Take a Powder

If there's anything the cosmetic industry loves, it's a new type of product to hype, and recently, companies have flocked to mineral makeup powders. But are they worth the fuss?

Back in the 1970s, the FDA approved many minerals for use as pigments in cosmetics. But what's new about the latest powders is that minerals are promoted as if they're virtually the only ingredients. And it's true that many contain little more than zinc oxide (ZO), titanium dioxide (TiO2), mica and iron oxides.

Furthermore, "Powders in general tend to have less irritants, less preservatives, less oils and less surfactants and as a consequence are less likely to cause irritant dermatitis or plug your pores," says Stephen Mandy, M.D., clinical professor of dermatology at the University of Miami.

Do read labels carefully. As there is no set definition for the term "mineral makeup," any product that contains minerals as a primary ingredient may be touted as such, although it may also contain some unhealthy chemicals.

Nano or Not?

New health concerns are arising with regard to the size of particles in some cosmetics. Some powders are made up of micron-sized (one-millionth of a meter) particles that may be inhaled during application. Other mineral makeups employ ZO and TiO2 nanoparticles (billionths of a meter), which may pose health risks, recent research shows. A study in the June 2006 Environmental Science and Technology found that TiO2 particles ranging in size from 826 nanometers (nm) to 2,368 nm might enter the brain, causing oxidative stress.

Fortunately, many mineral makeup companies—but by no means all—keep their particle sizes larger in order to retain the color and light-reflecting properties of the minerals. With one exception, the companies listed below use particles of 7 microns (7,000 nm) or more, which makes them "too large to cross the blood-brain barrier," says Günter Oberdörster, Ph.D., professor of environmental medicine at the University of Rochester School of Medicine and Dentistry. While powders aren't absorbed by the skin, according to Mandy, particles smaller than 7 microns are able to penetrate deep into the lungs, Oberdörster says.