McDonald's recalled about 12 million Shrek-themed drinking glasses on Friday after they were found to contain the toxic metal cadmium.
The 16-ounce glasses have a painted design from the new movie "Shrek Forever After" and were a part of a promotional campaign for the film, which premiered May 21.
According to the U.S. Consumer Product Safety Commission, the paint used in the design on the glasses contains cadmium, a carcinogen that has been found to cause weak bones and severe kidney problems.
"A very small amount of cadmium can come to the surface of the glass, and in order to be as protective as possible of children, (the Consumer Product Safety Commission) and McDonald's worked together on this recall," CPSC spokesman Scott Wolfson said.
The CPSC is concerned that children using the glasses may not wash their hands after use. The government agency also says long-term exposure to the paint could cause it to leech into the body.
"We believe the Shrek glassware is safe for consumer use," McDonald's USA spokesman Bill Whitman said. "However, again to ensure that our customers receive safe products from us, we made the decision to stop selling them and voluntarily recall these products effective immediately."