The shell protects hard-boiled eggs and prevents them from spoilage that can cause serious foodborne illness. But even hard-boiled eggs properly stored in the refrigerator have a limited life. To keep track of the age of hard-boiled eggs, write the date lightly on just-boiled, cooled eggs before you put them in the refrigerator.

Hard-boiled eggs are safe in the refrigerator for up to one week. Dry the eggs with a paper towel, then store them in the carton because the porous shells may absorb odors from other foods. Don't store the eggs in the refrigerator door because the door is frequently opened and the temperature isn't stable. Never allow hard-boiled eggs to remain out of the refrigerator for more than two hours because bacteria develops rapidly at room temperature.