The terms “non-toxic”, “vegan”, “cruelty-free” and “wellness” appear on an increasing number of nail salon websites and polish bottles. But unlike food or pharmaceutical products, the cosmetics industry in the United States operates with minimal pre-market regulation — which means these labels are largely self-declared and not independently verified before products reach shelves.
This guide explains what the science and regulation actually say, so you can make informed decisions when choosing a nail salon or polish brand.
- How nail products are regulated in the USA
- The chemicals that matter — and what the evidence says
- What X-free labels actually mean
- Vegan vs cruelty-free vs non-toxic: three different standards
- The occupational health context: nail salon workers
- How to identify a genuinely clean nail salon
- Tools for independent verification
1. How nail products are regulated in the USA
Nail polish and nail care products are classified as cosmetics under the Federal Food, Drug, and Cosmetic Act (FD&C Act) and are regulated by the U.S. Food and Drug Administration (FDA). However, the regulatory structure for cosmetics differs significantly from drugs or food.
According to the FDA, cosmetic products — including nail polish — do not require FDA approval before they enter the market, except for most color additives. The FDA can take action against non-compliant cosmetics after they are on the market, but does not conduct pre-market safety reviews of formulas or ingredients. FDA
The 2022 Modernization of Cosmetics Regulation Act (MoCRA) expanded FDA authority over cosmetics for the first time since 1938, requiring manufacturers to register their facilities and disclose serious adverse events. However, it does not establish pre-market approval requirements for cosmetic ingredients.
The contrast with the European Union is significant. The EU Cosmetics Regulation (EC 1223/2009) prohibits or restricts over 2,800 substances in cosmetic products. The EU applies a precautionary principle — substances suspected of being carcinogenic, mutagenic, or harmful to reproduction (CMR substances) are restricted even before definitive human evidence is established. CHEM Trust
A notable recent example: as of September 1, 2025, the EU banned trimethylbenzoyl diphenylphosphine oxide (TPO) — a photoinitiator widely used in gel nail polishes — after classifying it as a reproductive toxicant and skin sensitizer. TPO remains permitted in the United States. CNN
2. The chemicals that matter — and what the evidence says
The following table covers the ingredients most commonly referenced in non-toxic nail care discussions, with their function in the formula and the nature of the documented health concerns. Sources are official bodies and peer-reviewed publications only.
| Ingredient | Function in nail polish | Documented concern | Regulatory status |
|---|---|---|---|
| Formaldehyde | Hardener; prevents bacterial growth | Classified as a human carcinogen (Group 1) by the International Agency for Research on Cancer (IARC/WHO), linked to nasopharyngeal cancer and leukemia. Also classified as “known human carcinogen” by the U.S. National Toxicology Program (NTP) and as “carcinogenic to humans by inhalation” by the EPA. American Cancer Society | Banned in EU cosmetics. Permitted in the USA with no concentration limit in nail hardeners; must be listed on label. Also appears as formalin or methylene glycol. FDA |
| Toluene | Solvent; creates smooth application | Neurotoxicant at high doses. At occupational exposure levels, linked to headaches, dizziness, and central nervous system effects. The NIOSH recommended exposure limit (REL) is 100 ppm as a ceiling concentration. CDC/NIOSH | Restricted in EU cosmetics. Permitted in the USA. Air samples at nail salons studied by NIOSH did not exceed current exposure limits, though the study authors noted ventilation as a significant factor. NIOSH |
| Dibutyl Phthalate (DBP) | Plasticizer; prevents chipping | Endocrine disruptor. Classified as a Category 1B reproductive toxicant in the EU (evidence of reproductive toxicity in humans or animals). Linked to developmental harm, particularly concerning during pregnancy. PubMed/NIH | Banned in EU cosmetics since 2004. Permitted in the USA; on California Prop 65 list as a developmental toxicant. Still detected in some US products labeled “DBP-free” in independent testing. PubMed/NIH |
| TPHP (Triphenyl Phosphate) | Plasticizer; replaced DBP in many formulas | Suspected endocrine disruptor. A 2016 study published in Environment International by researchers at Duke University, Boston University, and EWG found that TPHP metabolites increased nearly sevenfold in the urine of all 26 female participants within 10–14 hours of applying nail polish containing TPHP. The primary exposure route was identified as dermal (skin contact during application). PubMed | Not banned in the USA or EU as of 2025. Listed as an ingredient in approximately half of nail polishes tested in the study; two products contained TPHP without listing it on the label. Removed by brands at 7-free and above. EWG |
