Gel nail polish banned by EU is still used in U.S. An expert weighs in.

The European Union’s ban this week of a popular type of gel nail polish shouldn't panic Long Islanders who get manicures, but they might want to be careful about how it's used, an expert said.

The EU Monday began implementing a prohibition of trimethylbenzoyl diphenylphosphine oxide, TPO, in cosmetic products. TPO is used to dry and harden polish, allowing nail treatments to last longer. Studies on rats indicated  the chemical can damage male reproductive systems, affecting fertility, and irritate the skin.

Based on current research, people receiving manicures shouldn’t "immediately be concerned," said John Moses, a professor of click chemistry at Cold Spring Harbor Laboratory in Cold Spring Harbor.

Exposure from ultraviolet light used in gel polish manicures breaks up most of the TPO, and what’s left is solid and encapsulated in the thick cover of polish, he said.

"Ingesting or leeching into the body is the potential concern, but if it’s isolated in the nail, the risk is attenuated significantly," Moses said.

He recommended against biting nails that are covered in gel polish containing TPO.

During manicures, fingertips with gel nail polish containing TPO are put under ultraviolet lamps, and the combination of the UV light and the TPO triggers a chain reaction of molecules that quickly hardens the polish, Moses said.

TPO isn’t the only chemical that can create such a reaction, he said.

"There are other activators that might be used," he said.

"I don’t think it’s devastating for the industry," he said, adding that he didn’t know if alternatives cost more or could pose other problems for salons.

Three New York organizations advocating for better health protections for nail-salon workers and two groups representing nail salon owners did not respond to requests for comment Wednesday.

The EU action bans cosmetic products with TPO in its 27 member countries; several other European countries follow EU guidelines.

There have not been TPO studies on humans. The EU does not classify TPO under a category that includes substances "for which there is clear evidence that they are carcinogenic, mutagenic or toxic to reproduction." Instead, it is classified as a substance where the effects are possible, but "there is a need for further research." That was enough to institute the ban.

The New York State Department of Health said in a statement it "is always evaluating the safety of chemicals used in certain cosmetic products" but that it "aligns state regulations with federal guidance when considering potential health risks."

The U.S. government often is less stringent in environmental and health regulations than the EU, but current Health and Human Services Secretary Robert F. Kennedy Jr. has cited stricter EU regulations when discussing potential negative health effects of chemicals allowed in the United States. Other federal agencies in President Donald Trump’s first and current terms weakened regulations on chemicals.

HHS, parent agency of the Food and Drug Administration, which has limited authority over cosmetics safety, did not respond to requests for comment.

Moses said although none of the studies done so far were on humans, it’s reasonable to be careful about the use of TPO, although he said he didn’t have an opinion on whether the EU decision was correct.

"If there are alternatives that are known to be safer and there’s a red flag risk, then what’s the real damage?" he asked.

By David Olson

david.olson@newsday.com@DavidOlson11

David Olson covers health care. He has worked at Newsday since 2015 and previously covered immigration, multicultural issues and religion at The Press-Enterprise in Southern California.