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Nail Polish Comes Under Fire in New Study

The Environmental Working Group today released a joint study with Duke University about a suspected endocrine-disrupting chemical, Triphenyl phosphate or TPHP, in nail polish.

The nail polish industry once again finds itself under the microscope for chemicals used in formulas.

The Washington-based Environmental Working Group today released a joint study with Duke University, presenting evidence that a suspected endocrine-disrupting chemical, Triphenyl phosphate or TPHP, is ending up in women’s bodies.

The peer-reviewed study was published yesterday in Environment International.

Their concern is that the chemical — used as a flame retardant but also as a plasticizer in nail color to provide strength and flexibility — raises health concerns such as obesity and early puberty. TPHP has caused reproductive and developmental problems in animal studies, according to the watchdog group.

Researchers found evidence of the suspected endocrine-disrupting chemical in the bodies of more than two dozen women who participated in a biomonitoring study.

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“The question is whether or not we should be buying products with this ingredient if we know it is getting into our bodies. Nail polish was a contributor to the exposure,” said Johanna Congleton, senior scientist for EWG.

But Beth Lange, chief scientist for the Personal Care Products Council, quickly responded and challenged the fear. “American consumers should not be concerned by new research that is speculative, misleading and does not use sound science to access the safety of an ingredient which has a long and well-documented history of use.” She added that TPHP has been widely and safely used across many industries around the world, especially as a flame retardant.

Biometric studies showing widespread exposure prompted EWG to look at TPHP’s use beyond the electrical, automobile and furniture industries. “Along the way, we noticed it was also an ingredient in some nail polishes,” said Congleton. “We began to wonder if that could be contributing to the exposure because all of the biometric data showed it was fairly widespread.”

They set out to see if people were exposed via nail polish, and if so, how. Women painted their nails, normally followed by urine collection and testing, and then used polish while wearing gloves applied to synthetic nails. The result was somewhat surprising, since the nails are thought to be fairly impermeable to most molecules, said Congleton. But the levels of diphenyl phosphate, which forms when the body metabolizes TPHP, increased sevenfold within 10 to 14 hours, with the direct application suggesting the chemicals permeate nails.

Gillian Palette, a board certified adult nurse practitioner specializing in cosmetic dermatology and esthetics, noted that nails are porous. “What we put on them does matter,” she said. “But nail polish penetrating through the nail into the body on its own is unlikely to harm us. That said, TPHP is a plasticizer that can be toxic to humans, but I am more inclined to worry about the cumulative effects rather than just pinpointing exposure from one.” She added, however, that it is hard to pinpoint TPHP exposure and that there is the need for more research as repeated exposure is likely to produce cumulative health issues. “The bottom line, we need to be more aware of the chemicals that surround us as well as the ones we apply on our nails and skin.”

According to EWG’s Skin Deep cosmetics database, more than 1,500 nail products include TPHP. That translates to 49 percent of the 3,000 polishes and treatments compiled by the database. The list includes Sally Hansen, Essie, OPI, Butter London, Revlon, Milani, Wet ‘n’ Wild, Milani, Spa Ritual, Orly, The Balm, Nuance by Salma Hayek, Maybelline and Beauty Without Cruelty. There are some polishes, experts said, that currently don’t disclose TPHP. The Duke-EWG research did identify the chemical in eight out of 10 test polishes in which two of the eight did not list the ingredient on the labels. And, said one manufacturer asking for anonymity, some of the polishes are the rapidly growing gel-like formulas.

This isn’t the first time nail polish has come under the microscope — toluene and dibutyl phthalate (DBP) have previously been fingered as harmful to users. Most nail products sold today do not use these in formulations. In fact, in some cases, TPHP was tapped to replace phthalates. “It is possible that TPHP is now being used in nail polish as a replacement for phthalates, which also have endocrine-disruptor properties and are toxic to the reproductive system, said Heather Stapleton, associate professor at Duke University and the principal investigator of the Duke-EWG study. “But it’s not clear that TPHP is the better alternative. There is growing evidence suggesting TPHP may affect hormone regulation, metabolism, reproduction and development.”

The EWG enacted a petition to urge companies using TPHP to remove it.

Nail-polish manufacturers contacted by WWD deferred to PCPC. The association’s Lange added that under the U.S. Food and Drug Administration regulations, TPHP, like all cosmetic product ingredients, must be safe for the intended use. She referenced that international scientific experts have completed extensive reviews on the safety of TPHP and that studies have determined the ingredient does not present a concern for human health.

She also pointed out that TPHP, as noted in the EWG study, is rapidly transformed. “Therefore infrequent use of nail products would not represent a significant source of TPHP in the body,” she said. Data from other biomonitoring studies show the chemical in men and women, casting some controversy into the nail polish claim.

“Clearly, there is no substance behind these alarming claims. The makers of nail polish stand behind their products and take pride in providing Americans with access to a wide variety of safe, high-quality and innovative products they trust and enjoy,” Lange concluded.