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You probably wouldn’t expect to find pesticides in your toothpaste or your gym socks, but they might be in there all the same. And the vast majority of those pesticides have made it into everyday products without adequate oversight by the Environmental Protection Agency. That’s because they’ve been approved through a bureaucratic loophole known as “conditional registration,” which means they haven’t been fully tested to ensure that they pose no threat to human health or the environment, as required by U.S. law.

Most of us think of pesticides as the chemicals that get sprayed on weeds or used to kill rodents and bugs, but they’re actually found in everything from cosmetics to food containers, as well as antimicrobial textiles (such as the exercise shirt you might have worn to the gym this morning). By killing bacteria and other microorganisms, pesticides can help clothes resist stains or help containers keep food fresh longer. But some have also proven to cause health concerns in humans, kill trees, birds, bees, and fish, or do other unintended harm to the environment.

The EPA has been responsible for registering pesticides since 1972, and during that time, 90,000 have been allowed on the market. A significant number of those — just over 25,000, according to the EPA — were initially approved through the conditional registration process. An internal report by the EPA’s Office of Pesticide Programs shows that of the more than 16,000 pesticides allowed on the market as of 2010, about 11,000 of them were conditionally registered. Because of the agency’s poor record-keeping and flawed procedures, it remains unclear how many of these conditionally registered pesticides have ever gone through the full gamut of safety testing required by law.

“The dirty little secret of the EPA is that almost every pesticide gets put on the market while the agency is looking the other way,” says Michael Hansen, a senior staff scientist at Consumers Union. “That’s not good for consumers, and it’s not the intent of the regulations.”

By law, in order to register and sell a pesticide, companies are supposed to go through a process than can last several years; it includes public comment, reviews of scientific studies, and evaluations by the agency’s in-house science experts. The fast-track conditional registration process was intended to be used only under rare circumstances — when a product is nearly identical to one already on the market, for instance, or when the EPA needs to approve a new pesticide immediately to prevent a disease outbreak or other public health emergency (a new treatment for bedbugs, for example).

No one knew the extent to which the EPA had been abusing the conditional registration rules until 2008, when the Natural Resources Defense Council (which publishes OnEarth) began asking questions about why nanosilver, an antimicrobial made of extremely tiny bits of silver and used to kill bacteria in products such as athletic gear and baby blankets, had been granted conditional registration.