Putting on your face can be dangerous—and not just if you’re driving. Mercury, also known as thimerosal, has lately held the spotlight as one of cosmetics’ problem children because of its association with neurological damage. Earlier this year, Minnesota took the progressive step of banning intentionally added mercury (as opposed to microscopic amounts that may not be detectable) from mascara, eyeliners, and skin-lightening creams—the first state to do so. “Mercury is one of the most deadly toxins, and we’re trying to reduce the amount of mercury that’s in the environment,” says Senator John Marty, who sponsored the ban. Minnesota retailers could be fined as much as $700 for knowingly selling cosmetics that contain mercury, and Minnesota manufacturers that fail to disclose the presence of mercury on product labels could be penalized up to $10,000.
Most cosmetic companies have stopped using mercury, but some still add it to mascara because it acts as a preservative and germ killer. Mercury doesn’t cause immediate damage, but frequent, long-term exposure can cause neurological problems in adults and impact babies’ brain development in utero.