How Worried Should I Be About Toxins in Nail Polish?

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There are nail-polish brands that have made ingredient no-no lists part of their marketing strategy with labels claiming a particular number of things their product is “free” from. It started in the aughts with “3-free” polish and, since then, has continued to steadily climb: 5-free, 7-free, 10-free, and, recently spotted, 21-free. All of which raises the question: Why do we need our nail polish to be free of ingredients? What does the proliferation of these “nontoxic” brands say about what could be lurking in traditional nail polish?

As it turns out, not much: These polish brands one-upping each other with higher “free” numbers are counting ingredients that are often never included in nail polish to begin with. “It’s morphed into a numbers game,” says Vivian Valenty, a cosmetic chemist and founder of nail brand Dazzle Dry, of this polish greenwashing. For example, parabens were never in nail polish formulas yet still are included in these “free from” tallies. “Another example would be acetone, which is typically used to remove nail polish but not found in it to begin with,” says Dan Werner, head of R&D at polish brand Orly. Same goes for sodium lauryl sulfate, gluten, nonylphenol ethoxylates, and many others.

The nail-polish ingredients broadly accepted as being problematic are often dubbed the “toxic trio.” First, there’s formaldehyde, which, says Dr. Dana Stern, a New York– and Southampton-based dermatologist who specializes in nail issues, is a known carcinogen that has been linked to asthma, neurotoxicity, and developmental toxicity (which can cause structural or functional abnormalities). In cosmetic formulations, it can go by different names including methylene glycol, formalin, methanol, methanediol, and formaldehyde monohydrate. But no matter what it’s called, formaldehyde in its carcinogenic form isn’t in most nail polish (though it is in nail hardeners; to avoid it entirely, get one like Barielle Nail Strengthener Cream, Jinsoon HyperRepair, or Ten Over Ten the Rehab, which are formulated without it). “What is found in nail lacquer is formaldehyde resin,” says Werner. The resin (also known as tosylamide), while not carcinogenic like free formaldehyde, is still a contact allergen that can cause redness, swelling, and itching, says Valenty. (Dazzle Dry uses no form of it in its products).

A lawsuit in the 1990s by environmental consumer group As You Sow against the Cosmetics, Toiletries, and Fragrance Association drew attention to the second “toxic trio” ingredient: toluene (which also goes by toluol, methylbenzene, and phenyl methane). It’s a petrochemical solvent used to dry polish that is considered toxic to the immune system.

The lawsuit was settled with manufacturers agreeing to use toluene only at concentrations below 50 percent, but once attention was brought to the ingredient, most polish-makers phased it out completely. “Public opinion matters,” Valenty says.

And finally there’s dibutyl phthalate, or DBP, which Stern says is part of a class of plasticizing chemicals used to make products more pliable and to prevent chipping. While phthalates have the potential to disrupt the endocrine system and cause birth defects, the level of exposure a nail-polish consumer or salon customer has to these chemicals is challenging to pinpoint. Stern thinks we should still be mindful. “Where there is smoke, there is fire,” she says. “We know that these chemicals are associated with risks, but it’s difficult to quantify the risks.” Stern adds that other nail-polish chemicals to be wary of are camphor (a plasticizer that can cause headaches and nausea when inhaled), triphenyl phosphate (a plasticizer that’s also an endocrine disruptor), xylene (a solvent that prevents polish lumpiness and is a known allergen and carcinogen), and ethyl tosylamide (a plasticizer that’s already banned from cosmetic use in Europe). Werner also has styrene-based copolymers (ones that are “nano,” not “non-nano”) on his watch list.

Now, while all these chemicals and their potential side effects sound downright terrifying, here’s the deal: Most of them are not found in the polishes at nail salons from mainstream brands such as Essie, OPI, Orly, Zoya, and Deborah Lippmann. “The majority of all the chemicals used now are all compliant with either FDA or E.U. regulations,” says Werner, adding that U.S. companies rely on the FDA list of banned ingredients for cosmetic use to guide polish development. And they look to the E.U. as well because, Werner says, it is often at the forefront of regulation. But, he adds, that same ingredient compliance may not extend to the many small brands out there, particularly given the size of the global online marketplace for nail polish.

For the polishes that claim to be water based (often they are the ones marketed to kids, like Piggy Paint), preservatives should be on the ingredient list. “Water-based products should contain preservatives to prevent bacteria, yeast, and fungal growth and ensure their safety,” Valenty advises. Piggy Paint uses neem oil as its preservative.

If you want to look closer at the chemical content of your nail polish, Werner points to the updated list of chemicals attached to California’s Proposition 65 (a law passed by ballot initiative in the state that requires businesses and manufacturers to alert consumers to the presence of and exposure to certain chemicals) as a good reference point. “If it is a Prop 65 material, it could pose a risk,” he adds. PubChem and EWG’s Skin Deep List are other resources for chemical-content fact-checking. Most brands will have their ingredients listed on the package (though concentrations are not required to be published, Stern adds), and some brands, including Deborah Lippmann, make those lists readily available on their websites. If a brand doesn’t have its ingredients listed, contact the company; they are obligated to provide it. Because the recently passed Modernization of Cosmetics Regulation Act considers ingredients used in nail polishes as cosmetics, Valenty says, it will require brands to comply with certain manufacturing practices by 2025. Until now, the onus has been on the brand to ensure its products do not cause harm to consumers. For those wary of taking on any risk of chemical exposure, Stern says you probably shouldn’t be wearing polish, period. “All polishes have some chemicals,” she says.

When it comes to assessing the risks of nail polish, Stern says to consider how they’re being taken in. “It is unlikely that significant volumes are absorbed through the nail plate, but contact with skin and inhalation are more concerning,” she adds. Werner agrees, underscoring that the real problem posed by these chemicals comes via the vapors. That is why getting into the habit of using nail lacquer (any nail lacquer, even the ones without the aforementioned ingredients) in a well-ventilated area — meaning a space with good airflow and fans or open windows (if you’re unsure, wear a mask) — is simply good practice. Those who should be the most diligent about taking the proper precautions? Nail-salon workers.

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How Worried Should I Be About Toxins in Nail Polish?