| Camphor | Plasticizer; adds glossy finish | Can cause skin irritation and allergic reactions. Toxic if ingested in large quantities. Listed as a concern by the FDA for nail products. FDA | Permitted in the USA and EU at low concentrations. Typically removed in 5-free and above formulas. |
| Ethyl Tosylamide | Film former; improves adhesion | Classified as a reproductive toxicant by EU regulators. Banned from cosmetics in the EU due to concerns about antimicrobial resistance (it is used as an antibiotic in some contexts). PubMed/NIH | Banned in EU cosmetics. Permitted in the USA. Typically removed at 7-free and above. |
| Formaldehyde Resin (TSFR) | Hardener; improves durability and adhesion | A byproduct of formaldehyde. The FDA notes there is evidence that some people may become allergic to TSFR. Most common cause of allergic contact dermatitis attributed to nail polish. FDA | Permitted in the USA and EU. Typically removed at 5-free and above. |
| TPO (Trimethylbenzoyl Diphenylphosphine Oxide) | Photoinitiator in gel polishes; enables UV/LED curing | Classified as a reproductive toxicant and skin sensitizer by EU regulators following animal studies. CHEM Trust | Banned in EU cosmetics from September 2025. Permitted in the USA; no FDA action expected in the near term per cosmetic chemists quoted by CNN. CNN |
3. What X-free labels actually mean
The “X-free” numbering system originated in the early 2000s when nail polish manufacturers began voluntarily removing the three most criticized chemicals — formaldehyde, toluene, and DBP — and marketing products as “3-free.” The EU’s 2004 ban of DBP from cosmetics accelerated this shift among brands selling internationally.
A 2018 study published in Environmental Science & Technology (PubMed/NIH) tested 40 nail polishes from 12 brands and found that “regrettable substitution” is common — when one concerning chemical is removed, brands sometimes replace it with another that carries similar risks. DBP’s replacement by TPHP is the most documented example. PubMed/NIH
| Label | What is removed | Common brands at this level |
|---|---|---|
| 3-free | Formaldehyde, Toluene, DBP — the “toxic trio” | Entry level; most mainstream brands today |
| 5-free | + Camphor, Formaldehyde Resin | Widely available |
| 7-free | + Ethyl Tosylamide, Xylene | Mid-range clean brands |
| 9–10-free | + TPHP, Parabens, and often animal-derived ingredients | OPI (reformulated lines), Zoya, Manucurist, Côte, Addiction Tokyo |
| 15–17-free | + Additional allergens, BHA, synthetic fragrances, certain preservatives | Olive & June (15-free), Sally Hansen Good.Kind.Pure (16-free), Ella+Mila (17-free) |
| 21-free | + Benzene, Hydroquinone, Cyclic Silicones, Bismuth Oxychloride, Glycol Ethers, Carcinogenic Mutagenic Substances, and others | Londontown, Nails.INC, Deborah Lippmann, HABIT, Liberation Nails |
The higher the number, the more ingredients have been removed — but the list of excluded chemicals varies between brands at the same level. Two polishes both labeled “10-free” may exclude different sets of ingredients. Always check the brand’s specific exclusion list, not just the number.
4. Vegan vs cruelty-free vs non-toxic: three different standards
These three terms are frequently used interchangeably in marketing, but they address entirely different concerns. A product can meet one without meeting the others.
Non-toxic / X-free
Vegan
Cruelty-free
Animal-derived ingredients commonly found in conventional nail polish
The following ingredients are derived from animals and are absent from vegan formulas. Their names on ingredient labels are not always intuitive. The Vegan Society, in their guide to vegan nail polish, identifies these as the most common: The Vegan Society
| Ingredient | Label names | Origin | Function |
|---|---|---|---|
| Guanine | Pearl essence, CI 75170, natural pearl essence | Fish scales (herring, menhaden, sardine) | Shimmer and pearlescent effect |
| Carmine | Cochineal, crimson lake, natural red 4, CI 75470 | Dried and crushed female cochineal insects | Red pigment |
| Shellac | Lac resin, shellac resin | Secretion of lac bugs (Kerria lacca) | Gloss and film formation |
| Lanolin | Wool wax, wool fat | Secretion from sheep wool | Moisturizing agent |
| Beeswax | Cera alba | Honeybees | Thickening agent |
| Keratin | Hydrolyzed keratin | Cattle, horses, pigs, feathers | Strengthening; nail treatment |
| Squalene (animal-derived) | Squalene, squalane (when animal-sourced) | Shark liver oil (plant-derived alternatives exist) | Moisturizing; emollient |
Vegan alternatives exist for all of these ingredients. Mica (a naturally occurring mineral) replaces guanine for shimmer effects. Synthetic or plant-derived dyes replace carmine for red pigments. The substitution does not affect performance in quality formulations.
