The makers have 30 days to provide safety data to support claims that the caffeine use is generally recognized as safe.

CNN: FDA: Caffeinated alcoholic drinks may be illegal

Ingredients added to food are considered unsafe and against the law unless the FDA approves their use or unless the ingredients are "generally recognized as safe, " a designation that still requires evidence of safety at the levels used in the product.

CNN: FDA: Caffeinated alcoholic drinks may be illegal