What is the shelf life/stability of methanol?
Without interference from or interaction with external contaminants, methanol will not deteriorate or decompose, thus the shelf life would be indefinite. Problems arise if the product is not protected from exposure to contamination, including exposure to the atmosphere. For example, methanol is very hygroscopic, i.e., it readily absorbs moisture. So if the product is open to the atmosphere, it will absorb moisture directly from the air. Also, methanol is an excellent solvent, so it is very important that it be stored in a container of an appropriate material. For example, methanol will dissolve plasticizers in some plastics. Properly sealed and protected methanol should maintain its integrity for a very long time.
