The U.S. Food and Drug Administration (FDA) has issued the results of a study finding that dark chocolate products may contain milk that is not declared on other labels. According to a February 11, 2015, consumer update, the agency tested dark chocolate bars for the presence of milk after dividing them into categories based on their labeling: (i) those that included precautionary statements such as “may contain milk” or “may contain traces of milk”; (ii) those labeled “dairy-free” or “allergen-free”; (iii) those that made no mention of milk on the label; and (iv) those with inconsistent labels—for example, a “vegan” product with a label indicating the possible presence of milk traces.

The results evidently identified milk in (i) two of the 17 dark chocolates labeled “dairy-free” or “allergen-free”; (ii) 55 of the 93 products that gave no clear indication of the presence of milk in the products; and (iii) all seven bars that declared the presence of milk. In addition, FDA reported, six of the 11 products disclosing “traces of milk” contained milk “at detectable levels high enough to potentially cause severe reactions in some individuals.”

“First of all, milk-allergic consumers should be aware that a high proportion of the dark chocolates we tested contained milk, even when the label failed to list milk as an ingredient,” said FDA researcher Binaifer Bedford. “And because consumers can’t be sure that a statement about milk is completely accurate, they may want to contact the manufacturer to find out how it controls for allergens such as milk during production.”