If you’re going out with friends on a Friday night, it isn’t uncommon for some people to order a Moscow Mule.
However, an advisory bulletin is warning bars and restaurants against serving the drinks in a traditional copper cup.
The Food and Drug Administration prohibits copper from coming into direct contact with acidic foods with a pH below 6.0.
“High concentrations of copper are poisonous and have caused foodborne illness,” an advisory bulletin from Iowa’s Alcoholic Beverages Division. ” When copper and copper alloy surfaces contact acidic foods, copper may be leached into the food.”
Over time, Business Insider says that copper exposure can damage the liver and kidneys. Copper poisoning can cause people to experience nausea, vomiting, abdominal pain and liver failure. However, officials say it would take years of drinking Moscow Mules to develop issues from the copper.
If the copper mug is lined with another metal, it is safe.