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Background. As perishable producers know, each perishable (for example, chilled & minimally processed foods, beer, vaccines, pharmaceuticals, blood, flowers, film, chemicals, adhesives and many other products) has a unique shelf life which depends on the packaged product’s initial microbial load (if a food, the gas composition; if CAP/MAP, time-temperature history, moisture loss, etc.). Both quality & safety are affected by these physical, chemical or biological factors (often inter-related). However, temperature is the predominant factor in determining how long acceptable quality lasts for a given distribution including storage at home and when it might disappoint its user or consumer. The management of perishable products is never perfect—resulting in variations in temperature during the cold chain, specifically in the loading, unloading, transport and storage of products through distribution. When temperature spikes occur, left unanswered is how much of the shelf life of a perishable was lost due to these spikes—leaving resolution of invoice disputes to accounting, insurance claims and customer service personnel.

BASIC ASSUMPTIONS Freshtime™ tags supplement a perishable’s “best-if-used-by”, “expiration” or “beyond-use” date. Each perishable product has a unique spoilage rate (shelf life). Perishable producers know this spoilage rate and use it to determine the expiration date. Most commonly, a spoilage rate is based upon the principle that a perishable’s microbiological and biochemical deterioration follows the Arrhenius equation which varies in response to temperature. Shelf life is determined by the integration of the Arrhenius equation—the output of which is a quantitative product-specific shelf life which correlates to the temperatures the product has been exposed to over its lifetime with a single visual result. Freshtime™ SHELF LIFE Supports a spoilage rate that is linear, exponential or other. Supports a perishable which spoils differently while frozen than when refrigerated. Takes the perishable producer’s shelf life data, senses temperature and then accessing the tag’s data tables determines shelf life “used” and “left” for the sensing interval.