My daughter, my husband and my mom all had theirs catch fire. My theory is that if you only cook 1 small potato there is not enough moisture or steam to prevent the bag from burning. When I cook 2 or more potatoes my bag is very wet by the time they are done cooking. I never leave the bag cooking unattended out of fear of a fire. Potatoes taste so darn good cooked in them that I still want to use the bags!