The US Food and Drug Administration on Tuesday urged the public not to eat certain bags of frozen raw shrimp sold at Walmart, citing concerns about unsanitary conditions and radioactive contamination found in shipments from the same supplier.

Walmart announced a recall on Tuesday for Great Value raw frozen shrimp products after the U.S. Food and Drug Administration detected a radioactive chemical that may pose a safety concern. The FDA detected Cesium-137, a radioactive isotope of Cesium, on a single shipment of frozen shrimp imported from Indonesian company PT. Bahari Makmur Sejati.

The FDA says to throw away certain Great Value frozen shrimp sold at Walmart in Louisiana and 12 other states. Here’s what you need to know.