Thanks to a special resin, these indicators show a colour change (to black) depending on temperature/time levels.
The indicator is affixed onto the blood bag during “validation” step, before placing it in the blood bank refrigerator (+4°C).
Assuming that the blood bag is not handle, the indicator will show the complete colour change at 45° day (natural shelf life of the bag).
Hemocontrol has a specific “data storage” to track temperature issues, peaks, anomalies in order to verify the correct blood bags’ handling and storage processes.