Nail polish comes in many forms and colors, and it can be used to add embellishment or simply to protect the nails from moisture. It is usually sold in liquid form and applied to the nail with a small brush, then quickly hardens, providing a waterproof seal. It can be removed manually by using nail polish remover and should last several days before chipping or peeling.
In its earliest form, nail polish was worn only by the royalty and other members of high society, who would apply beeswax mixed with gelatin and dyed with orchids or roses to the fingernails. This type of nail color tended to fade after a few hours, but it was a great way to show off one’s wealth and status. In the late nineteenth century, nail polish began to be mass-produced in a variety of colors and textures by the cosmetic industry. Today’s nail polish is a much more sophisticated product and contains a variety of ingredients, including film-forming agents, resins and plasticizers, solvents, and coloring agents. The exact formula of a particular brand of nail polish is generally a trade secret, but the FDA has lists of approved pigments and other chemicals that can be used in a nail polish. The choice of ingredients greatly impacts the quality of the final product.
The main ingredient in modern nail polish is nitrocellulose, a chemical that gives the finished product its strength and durability. Other important ingredients are resins and plasticizers, which help the nitrocellulose adhere to the nails. They also reduce the tendency of a nail polish to crack or chip by embedding themselves in polymer chains and increasing the distance between them. Common resins and plasticizers include tosylamide-formaldehyde resin and camphor.
Solvents are necessary to dissolve the other ingredients and allow them to be applied to the nails, and they also act as a carrier for the colored pigments. Early polishes contained soluble dyes, but most nail products today contain dry, powdered pigments that are mixed with the other ingredients to create the desired color.
Some people are concerned that the use of nail polish may be harmful, especially if the polish is used often or left on for extended periods of time. However, the evidence supporting these concerns is limited and inconclusive (1). Regardless, it is possible to find nail polish that is free of many potentially toxic chemicals. Some polishes have been formulated without the plasticizer dibutyl phthalate, which has been linked to endocrine system disorders.
Some nail polishes also claim to contain a variety of other health-promoting or beauty-enhancing ingredients. For example, some brands of nail polish contain garlic to strengthen nails and prevent splitting. Others claim to have cucumber extract for a soft, smooth finish. Vernis à ongles