The EPA has changed its mind on the safety a widely-used pesticide, aldicarb, and its manufacturer, Bayer, has agreed stop using it. Eventually.

Registered in 1970 for use on cotton, according to the Wall Street Journal, the chemical has been used for years on potatoes, soybeans, peanuts, cotton, tobacco, citrus fruits, sugarcane and other crops, but the EPA now says aldicarb "no longer meets our rigorous food safety standards and may pose unacceptable dietary risks," especially to young children.

The agency's change of heart is based on a new study of the chemical, even though 25 years ago, as Scientific American points out, aldicarb sickened more than 2,000 people who ate California watermelons.

So now, the EPA says, Bayer has agreed to stop using aldicarb first on citrus fruits and potatoes, it will "voluntarily" phase out production by the end of 2014, and "all remaining aldicarb uses will end no later than August 2018."

The EPA will also revoke its rules on how much of the pesticide is allowed in foods, "to ensure we have the safest food supply possible." However, aldicarb "will continue to be registered for use on cotton, dry beans, peanuts, soybeans, sugar beets, and sweet potatoes."

So the pesticide poses health risks and shouldn't be allowed in food—but it will be for another few years. And no explanation for why the less-than-safest food supply possible has been acceptable up until now.

If this doesn't seem like support for the precautionary principle, I don't know what is. Instead of assuming things are safe until proven otherwise, and instead of actively working backwards, as the Environmental Working Group is concerned the EPA is currently doing on chemical safety for children, the lesson from aldicarb seems to be: if the science is out, use of the chemical should be, too.