Nail polish
Nail polish is a liquid coating applied to fingernails or toenails that dries into a colored, glossy, or protective film.
Film-forming polymer: A polymer that forms a continuous, adherent layer as a coating dries. Nitrocellulose and related polymers create the solid film left on the nail.
Gel nail polish: A nail coating that hardens through light-initiated polymerization. It is a long-wearing polish type cured under a lamp rather than dried mainly by evaporation.
Nail plate: The hard, visible keratin structure that forms most of a fingernail or toenail. It is the surface on which polish forms its coating.
Contact dermatitis: Skin inflammation caused by direct contact with an irritant or allergen. Nail product ingredients can trigger dermatitis, sometimes on skin touched by the hands.
Nitrocellulose: A cellulose derivative used in lacquers, coatings, and other products. It is a principal film-former in many conventional nail polishes.
Shellac (nail product): A branded hybrid nail coating combining features of nail polish and gel systems. Its salon service illustrates a branded alternative to conventional lacquer.
Keratin: A family of structural proteins found in hair, nails, and the outer layer of skin. Nail plates are made chiefly of keratin, shaping the coating's substrate.
Toluene: A volatile aromatic solvent used in some coatings and industrial products. It has been used as a nail-polish solvent and is a focus of exposure concerns.
Volatile solvent: A liquid that evaporates readily under ordinary conditions. Solvents keep polish fluid in the bottle and evaporate after application.
Nail art: The decoration of fingernails or toenails using color, patterns, and applied materials. Polish serves as a base and medium for decorative designs.