Abstract: A method of safely storing containers containing chemical substances in accordance with a preconceived plan which comprises; examining each container to assure the integrity of each container containing such chemical substances and that said container is suitable for the storage of its contents for a predetermined period of time. If the container is deemed fit to store the contents, then, the exterior of the container is examined for exterior marks which will help to determine what the contents really are. Next a classification scheme for the said chemical substances is developed. This entails the establishment of a colour to be applied to the exterior surface of said container after a determination of the container's contents has been made. A corresponding number to be applied to the external surface of each container. The number of classes must next be determined for the plan (arbitrary).