Tamera's skin care line has all natural ingredients. It is best to keep all natural skin care products in a cool space, then they can last for years.
Light Polish may go rancid if kept in super warm conditions for a long period of time. Much like like oatmeal or cornmeal would become rancid in warm conditions in your cupboard for too long.
Light Creme and Earth's Essential Creams are made of natural oils without preservatives, therefore they are not suited for long term room temperature, outside of cool conditions.
We recommend our clients to keep them in their refrigerator. Storing creams in the refrigerator also adds/enhances the way it feels and works in the skin. If kept on the shelf at room temperature (or warmer, like in bathroom cabinets) it can spoil quickly like anything with oils. If stored in an air conditioned room or refrigerator, they will last much longer.