It’s one of the most refreshing alcoholic drinks out there: the Moscow Mule, traditionally served ice cold in a copper mug. But is that mug actually dangerous for you? It could be, but probably not.

The Iowa Alcoholic Beverages Division recently put out an advisory bulletin warning about the dangers of drinking from copper mugs, as generally copper shouldn’t come in direct contact with food or beverages because of concerns about humans consuming it.

But while high concentrations of copper are indeed dangerous, experts estimate that you’d have to drink from a copper cup every meal of every day for 25 years in order to be poisoned, according to a Business Insider report. And if you’re drinking that much per day, you’ve probably got bigger problems than copper poisoning.

So go ahead and drink from that copper mug. Just remember: everything in moderation.

“The purpose of this bulletin is to advise licensees and permittees selling and serving alcoholic beverages in copper mugs of the applicable federal guidance and state regulations regarding the use of copper and copper alloys in contact with food and beverages,” the advisory from Iowa reads. “The recent popularity of Moscow Mules, an alcoholic cocktail typically served in a copper mug, has led to inquiries regarding the safe use of copper mugs and this beverage. The use of copper and copper alloys as a food contact surface is limited in Iowa. Iowa, as well as many other states, has adopted the federal Food and Drug Administration’s Model Food Code, which prohibits copper from coming into direct contact with foods that have a pH below 6.0. Examples of foods with a pH below 6.0 include vinegar, fruit juice, or wine.”