Clark's Cast Iron Oil uses highly refined coconut oil to season traditional cast iron and carbon steel cookware. There are no synthetic chemicals added at all. Unlike flaxseed, grapeseed, canola, or palm oil, Clark's Cast Iron Oil will never go rancid and does not need to be refrigerated. It is very important to maintain the seasoning of your cast iron and seasoned steel cookware by applying a very thin layer of oil after each cleaning. This will help keep you cooking for decades. Pairs well with Clark's Cast Iron Soap.