ColdMark Freeze Indicators put you in control even after your product has been shipped.  With ColdMark your customer will know at a glance if the product has been exposed to damaging or extreme temperatures during shipping or storage.  The ColdMark Indicator accurately shows if your product has been exposed to cold below 32°F (0°C).  This is done by its colorless indicator bulb turning to an irreversible violet color as temperatures rise above the Indicator's response temperature.  (Other response temperatures also available.)

More importantly, ColdMark is guaranteed to work within plus or minus 1° of this response temperature, the highest level of accuracy in the industry.  ColdMark Freeze Indicators are a strategic, value-added plus for your product, providing a permanent record that assures your customers of consistent quality.

When the Indicator is exposed to a temperature at or below the response temperature for approximately 30 minutes, the colorless bulb fluid solidifies and contracts.  This draws the colored liquids into the bulb and the bulb changes from clear and colorless to cloudy with streaks of violet.  When the Indicator is warmed to above the response temperature again, the bulb changes irreversibly to a uniform violet.