| abstract |
An adjustable accumulated thermal exposure indicator device, and method of use, for affixing to and indicating deterioration of perishable goods and the like, comprising (1) a reactant yielding material that reacts via one or more steps at a rate depending on time, temperature, and pH to provide an amine and (2) an indicator that reacts at a time, temperature, concentration and pH dependent rate with the amine to produce a visible reaction that is indicative of the expiration of a predetermined time-temperature history related to the useful life of the goods to which the device is affixed. Also provided is a device or article that is responsive to accumulated thermal exposure for the controlled release of immobilized alcohols and amines. |