Traditional nail polish is widely used for cosmetic purposes, but its chemical composition presents a significant fire hazard. The liquid form of traditional nail lacquer is highly flammable and can be easily ignited when exposed to a heat source or flame. Understanding the science behind this flammability, which involves both liquid solvents and solid film-formers, is crucial for adopting safer handling and storage practices. This knowledge is crucial because the risk extends beyond the liquid in the bottle to the vapors released during application.
Chemical Components Causing Flammability
The flammability of nail polish is directly linked to the blend of solvents and film-forming polymers necessary for its function. Approximately 70% to 80% of a typical nail polish formula consists of volatile solvents like ethyl acetate and butyl acetate. These compounds dissolve the other ingredients and allow the polish to spread smoothly, but their highly volatile nature means they evaporate quickly and are extremely flammable.
Once the solvents evaporate, the primary film-former remains, which is often nitrocellulose, a highly combustible polymer. Nitrocellulose is chemically derived from treating cellulose fibers with nitric and sulfuric acids, a process that transforms the material into a fast-drying, glossy film. The presence of both volatile, flammable liquids (solvents) and a highly flammable solid (nitrocellulose) in the formula creates a dual fire hazard.
Flammability Classification and Vapor Risk
The primary danger of nail polish flammability comes not just from the liquid but from the invisible vapors it emits. Nail polish is classified as a Class 2 Flammable Liquid, often carrying the hazard statement H225: “Highly flammable liquid and vapor.” This classification is determined by the product’s flash point. The flash point is the lowest temperature at which the liquid gives off enough vapor to form an ignitable mixture with the air.
The solvents in nail polish, such as the acetates, have very low flash points, often significantly below average room temperature. They produce flammable vapors easily. These volatile organic compound (VOC) vapors are heavier than air and can travel along surfaces to reach a distant ignition source, such as a pilot light or a spark. The vapors can then flash back to the source of the liquid. This vapor travel is often a greater risk than the polish liquid catching fire, emphasizing the importance of ventilation during application. The risk decreases once the polish is completely dry, as the flammable solvents have evaporated, leaving behind the cured, solid film.
Essential Safety Practices for Handling and Storage
Handling nail polish safely requires minimizing the exposure of flammable vapors to heat or ignition sources. During application, ensuring excellent ventilation is the most important practice. This disperses the flammable vapors and prevents them from accumulating or traveling to a distant flame. Keep the open bottle away from all potential ignition sources, including lit cigarettes, candles, space heaters, or any device that generates a spark.
For storage, bottles must be kept away from direct sunlight, heat sources, and any hot surface. The container should be stored vertically with the cap tightly sealed to prevent the slow release of vapors. In the event of a fire, using a dry chemical or carbon dioxide extinguisher is recommended for a nitrocellulose solution. Consumers should never pour unwanted polish down the drain or into the trash; it must be disposed of according to local hazardous waste collection guidelines.
Nail Polish Removers and UV Gels
The flammability risk extends to related nail products, particularly nail polish removers. Acetone-based removers are extremely flammable, possessing a flash point as low as 5°F (-15°C), making them highly volatile even in cool conditions. Non-acetone removers, which often contain ethyl acetate or other solvents, are still flammable but may be less volatile than pure acetone.
UV-cured gel polishes present a different flammability profile. The finished, cured gel on the nail is generally not considered flammable. However, the liquid form of the uncured product, composed of monomers and oligomers, is often combustible and must be handled with similar care to traditional lacquer. The liquid components, particularly the uncured monomers, are often classified as highly reactive materials. These products should be stored away from any open flame.