Cookware made from cast iron has been used for centuries, often passing down from generation to generation. Because it is prone to rusting, however, some cooks may understandably question its safety.
Cast-iron is not only safe to cook on, according to the Clemson University Cooperative Extension, it is relatively inexpensive, strong, adds iron to food and serves as an even heat conductor. Because it can rust, safe use of this crockery is dependent on proper care. This includes never using scouring pads or washing cast iron with strong or abrasive detergents.
For best results and rust protection, cast-iron cookware should be seasoned by heating unsalted cooking oil--preferably peanut oil--to a high temperature in the cookware, then wiping it out. Place greased cookware in a 350-degree Fahrenheit oven for at least an hour. For daily care, the inside of cast-iron cookware should be rinsed after using, wiped thoroughly dry and wiped down with a thin layer of unsalted oil.
Heating oil in cast-iron pots and pans fills cooking surface pores with carbonized oil, which helps prevent rusting and pitting, according to Your Cookware. This also creates a semi non-stick cooking surface.