The frozen shrimp were imported from Indonesian company Pt. Bahari Makmur Sejati and sold at Walmart stores as Great Value brand frozen raw shrimp.

The crustaceans in question made it to stores in 13 states before a full recall was implemented. While there isn’t any evidence that customers purchased the unsafe food, the FDA advised Walmart and recent customers to discard any BMS Food products.

Some packages of Great Value frozen shrimp sold at Walmart are at risk for potential for Cesium-137 contamination, the FDA says.