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What is Big 3-Free, 4-Free and 5-Free Nail Polish Chemicals?

Guide to Big 3, 4 & 5 Free Nail Polish

Nail polish is unfortunately filled with a lot of chemicals, which I’m sure we all know just by the smell alone. But some chemicals in nail polish are more harmful than others – both to our bodies and to the environment. That’s why recently there has a been a lot of talk about “Big 3/4/5 Free” nail polish. These polishes don’t have as many of the “harmful” chemicals that some other brands contain.

Lab Technician Using Pipette

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Are the Chemicals in Nail Polish Bad for You?

It’s debatable. Some would argue that the amount of any toxic chemicals found in nail polish is not enough to cause harm, while others disagree that any amount is unnecessary and harmful to not just the wearer, but the environment as well. Since the amount of any of these chemicals is highly regulated, the health risk is probably small. On the other hand independent testing has shown some not-so-honest labeling on nail polish and also shed light that while some brands listed these harmful chemicals, they did not actually contain them.

Since everybody is different and can react differently to different chemicals it’s important to be smart. Specific concerns might be:

  • Allergy to any of the listed chemicals, or moderate to severe general allergies
  • Developing children
  • Compromised immune systems
  • Pregnant (and nursing) women
  • Sensitive skin or immune system

I think that most nail polish is safe for most consumers, even the nail polish fanatic that owns over 1,000 bottles and paints her nails daily. But another concern regarding chemicals in nail polish is that these toxins are used in salons and manufacturing plants where workers are exposed to higher concentrations which puts them at greater risk. Factories also have an environmental impact as well.

I believe everyone needs to decide for themselves – based off of an aware and educated point of view. Hopefully this post can help with that last part.

Big Free Polish Application

What is Big-3 Free Nail Polish?

Also known as the “Toxic Trio”, big-3 free nail polishes do not contain the following three chemicals:

  • Dibutyl Phthalate (DBP) – Common plasticizer, which increases the flexibility and fluidity of a product.
    • Uses – Makes nail polish last longer by making it more flexible and is used in cosmetics and the manufacture of soft plastics.
    • Safety – Linked to cancer. Health concerns include problems in the endocrine system, increased risk of diabetes in women, nausea, it’s an irritant, causes reproductive issues and has been linked to birth defects.
  • **Formaldehyde – Naturally occurring organic compound that is a gas at room temperature.
    • Uses – Embalmer, nail hardener, preservative, sterilizer, wood component (although its use in wood is now minimized and legislated).
    • Safety – Known carcinogen – meaning causes cancer. Health concerns include allergic reactions, breathing issues (coughing, asthma-like symptoms, wheezing, etc.), it’s an irritant, linked to lung and nasal cancers.
    • Additional Concerns – “In view of its widespread use, toxicity and volatility, exposure to formaldehyde is a significant consideration for human health.” (US Department of Health and Human Services)
  • **Methylene Glycol/Formalin – An organic compound of a solution in water of formaldehyde.
    • Uses – Embalmer, disinfectant, nail hardener, production of plastic and resins, and wart treatment.
    • Safety – Known carcinogen. Highly flammable. Health concerns include allergic reactions, breathing issues (coughing, asthma-like symptoms, wheezing, etc.),  it’s an irritant, and can cause vomiting. At higher levels it can cause bronchitis and fluid in the lungs, but not at the levels found in nail polish.
  • Toluene – Derived from petroleum and commonly used as a solvent to dissolve or combine other chemicals.
    • Uses – Fuel, makes nail polish smooth and even and controls it’s evaporation, and used as a solvent (such as in paint thinner).
    • Safety – Health concerns include dizziness, dry skin, it’s an irritant, casues headaches, liver and kidney damage, nausea, numbness, and has been linked to birth defects.

** Note About Formaldehyde – During my research for this article, I found information that when formaldehyde is listed as a chemical, it is usually referring to methylene glycol, also known as formalin, which I also listed above. I’m not sure if this is 100% accurate but I’m inclined to believe it since formaldehyde is a gas and cannot actually exist in liquid form (nail polish).

