A device for monitoring the expiration of goods includes a substrate and
an unreacted composition affixed thereto which is intrinsically reactive
to one or both of its thermal environment and the length of time
following activation. The reactivity results in a color formation of the
composition with the color formation being a single color upon reaction
to one of said thermal environment or length of time and multiple colors
upon reaction to both. The device may be a label affixed to a container
containing the goods to be monitored or may be printed directly on a
container.