I worked in the restaurant called Sea Salt and we had more then 80 different salts, i knew something about my favorites.This is as it looks to me the Himalayan salt(supposed to be one of the healthiest salts on earth because it is kept under the remains of cold lava and it is not exposed to any pollutions of the air and etc.I suppose if you take it out it is exposed to the pollutions of the air and make sanse to me that is having exparation date :D I am not an expert but this is my conclusion on the humble knownlegde i have about it . Maybe samone can correct me ... But it is kind a funny post :D