Copper cocktail mugs can be poisonous, health officials say

Copper mugs commonly used to serve Moscow Mule cocktails can potentially poison drinkers, according to the Iowa Alcoholic Beverages Division.

The body examined the relationship between copper and food, and concluded that serving any food or liquid with a pH balance below 6, including vinegar and fruit juice, could result in copper poisoning – which can cause diarrhea, vomiting, jaundice and low blood pressure.

A statement from the division reads: “The pH of a traditional Moscow Mule is well below 6.0. This means that copper mugs that have a copper interior may not be used with this beverage.

“However, copper mugs lined on the interior with another metal, such as nickel or stainless steel, are allowed to be used and are widely available.

“High concentrations of copper are poisonous and have caused foodborne illness. When copper and copper alloy surfaces contact acidic foods, copper may be leached into the food.”

The division notes that copper mugs lined with another metal such as nickel or stainless steel “are allowed to be used and are widely available”.