After Opening Labels - Color Changing Food Freshness Indicator Monitoring Time & Temperature for Modified Atmosphere Packaging (MAP) Products

High-tech & Low cost, Visual indicators of Time and Temperature for various application in Food Industry for Fresh Produce, Meat Products, Retail, FMCG etc.

Fully automated timer for modified atmosphere packaging (MAP) products

The label is pre-applied to the inside of the packaging so that it is visible through the transparent lidding or packaging material. The label is activated by CO2 and so is suitable for modified atmosphere products where gas flushing is used in the packaging process.

How it works

When the consumer opens the pack the CO2 level decreases due to the modified atmosphere within the pack being displaced by air. This change in CO2 concentration causes the label to begin to change colour. The labels are calibrated to change colour over different time periods for different foods, with the colour wheel allowing the consumer to know if the product is fresh or not.

The label is suitable for any product which is packaged under a modified atmosphere and which has a short recommended shelf life after opening.

The label is both time and temperature sensitive. This means that if the product is stored above its recommended temperature once the pack has been opened, the label will change colour quicker than it would have done at the recommended refrigerated temperatures.


By giving consumers a visual indication of how long a food package has been open, it allows them to make an informed decision to use the food before it is no longer fresh to eat, thereby helping to reduce unnecessary food waste.

Typical products

  • • Sliced Meats
  • • Block/Sliced/Grated Cheese
  • • Pitta Breads
  • • Part Baked Breads
  • • Bagged Salad

Critical success factors

Each product has been designed to work at a particular CO2 level and temperature range. For the product to work correctly the storage temperature, type of timer and the CO2 level within the modified atmosphere need to be verified.
The lidding or packaging material must also have a transparent area in order for the label to be visible.

Product composition

The labels consist of a clear polypropylene film, a pigmented/coloured polyethylene film, and a white polyester barrier film.

Food Contact Approval

The polyester barrier film acts as a functional barrier (proven and tested by Smithers Pira). As a result, the labels are in compliance with Regulation (EC) No. 1935/2004 and Regulation (EC) No. 10/2011, allowing use with all classes of foodstuffs for:

(a) up to 30 days at temperatures up to 40°C

(b) all storage times at refrigerated and frozen conditions including heating up to 70°C for up to 2hours or heating up to 100°C for up to 15 minutes.

Application of label

The label is fixed to the inside of the film or packaging material. This can either be applied online using a standard label applicator, or can be pre-applied to lidding or film
The design can be tailored to the requirements and preferences of customers. Please note that the reference colours are yellow to blue or yellow to purple. The label can incorporate the design or the design can be pre-printed on the film with a central window left clear, and the film applied to the underside of this window


There are no special storage or handling requirements for these labels, however, due to the nature of this product we would recommend that they are used within a six month period and are stored in a cool, dry environment away from direct sunlight.


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