When it comes to beauty products, few things are so obviously full of chemicals than nail polish and remover.“Who hasn’t walked into a nail salon and been overcome by the stinky punch of undeniable chemicals?” says Jenna Hipp, a “green” celebrity nail stylist in Hollywood, California. “You think to yourself: ‘This can’t good.’ And you’re right.”It’s not just toxic fumes that should raise concern. It’s the ingredients in your nail polish that are proven to be harmful.

“Between the nail, cuticle and the surrounding skin, it’s inevitable that what goes on your nails is absorbed through your blood stream,” says Deborah Burnes, founder and CEO of Sumbody natural beauty line and author of “Look Great, Live Green.”Here are eight terms to brush up on before your next nail appointment.

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“3-Free” = no formaldehyde, toluene or dibutyl phthalate

Formaldehyde is the F-word of manicures—it’s not necessary to use and if it is in your polish, listen up, because there could be serious repercussions. This colorless and strong-smelling gas is not only used in embalming (eek!), it can also be found in countless common household items, including glue, plywood, adhesives and yes, even as a hardener and preservative in nail polish. Oh, and last but not least: It’s a proven carcinogen. In fact, as of June 10, 2011, the U.S. Department of Health and Human Services updated its National Toxicology Program Report on Carcinogens (RoC) to state that formaldehyde is “known to be a human carcinogen,” replacing the previous and more ambiguous “reasonably anticipated to be a human carcinogen.”

Dibutyl phthalate (aka DBP) is a tongue-twister of a name (we dare you—say it three times fast!) for a plasticizer that reduces brittleness and cracking, improving the lasting power of nail lacquer. You might recognize it as referred to as just plain phthalates in other cosmetics. The not-so-complicated downsides: It’s linked to cancer in lab animals, as well as suspected of developmental and fertility concerns in humans, so it’s especially dangerous for pregnant women, says Hipp.

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Toluene helps suspend paint throughout the bottle—which means you don’t have to shake it up very often—plus it gives polish it’s smooth texture, just like it does for other liquids. (Um, as in gasoline and household paint.) Research shows that chronic and extensive exposure to this solvent can affect the central nervous system, cause headaches, dizziness and fatigue as well as possibly act as a reproductive and developmental toxin. The bottom line: Polish may separate quicker when it’s toluene-free, so every few weeks you might have to put some muscle into it and shake things up a bit. (We think you can handle that.)According to Jane Park, founder of Julep Nail Parlor in Seattle, Washington, you won’t even miss dropping the above from your polish vocab. “Polish that doesn’t contain these ingredients stays on nails for as long and is just as shiny as those that do, and you can rest easy knowing that they’re not affecting your health,” she says.

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 “4-Free” = all of the above + no formaldehyde resin

It’s not rocket science: Since formaldehyde is a carcinogen, you don’t want to see any form of that 12-letter word on the label of a product that you’re using weekly. While taking out the aforementioned trifecta of toxins is becoming mainstream, it’s this pesky fourth that’s still lingering. Technically called tosylamide/formaldehyde resin (if you want any info on it, that’s the name you need to search with), it’s a synthetic resin made from combining the chemicals toluenesulfonamide and formaldehyde. It has not been researched enough to concretely show carcinogenic characteristics. However, according to the Environmental Working Group (EWG), it’s classified as an allergen and is a known human immune system toxicant that’s “expected to be toxic or harmful.”

James Hammer, a cosmetic chemist at Mix Solutions in Uxbridge, Massachusetts, doesn’t see a need for concern: “Formaldehyde resin isn’t a problem, since the formaldehyde is chemically reacted and the resin itself isn’t harmful like free formaldehyde is,” he says.However, others argue: Why risk it? “While formaldehyde changes it’s molecular structure upon being turned into resin, there aren’t definitive studies on it’s safety either, and there are plenty of polishes that are leaving it out,” says Nonie Creme, founding creative director of Butter London nail lacquer company.

Vegan = no animal derivatives, by-products or testing

Although the term is commonly associated with extreme foodies who’ve banned all clothing and food that comes from animals in any way, shape or form (as in bye-bye French goat cheese and Italian leather), the same holds true for cosmetics.

“It might sound surprising but there are cosmetic companies that are still using crushed beetle wings to create a metallic or shimmer finish,” says Park, who notes that her Julep line uses aluminum powder to add iridescence instead. Many of the experts interviewed explained that in cosmetics, the use of animal testing or byproducts is no longer prevalent and just because a company doesn’t tout the term “vegan” on their label doesn’t mean they aren’t.

