Iowa health officials have warned that the copper mugs typically used to serve Moscow Mule cocktails may cause copper poisoning. The state’s Alcoholic Beverage Division warns that according to U.S. Food and Drug Administration guidelines, copper should not come into contact with acidic foods with a pH below 6, and a traditional Moscow Mule is “well below” that, according to the agency. When copper or copper alloys come into contact with acidic foods, the metal can leach into the food; the agency recommends using copper containers lined with a different “nonreactive” material, such as nickel, stainless steel, enamel or ceramic. See The Washington Post, August 8, 2017.