According to NAILS Magazine:

The concern over formaldehyde started because the International Nomenclature of Cosmetic Ingredients (INCI), which is a dictionary that instructs the cosmetic industry on how to name chemicals, misnamed a chemical called methylene glycol (also known as formalin) and incorrectly required manufacturers to call it formaldehyde. Though methylene glycol is made from formaldehyde, they are not similar at all…So in effect, the concern over formaldehyde was non-existent because formaldehyde was never used in polishes; it was methylene glycol all along.

However, one does NOT seem to be any better than the other.

According to Wikipedia:

Commercial solutions of formaldehyde in water, commonly called formol or formalin…is commonly used in nail hardeners and/or nail varnish.

Additional Information: Many sites claim that these chemicals have been banned in Europe but this does not appear to be true (International Bans on Formaldehyde).

What is Big-4 and Big-5 Free Nail Polish?

Big-4 nail polishes are those that do not have one of the following chemicals, while big-5 free will have neither:

  • Formaldehyde Resin (Tosylamide/TSFR) – A polymer (synthetic resin) used as a plasticizer or suspending agent.
    • Uses – Ensures nail polish adhesion, adds depth, gloss, hardness and durability.
    • Safety – According to GoodGuide it does not pose any health concern, but others list it as a toxin. Health concerns may include allergic reaction and it can be an irritant.
  • Camphor – A waxy substance from certain trees that smells good and is used as a plasticizer.
    • Uses – Embalmer, explosives, culinary ingredient, nail polish plasticizer – making it more flexible and last longer, medicinal uses, and even used in religious ceremonies.
    • Safety – Highly flammable. Health concerns include dizziness, headaches, and nausea. In high amounts (not found in polish) it can be poisonous, an irritant, cause seizures and even unconsciousness.

Other Common Chemicals In Nail Polish

This is a list of other commonly found ingredients in many nail polishes:

  • Benzophenone – Used as a stabilizer to resist color changes when exposed to light.
  • Butyl Acetate – An organic solvent used to make everything mix together (flammable).
  • Dyes and pigments
  • Ethyl Acetate – An organic solvent used to make everything mix together.
  • Isopropyl Alcohol – Also known as “rubbing alcohol”.
  • Nitrocellulose – Type of lacquer used because it is inexpensive, dries quickly, and it is not damaging to the skin (flammable).
  • Opalescent pigments:
    • Aluminum Powder
    • Mica – Ground up natural minerals.
    • Pearls
  • Stearalkonium Hectorite – A natural mineral in powder form used as a thickening agent, for suspension, and to keep ingredients together.

Big-3, 4 and 5 Free Nail Polish Brand Lists

Here are a few lists I found online of nail polish brands that are big-3, big-4, big-5 free, and even vegan and water based brands:

I cannot personally guarantee the accuracy of any of these brand lists. Please be an informed consumer and do your research. Most brands list information about chemicals and cruelty-free policies in their FAQs section.

References and Resources


  1. Hi there Arden! Greetings from Australia!
    Thanks so much for the pingback. This is such a thoroughly researched piece. I’m so excited to see more people are aware of the toxicity of their personal care products and knowing that greener choices are there – have you personally used any of these toxin-free brands? Which one is your fave so far?

    • Hi Juliet!

      Thanks so much! These kinds of posts take a bit of time but I always learn SO much. I have used a few brands and my favorites so far are Zoya, Opi, China Glaze, Orly and of course Sally Hansen. I have at least 20 bottles of each, lol!

  2. I have looked into the formaldehyde in nail polish issue and there’s a decent consensus that the tiny amount that does volatile isn’t even in the harmful molecule form becuase there are different reactions happening and the original liquid form of the formdehyde like you mention. Bravo on mentioning the worker conditions when considering polishes 🙂

    • Hey Chelsea,

      Yes, thank you! The “formaldehyde issue” threw me for a loop at first and then down an internet rabbit hole of research. And I tried to cover all bases, lol. 😉

  3. Pingback: Nail Care before Nail Art

    • Hi Christine! Yes, I believe that all polish is flammable although water based nail polishes might be an exception (usually marked to children and now there are some eco-water-based polish brands). Hope that helps.

  4. Pingback: The Down Low on Nail Polish - Her Everyday Life

  5. Pingback: Safe Nail Polish Brands: Which Do You Choose? - Turning the Clock Back

  6. Thank you for very useful information. It is a pity that not all manufacturers are honest. I read that Polish varnishes lead to damage to the nails.

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