A time temperature indicator (TTI) is a device or smart label that shows the accumulated time-temperature history of a product.
These small recorders are also used to identify the time (and thus location) of a shipment when the problem occurred, which allows for corrective action.
There are a large number of different time temperature indicators available in the market, based on different technologies.
Meals, Ready-to-Eat (MREs) from the US military have included "Fresh-Check" TTIs on the cardboard boxes since 1997 to help estimate their shelf lives.
[6] Surveys within the European Union projects "Freshlabel" and "Chill-on" have shown positive feedback from consumers on the use of TTIs on food products.