Bon Chef has been dedicated to manufacturing and supplying the most durable products available to the food service industry. Bon Chef Pewter Glo (inserts) plates, platters, bowls, ramekins, mugs are hand crafted from aluminum alloys that are rated 100% food safe. Safe temperatures -20 degree F to a maximum temp of 650 degree F. Do not use pewter glo products for food storage. Ware washing: Use only metal safe detergents and sanitizers. For heavily soiled conditions, presoak in hot water. Do not scour or scrape. Use only nylon or sponge pads to clean. NSF certified.