Ready Hour Salt lasts up to 20 years unopened, and one year once it is open. Store it in a cool, dry location where temperatures stay between 55 and 75 degrees for optimal longevity. There is no better container for your food. It is made of durable steel, it is waterproof, rodent-proof, and stores easily on a shelf or in a closet. Unopened, it can even float. Weighs 4.2 pounds.