“I think the idea of calling out a nail polish as vegan is ridiculous,” says Burnes. “Two of the largest manufacturers of nail polish aren’t using any animal-related products in their formulas. Almost everything you’re buying is vegan.” Not a fan of even potentially having your fingers covered in beetle juice? We’re with you. Dialing customer service to double check if the polish you’re reaching for is in fact vegan, even if the label doesn’t say so, could totally be worth it.

Natural = the same exact thing as 3- and 4-free

Unless someone figures out a way to whip up a Nobel Prize-worthy liquid pigment derived from say, rose petals, that then magically adheres to nails, an all natural polish is simply not happening.“Natural’ is a term that is overused and is ambiguous when it comes to nail polish,” says Creme. “Even if you take out the ingredients that have been shown to be harmful, the formulation is still chemically based, so it can’t be truly natural—and there’s no shame in having a chemical formulation that’s safe.”

Hey, if there are some natural ingredients in your polish that are doing your nails some extra good (i.e. vitamin E or hydrating natural oils), great, but otherwise, be wary of a company claiming their polish is natural and read the label closely to see what backs up their claim.

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Acetone = highly flammable solvent with an eye-watering smell

Nail polish remover has been traditionally formulated using acetone or ethyl acetate solvent. “These ingredients are flammable, harsh and drying to skin, and generate a lot of fumes, which can irritate the eyes, lungs and skin,” says Hammer.

Hammer suggests looking for less toxic removers that are acetone-free and contain less irritating solvents, including propylene carbonate, ethyl lactate (which comes from corn), methyl soyate (from soybean oil), and d-limonene (from oranges). All of these materials are capable of dissolving polish, although you’ll have to put a few more rubs into in than with acetone-based versions.

Whichever kind you choose to use to wipe away polish, minimize exposure by soaking a cotton pad thoroughly then pressing it onto nails for a few seconds before rubbing. “This technique helps dissolve polish quickly so that you don’t have to use more than you need,” says Hipp. “And always sit in a well-ventilated room or even go outside where there’s plenty of fresh air.”

Benzophenones = UV blocker that prevents color fading

So, you know how after a few days into a beach vacay your freshly painted, shiny and bright nails suddenly turn drab, dull and well, kind of yellow? That’s because just like your beloved highlights are prone to the havoc of oxidization, so is your polish.

That’s exactly why so many companies use benzophenones in an attempt to shield ultraviolet light from degrading polish for as long as possible (it’s also in inks as well as in perfumes and even soaps—and of course the mother of all sun protectors, sunscreens, where it acts as simply a UV light defender). The problem is that there are studies showing that it exhibits estrogen-like effects and is a carcinogen when used in large quantities.Your safest option is to try to keep newly painted nails out of direct sunlight (also good for your skin!) and, if you do anticipate lots of sun exposure, opt for a pale color that won’t fade as noticeably as more vibrant shades.

Camphor = potential irritant that’s totally pointless to have in polish

Why on earth would the same skin-tingling, mint-smelling ingredient used in muscle rubs need to be in your polish? Some nail polish manufacturers are wondering the same exact thing. While some forms are naturally derived from plants, some camphor is produced synthetically from turpentine oil, a harmful and toxic ingredient. Although experts say that the levels found in polish are nowhere near the high amounts that have been studied and linked to negative health effects, “it’s not necessary to have in polishes in any way,” explains Burnes. “So, why risk it?”

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Methanol = a chemical found in some non-acetone polish removers

Recently, there’s been industry buzz on low-levels of methanol being found in non-acetone polishes—and concern that exposure to this ingredient can have negative effects similar to that of acetone (i.e. dizziness, nausea, headaches, etc.).

However, some experts argue that there’s little to worry about because there’s little evidence that trace amounts of methanol are harmful. “Typically, non-acetone nail polish removers are formulated using ethyl acetate, an organic compound that’s formed by reacting ethyl alcohol (ethanol) with acetic acid, in a process called etherification,” explains Hammer. “As a result, sometimes there are trace amounts of ethanol present, but no methanol is used in this process, and methanol is not intentionally added as an ingredient.”In other words, if any methanol is present in a acetone-free nail polish remover, it must be at extremely low levels, probably parts per billion. “You can find levels higher than that naturally occurring in fruits and vegetables,” says Hammer.

CONTINUE READING: The Best Non-Toxic Nail Polishes