ACS Chemistry for Life

The key ingredient in nail polish is nitrocellulose, a long-lasting, film-forming agent derived from cellulose. But before nitrocellulose was put into nail polish, it was used as a component of automobile paint by chemists at DuPont. Shortly after the car paint’s 1920 debut, nail enamel formulations containing nitrocellulose appeared in patent literature. The patents detail the deposit of a pigment-impregnated film on finger- and toenails just as on car surfaces. The nitrocellulose-containing paint was initially so popular that within four years it covered all of General Motors’ cars. The auto industry has long since moved on to other coatings, says DuPont spokesman Rick Straitman. But nitrocellulose, which is also a component in fireworks known as “gun cotton,” remains a constituent of many nail polishes today.

Nail polish was not a new idea in the 1920s, although in terms of technology, the period marked a “quantum leap in both formula and production,” says history of science expert Gwen Kay at the State University of New York, Oswego. Records from 17th- and 18th-century European royal courts document the appearance of shiny, varnished nails, she says. In addition, 19th-century recipe books from both Britain and the U.S. contain instructions for making nail paints alongside recipes for bread.

The modern formula isn’t likely to be in cookbooks because the ingredients aren’t exactly tasty. According to Paul Bryson, director of research and development at professional nail care company OPI Products, nail polish also contains adhesive polymers, such as tosylamide-formaldehyde resin, that ensure the adherence of nitrocellulose to the nail surface. Plasticizers, such as camphor, embed between polymer chains, spacing them such that the polish is flexible and will not easily crack or chip.

Visit “What’s That Stuff?” to learn more about nail polish.

Excerpted with permission, Chemical & Engineering News
Copyright © 2008 American Chemical Society