5. The occupational health context: nail salon workers
The strongest evidence for health risks from nail salon chemicals comes from occupational health research on nail technicians — workers with sustained, daily chemical exposure — not from occasional client use. This context is important when evaluating risk claims.
The National Institute for Occupational Safety and Health (NIOSH), part of the CDC, has conducted research on nail salon worker health for over a decade. A 2019 scoping review of 29 peer-reviewed publications, produced with Johns Hopkins Bloomberg School of Public Health, found consistent evidence that working in hair and nail salons may increase the risk of respiratory effects. Evidence on reproductive effects was described as insufficient to draw definitive conclusions, though prior studies raised concern. CDC/NIOSH — Johns Hopkins
A 2021 NIOSH Science Bulletin noted that nail technicians and hairdressers are exposed to dozens of chemicals — including acrylates, parabens, phthalates, toluene, and formaldehyde — some of which are associated with cancer or reproductive harm. The bulletin highlighted that most of these workers are women of reproductive age, many of them foreign-born, representing a vulnerable occupational population with limited labor protections. CDC/NIOSH
A NIOSH Health Hazard Evaluation at four nail salons found that some personal formaldehyde concentrations exceeded the NIOSH recommended exposure limit, and that employees worked in ergonomic positions associated with musculoskeletal disorders. No personal air samples for toluene, ethyl acetate, or methacrylates exceeded limits at those specific locations. CDC/NIOSH
NIOSH recommendations for nail salon environments include local exhaust ventilation at workstations, gloves when handling chemicals, and general room ventilation. These recommendations apply to workers, but also create a safer environment for clients. CDC/NIOSH
6. How to identify a genuinely clean nail salon
Given that “non-toxic”, “wellness”, and “clean” are unregulated marketing terms, the following are verifiable signals — things you can observe before or during a visit.
At reputable wellness salons, the polish brand is displayed at the service station. Brands like Zoya (10-free), Ella+Mila (17-free), Manucurist (9-free), Londontown (21-free), or Deborah Lippmann (21-free) are verifiable against their published ingredient lists. Ask to see the bottle before the technician opens it.
NIOSH identifies local exhaust ventilation at workstations as the most effective control for chemical exposure. Look for table-mounted ventilation units, ceiling exhaust fans, or air filtration systems near service stations. The absence of a chemical smell is a secondary indicator (some low-odor formulas are not clean, and some clean formulas have mild scents).
Leaping Bunny (cruelty-free, verified by Cruelty Free International), PETA Beauty Without Bunnies, or The Vegan Society Trademark are independently verified. Self-declared “vegan” or “cruelty-free” claims without these marks are unverified.
Autoclaved metal implements or individually sealed single-use disposable tools. This is a basic hygiene standard that applies to all salons regardless of wellness positioning, but its presence is a reliable indicator of overall professional standards.
A genuinely clean salon should be able to name the polish brands they use, confirm whether they are vegan, and specify which formulas they stock. Vague answers like “we use the best products” without brand names are a caution sign.
Hand creams, cuticle oils, and soaks at wellness salons typically use botanical ingredients — jojoba oil, shea butter, essential oils. Products that cannot be identified (unlabeled bottles, generic creams) should prompt questions.
7. Tools for independent verification
The following free resources allow you to verify the safety profile of specific cosmetic ingredients and products independently, without relying on brand marketing claims.
- EWG Skin Deep® Cosmetics Database — rates individual cosmetic products and ingredients based on hazard level, using peer-reviewed research and regulatory data. Maintained by the Environmental Working Group, a US nonprofit.
- FDA — Nail Care Products — official FDA overview of safety issues in nail products, including formaldehyde, toluene, and methacrylates.
- CDC/NIOSH — Nail Technicians: Workplace Safety and Health — comprehensive resource on chemical hazards, ventilation recommendations, and research findings from the National Institute for Occupational Safety and Health.
- Leaping Bunny (Cruelty Free International) — searchable database of certified cruelty-free brands. The most rigorous cruelty-free standard, requiring third-party audit of the entire supply chain.
- The Vegan Society Trademark — certification standard and registered brand database for vegan products.
- PETA Beauty Without Bunnies — searchable database of cruelty-free brands; also includes a vegan subset. Note: PETA’s standard does not require supply chain audits, making it less rigorous than Leaping Bunny for cruelty-free verification.
- PubMed — “Nail polish as a source of exposure to triphenyl phosphate” (Mendelsohn et al., Environment International, 2016) — peer-reviewed study from Duke University on TPHP absorption through nail polish application.
