Can nail polish still be applied if it dissolves foam boards?
Chemicals in nail polish are toxic. Occasional manicures pose no harm, but prolonged use can cause nails to yellow or darken.
Background Information
US study reveals multiple nail polishes contain toxins
According to Legal Evening News,Recently, the California Department of Toxic Substances Control (DTSC) released an investigation report indicating that among 25 randomly sampled nail polish products, 12 featured falsified labels—claiming to be free of toxic substances when in fact they contained hazardous chemicals including dibutyl phthalate (DBP), toluene, and formaldehyde.The report emphasized that while the use of toluene and DBP in nail polish is not illegal, falsifying labels is.
DTSC investigations revealed that 10 out of 12 nail polish products claiming to be "toluene-free" actually contained this toxin. Among 7 products claiming to be free of all three toxins, 5 were verified to have inaccurate labeling.
Surprisingly to DTSC, products claiming to be toluene-free often contained higher levels of toxins. The report states that California attorneys are considering whether to prosecute manufacturers for mislabeling.
Exposure to chemicals like dibutyl phthalate (DBP), toluene, and formaldehyde may cause chronic illnesses such as cancer and asthma, or affect fetal development, placing nail salon employees and customers at potential risk.
Test Materials
The reporter randomly purchased three bottles of ordinary colored nail polish from the market: one red nail polish from Di×× Cosmetics Co., Ltd. (2 yuan), one blue nail polish from Jinhua City ×× Cosmetics Co., Ltd. (2 yuan),both bearing the QS mark but lacking ingredient lists or manufacturer addresses; one bottle of clear nail polish branded B×× (¥3, with packaging entirely in English—translated as "Vitamin Natural Nail Polish"—and no QS mark);Additionally purchased at a cosmetics chain store: one 18ml nude-colored nail polish (¥12, outer packaging labeled: benzene-free, acetone-free); at a department store nail polish counter: one 5ml Ba×× Fleur Fragrance Eco-Friendly Nail Polish (¥42, bearing QS mark, production license number, and health permit number); one foam plastic board.
Experimental Guidance
Chen Xiaofeng, Chief Physician, Department of Dermatology, Shenyang Seventh People's Hospital
Ge Ying, Chemistry Teacher, Shenyang No. 47 Middle School
Experimental Procedure
Apply all five nail polishes sequentially onto the same foam board. Allow to air dry after application. Observe changes in the foam board to determine whether the five nail polishes exhibit corrosive effects on the foam.
Experimental Results
Nail Polish "Burns" Holes in Foam Board
After 10 minutes, the reporter observed varying degrees of corrosion on the foam board from the first four bottles.Among them, the clear nail polish exhibited the strongest corrosive power, penetrating deepest into the foam board. Upon application, a strong chemical reaction occurred: bubbles formed on the foam surface accompanied by a hissing sound, ultimately leaving a "small pit" on the foam board.Next were the red and blue standard colored polishes, which also severely corroded the foam board. The so-called "benzene-free, acetone-free" nude-colored polish showed comparable corrosion to the red and blue polishes, with little difference. Finally, the natural plant-based eco-friendly polish caused only minor corrosion to the foam board.
Is this really the case? Among the female friends of our reporter, many have embraced nail polish as an indispensable accessory in their lives, proclaiming that "being a refined woman starts with your nails!" Furthermore, online rumors claim nail polish can "corrode" foam plastic. Is it truly that toxic, rendering it unsuitable for human use?This episode of "People's Laboratory" tests nail polish's corrosiveness to reveal its chemical composition, its potential health impacts, and whether it's safe for application.
Results and Analysis
Not "Corrosion" but Dissolution
Why does nail polish "corrode" foam plastic?
The reporter interviewed Ge Ying, a chemistry teacher at Shenyang No. 47 Middle School, on this issue.
She explained that the pitting on the foam board isn't true corrosion, but rather dissolution caused by organic solvents in the nail polish. Nail polish is a cosmetic synthesized using nitrocellulose as a base, combined with chemical solvents like acetone, ethyl acetate, and butyl phthalate.Foam plastic, primarily composed of polystyrene, is also an organic material easily dissolved by various organic solvents like ethyl acetate and acetone. Thus, while the foam board appears corroded in the experiment, it is actually dissolved by the organic solvents in the nail polish.
Higher Organic Solvent Content Equals Greater Toxicity
While this experiment isn't quantitative, it provides qualitative insights. The extent of foam dissolution indicates the organic solvent content in nail polish. Organic solvents are often toxic—the higher the concentration, the greater the toxicity.
The reporter's experiment also confirmed findings consistent with the California Environmental Protection Agency's conclusions: many nail polishes feature falsified labels solely to command higher prices. For example, a nude-colored nail polish purchased from a cosmetics chain (labeled "benzene-free, acetone-free") similarly "corroded" the foam in testing, proving it contained significant organic solvents.
Expert Advice
Occasional Use Won't "Corrode" Nails
Chen Xiaofeng, Chief Physician of Dermatology at Shenyang Seventh People's Hospital, explained that foam's composition, structure, and hardness are incomparable to human nails. Therefore, one shouldn't develop fear of nail polish simply because it "corrodes" plastic foam.
Human nails consist of four layers from outer to inner: the nail plate, nail bed, nail root, and nail matrix. The nail plate—the outermost layer commonly referred to as the nail—is where nail polish directly contacts. It comprises three to four overlapping layers of hard keratinous scales composed of protein, keratin, and calcium (containing no capillaries or nerves).It has low solubility in the organic solvents used in nail polish, so occasional use does not "corrode" the nail.
Minimize manicures; remove polish within 2-3 days
The primary purpose of applying nail polish is aesthetic; it offers no protective benefits to the nails. Conversely, the toxic effects of substances in nail polish—such as formaldehyde, acetone, and dibutyl phthalate (DBP)—cannot be overlooked.These substances strongly irritate the respiratory and nervous systems, so nail polish should ideally be applied in well-ventilated rooms or outdoors. The surface layer of human nails naturally possesses a protective coating. Prolonged nail polish use damages this protective layer, causing loss of shine, pigmentation, yellowing, darkening, and even paronychia. Therefore, it is advisable to minimize nail polish application.Chen Xiaofeng also recommends removing nail polish within 2-3 days after application. Follow up by applying olive oil for a week to nourish the nails. Nail polish should not be worn continuously for extended periods. Avoid cheap street vendor products Natural nail polishes pose slightly less harm than conventional ones, but no nail polish is entirely natural.When selecting nail polish, opt for products from reputable manufacturers. Avoid cheap, unregulated street-vendor products or "three-no" items (no production date, no manufacturer, no quality certification). After applying nail polish, exercise caution when eating to prevent ingesting toxins.Never apply nail polish on broken skin or when cuticles are irritated, as this can cause infection. Individuals whose work requires prolonged finger immersion in water should avoid nail polish, as it intensifies chemical irritation to nails and skin. Those with skin allergies, pregnant women, and children should refrain from using nail polish.