What kind of shelf-life does calcium carbide have?
How long carbide will last in storage is dependant on what kind of container you keep it in and where you keep it. Calcium carbide reacts to moisture and that includes moisture in the air. If you live in a humid environment and keep your carbide in a can or tin that allows the air to get in, then it will begin to degrade. If you vacuum seal your carbide, you can expect it to last virtually forever.