Steel All Iittala steel cookware is made of 18/ 10 stainless steel, that is 18 % chromium and 10 % nickel. Chromium protects the steel against corrosion. The addition of nickel to the alloy increases its corrosion resistance while adding a bright polished appearance, hardness, and exceptional resistance to all temperatures. Iittala steel dishes are easy to take care of, dishwasher safe, and look good for a long time. Before using a new dish for the first time, wash it in mild detergent and remove all stickers and labels.