NANO SILVER BULLET

Your toothpaste may be a pesticide. So might your electric razor, your computer keyboard, and your child's teddy bear. These products, and scores of others, combine one of the world's oldest disinfectants--silver--with one of its hottest new industries: nanotechnology. The manufacturers of these products boast that they fight bacteria, molds, and fungus. Therefore, according to the U.S. Environmental Protection Agency (EPA), these products may be pesticides. Though this may sound like a Rush Limbaugh story line about paranoid eco-Nazis, the reality is that we're lacing ordinary household goods with known toxins. And until scientific testing and federal laws catch up with this new technology, we may be exposing the environment--and our own bodies--to untold harm.

The new science of nanotechnology allows manufacturers to use materials that measure between 1 and 100 nanometers. (A nanometer is a billionth of a meter, or roughly 1/100,000 the width of a human hair.) While nanoparticles can occur naturally and by accident--in diesel soot, for example--it's only in the past decade or so that scientists have widely learned to create and manipulate them. Many nanotechnologies use nano-versions of common materials, like carbon and silver. These tiny particles take on almost magical qualities: Insoluble materials can become soluble, nonconductive substances start conducting electricity. Nanomaterials can be orders of magnitude more powerful than the same substance at normal scale. Myriad green applications are in the works, and medical miracles are promised.

For now, though, nanotech is largely used in industrial and consumer products, from cosmetics to fleece to plastic food containers. Often, the benefits are more convenient than essential: White sunscreen turns clear on the skin; fabrics resist stains and static; leftovers stay fresh longer. There are over 600 nano consumer products on the market today--up from about 200 two years ago, when the Washington-based Project on Emerging Nanotechnologies (PEN) started keeping an inventory--with three to four new products added weekly.