Officials in Michigan last week issued the state’s first-ever advisory for toxic PFAS chemicals in beef after finding elevated levels in cuts of meat from a local farm.

Beef from the Grostic Cattle Co. in Brighton, Michigan, contained an average of 1.9 parts per billion of Perfluorooctane sulfonic acid, also known as PFOS, one of the most common types of PFAS, short for per- and polyfluoroalkyl substances. Though the levels weren’t high enough to trigger a recall, state officials said long-term consumption of the meat could pose a public health risk and notified customers, including several local schools.

Michigan officials called the event a “rare occurrence,” but PFAS contamination has also shut down operations at dairy farms in New Mexico and Maine in recent years. The U.S. Environmental Protection Agency, or EPA, is working on a plan to regulate the chemicals after years of urging from scientists and environmental advocates, who say PFAS use remains widespread despite evidence of the chemicals’ negative health impacts.