Are there any risks associated with the use of nail polish?

Whether it's for a special occasion or a simple daily indulgence, painting one's nails is a habit deeply ingrained in many people's routines. However, behind this seemingly harmless act, there are several questions about the potential health risks it poses. Indeed, between inhaling potentially toxic fumes, skin absorption of chemical substances, and effects on the nail structure, several issues deserve to be addressed. The first problem posed by nail polishes is their high allergenic potential. Indeed, it's not uncommon for nail polishes to cause redness and itching around the nails, or even on other parts of the body due to accidental transfer, especially in people with atopic skin. These allergies are particularly common with semi-permanent polishes.

Moreover, while nail polish application beautifies the nails, it can paradoxically weaken them over time. Several factors contribute to this effect, including chronic exposure to resins and plasticizers found in polishes, which can alter the structure of the nail's keratin. Solvents, essential in a nail polish formula for quick drying, can also alter the nail's natural lipids as they evaporate, making it drier and more brittle. This is one of the reasons why it is advised not to continuously apply manicures and to take breaks.

However, the real danger posed by nail polish is the inhalation of its fumes. As soon as a bottle is opened, a strong odor escapes, indicating the presence of volatile organic compounds. These are the solvents in nail polish. While they allow the polish to dry quickly by evaporating into the air, they are inadvertently inhaled. Occasional exposure is not necessarily dangerous, but repeated and prolonged inhalation can be problematic. Indeed, in poorly ventilated environments, the volatile solvents in nail polish can cause respiratory irritations, headaches, and dizziness, especially with frequent use. These effects are even more pronounced for beauty professionals, who are exposed daily to the emissions of polish and removers, increasing the risk of chronic respiratory disorders.

A study assessed the exposure of nail salon workers to volatile organic compounds using five types of nail polish among the most popular in the United States. The simulated scenario involved applying polish to 32 nails every 15 minutes during an 8-hour workday, in a test chamber with controlled airflow. The results revealed that the concentrations of butyl acetate (161-330 ppm) and ethyl acetate (440 ppm) exceeded safety thresholds (respectively 150 ppm and 400 ppm). Additionally, formaldehyde was present at concentrations ranging from 0.12 to 0.22 ppm, above the limit of 0.10 ppm. This highlights the high exposure risks to these potentially dangerous volatile solvents in nail salons and underscores the need to increase ventilation and raise worker awareness about the hazards associated with these products.

The occasional use of nail polish in a home setting is not inherently dangerous, but prolonged exposure in a professional context raises more concerns.

The concerns raised by nail polishes stem from the ingredients used to formulate them. Here is an overview of the most common molecules in nail polishes and their potential risks.

• Acetone : Acetone is one of the most commonly used solvents in nail polish, as it allows for the rapid dissolution of the formula and promotes quick drying. However, acetone is highly volatile and irritating to the skin, eyes, and respiratory tract. Prolonged exposure to this solvent can dry out the nail, cause skin irritations, and neurotoxic effects, such as headaches, dizziness, and nausea.

• Toluene : Toluene is another solvent frequently used in nail polishes. However, it poses health risks. It is considered toxic to the central nervous system and can lead to symptoms such as dizziness, nausea, and headaches when inhaled. Additionally, it is suspected to be carcinogenic and to have harmful effects on fetal development and fertility.

• Formaldehyde : Formaldehyde is frequently used in nail polishes to strengthen the nail structure. However, this compound is classified as a "possible human carcinogen" in Europe and is considered a potential endocrine disruptor.

• Butyl Acetate : Butyl Acetate is a solvent often added to varnishes to provide a fluid texture. Although it is less hazardous than acetone, it can still irritate the skin and respiratory tract. High-dose inhalation can also cause headaches, dizziness, and nausea.

• Dibutyl Phthalate (DBP) : This is a plasticizer used to make nail polishes more supple and flexible. However, this compound is an endocrine disruptor, exposure to which is linked to fertility issues. Although more and more brands have removed it from their formulas, it is still present in some products.

• Parabens : The parabens are preservatives that can potentially cause irritation and allergic reactions, and are suspected to be endocrine disruptors. They are found in many personal care products, including nail polish.

• Camphor : Camphor is an ingredient used in certain varnishes to provide a flexible texture. Although it is relatively safe at low doses, prolonged exposure to camphor can cause respiratory irritation, headaches, and dizziness. At high doses, camphor is also considered toxic to the nervous system.

• Xylene : Xylene is a solvent used to achieve a smooth and fluid consistency in nail polishes. However, it also acts as an irritant to the skin and respiratory tract. With prolonged exposure, xylene can cause damage to the liver, kidneys, and central nervous system.

• Styrene : Styrene is used in some nail polishes to enhance their adherence to the nail. However, since 2019, the International Agency for Research on Cancer (IARC) has classified it in Group 2A as a probable human carcinogen.

• Rosin : Rosin is a natural resin sometimes added to varnishes to enhance their adhesion. However, its inhalation is associated with the occurrence of respiratory issues.

In response to growing concerns about the ingredients found in nail polishes, an increasing number of brands are turning to alternatives that aim to be safer and more health-conscious. This is particularly true for those offering "free-from" formulations (3-free, 5-free, 7-free, etc). "3-free" nail polishes do not contain toluene, formaldehyde, or dibutyl phthalate. "5-free" products go a step further by also excluding acetone and camphor, while "7-free" and "10-free" formulations eliminate even more ingredients, such as butyl acetate, styrene, or parabens. These polishes are often considered interesting alternatives for pregnant women.

Despite the benefits of these nail polishes, it's crucial to emphasize that no nail polish is entirely risk-free. Indeed, terms like "3-free", "5-free", or "7-free" do not adhere to a universally established standard, making it challenging to guarantee the safety of these products. This was particularly demonstrated in a 2018 study that examined the composition of 40 "free" nail polishes from 12 different brands. The figure below illustrates the lack of uniformity among the various "free" nail polishes.

If you want to ensure that a nail polish does not contain a certain substance, the only way is to carefully read its INCI list.

• CEBALLOS D. M. & al. Phthalate and Organophosphate Plasticizers in Nail Polish: Evaluation of Labels and Ingredients. Environmental Science & Technology (2018).

• OH J. & al. Laboratory Estimation of Occupational Exposures to Volatile Organic Compounds During Nail Polish Application. Workplace Health & Safety (2019).

• PAIVA LUZ P. & al. Nail Polishes: A Review on Composition, Presence of Toxic Components, and Inadequate Labeling. Dermatology, Research and Practice (2025).