufacturer of DHA, Levy said.