Shrek drinking glasses

( Photo courtesy of Consumer Product Safety Commission )

When cadmium was discovered in the painted design on "Shrek"-themed drinking glasses that were sold nationwide at McDonald's, the burger giant recalled 12 million of the cheap U.S.-made collectibles while dramatically expanding contamination concerns about the toxic metal beyond imported children's jewelry.

The U.S. Consumer Product Safety Commission announced the voluntary recall on June 4, warned consumers to immediately stop using the glasses; McDonald's said it would post instructions on its website next week regarding refunds.

The 16-ounce glasses, being sold for about $2 each as part of a promotional campaign for the movie "Shrek Forever After," were available in four designs depicting the characters Shrek, Princess Fiona, Puss in Boots and Donkey.