Freeze Indicators

FREEZEmarker® is an easy-to-read freeze indicator that monitors exposure to freeze events and provides a visual signal when a freeze event occurs

Single-Use FREEZEmarker Freeze Indicator

FREEZEmarker is a single-use freeze indicator that provides an easy-to-read, irreversible visual signal when a freeze event at or below the response temperature occurs.

Freeze Indication

The green circle and white checkmark are visible in the indication window at temperatures above the response temperature. When exposed to temperatures at or below the response temperature, the green circle and white checkmark will turn partially or completely white (opaque/cloudy), showing that a temperature excursion has occurred and endpoint has been reached.FREEZEmarker freeze indicator

For example, when FREEZEmarker B has been exposed to temperatures at or below -2°C (-1oC response temperature with+/- 1oC accuracy), the green circle with white checkmark will partially or completely change to white opaque/cloudy, showing that a temperature freeze event has occurred.

If uncertain whether the end point has been reached, users can press the circle with their fingertips to evenly distribute the white particles.


FREEZEmarker is a self-adhesive label that can be applied directly to product surfaces or packaging.

FREEZEmarker Response Temperature Response Time Accuracy
L 0oC 30 minutes  +/- 1oC
B -1oC  30 minutes  +/- 1oC
C -6oC  30 minutes  +/- 2oC

Response time is the time below the lower temperature limit. The lower temperature limit is the response temperature minus the accuracy. For example, a FREEZEmarker L with  0°C response temperature and  ±1°C accuracy has a lower limit of tolerance of -1°C.


TransTracker is a card with a FREEZEmarker mounted on to it and can be placed in the packaging to monitor freeze events during shipping.  TransTracker cards come with detailed instructions for reading the indicator and may be customized with branding and messaging from the shipper or supplier.

TransTracker Response Temp Response Time
C  0oC
 30 minutes