Timestrip Temperature Indicators for Food

Timestrip Food temperature indicators, for food temperature monitoring, make tracking temperature breaches across a multitude of cold chain food industry applications a simple, cost-effective process.

Timestrip Temperature Indicators for Food temperature monitoring, makes tracking temperature breaches across a multitude of cold chain food industry applications a simple, cost-effective process. T

Food is a Timestrip® temperature indicator that shows how long your product has been above the threshold temperature.
Inert until activated and self-adhesive, it can be stored at room-temperature then stuck to a product or package when needed.

It is single use and the indication is irreversible. It is splashproof and there is an expiry date on each pack shipped.

Use Timestrip® Food temperature indicators to monitor the time that potentially hazardous food has been exposed to temperatures between 5°C and 60°C where food poisoning bacteria can grow rapidly in this range to unsafe levels.

Use Timestrip® Food temperature indicators for ready to eat potentially hazardous food
As a general rule, the total time that a ready to eat potentially hazardous food can be kept at temperatures between 5°C and 60°C is 4 hours. After this time the food needs to be discarded.

Use Timestrip® Food temperature indicators to monitor the 2-hour/4-hour rule for ready to eat potentially hazardous food brought out of refrigeration
The 2-hour/4-hour rule is a rule of thumb that has been designed to help businesses deal with some of the practicalities of handling refrigerated ready-to-eat potentially hazardous food.
It recognises there may be several circumstances where this type of food is brought out of refrigeration and held at temperatures above 5°C for convenience; for example, while preparing food at a kitchen bench or displaying food for service for short periods.
The rule provides options for what can be safely done with ready-to-eat potentially hazardous food brought out of refrigeration, depending on how long it has been at temperatures above 5°C.

If the total time is:

  • less than 2 hours, the food may be used or refrigerated for later use
  • between 2 and 4 hours, the food may still be used
  • 4 hours or longer, the food needs to be thrown out
Timestrip how it works food indicator


  • Reduced Oxygen Packaging
  • Fresh Seafood
  • Fresh Produce
  • Airling Catering
  • School Meals
  • Home Delivery Diets
  • Food Retailing
  • Restaurants
  • Hub and Spoke Production

Products Available

Timestrip Food 5ºC/41ºF
2 – 4 hour run-out window

timestrip food temp indicator8C

Timestrip Food 8ºC/46ºF
2 – 4 hour run-out window

timestrip food temp indicator 10C

Timestrip Food 10ºC/50ºF
2 – 4 hour run-out window



Irreversible, single use
35mm x 19mm
Activation Feature
A manual activation button on the top – the ‘ON’ window turns blue to confirm it is armed.
Breach Indication
Visual display
Temperature Accuracy
+/-1°C / 2°F
Time Accuracy
+/-15% in isothermal conditions
Recommended Storage
Room temperature: 22°C/72°F at 20-80% humidity. Cool dark environment.
100 indicators per bag. Labelled with expiry and batch number.
Shipping Package Requirements
No special requirements as inert until activated.
Splash proof
Shelf life
Pre-activation: 2 years from shipping for most lines, otherwise 2 years from manufacturing date. Active life: up to 1 year.


What is Timestrip® PLUS?

It is a single use temperature indicator in a self-adhesive label format. It indicates if the temperature has risen to breach a defined threshold and it records the cumulative elapsed time of all such breaches. Each product in the range is engineered to respond to a different threshold temperature so customers can choose the product that best suits their needs.

How can I use Timestrip® PLUS?

They are suitable for many situations when elevated temperatures can create problems for a product. Common applications are frozen or chilled foods, medicines, vaccines, adhesives and chemicals. A common use is to identify the elapsed time of temperature abuse during shipping. Another is for products which are taken repeatedly in and out of their ideal storage conditions for temporary use, like lab chemicals. One or two excursions might not be problematic, but Timestrip® PLUS shows the cumulative time of all excursions and this can be used to trigger a timely replacement of the product.

How does Timestrip® PLUS work?

A blue dye housed in a blister is held adjacent to a micro-porous membrane. Upon squeezing the activation button the liquid dye comes out of the blister and into contact with the membrane. If the temperature of the product is below the stated ‘STOP’ temperature, the blue dye changes state to solid form, and it is unable to move through the membrane. If the temperature rises to or above the threshold temperature, the dye changes to liquid form and moves at a precise rate through the membrane. Its progress is irreversible and the distance it travels through the viewing window indicates the cumulative time the indicator has been exposed to the threshold temperature or above.  Once activated, Timestrip® PLUS will keep monitoring temperature for days, weeks or months, depending on your needs. During that time it will record how long any temperature breaches last. Here is an example. An 8°C Timestrip® PLUS was chosen to monitor a shipment which would take 3 weeks to arrive. When the shipment arrived, the indicator showed 4 hours of 8°C breach. This breach could have happened in one long event or from a series of shorter breach events across the 3 weeks. The 8°C Timestrip® PLUS could have indicated up to 8 hours of temperature breaches during that 3 weeks.

Are Timestrip Plus indicators waterproof?

Timestrips® are not designed to be submerged in water, but they are very splash-proof and can be immersed in water for short periods without any effect.

Is the liquid safe?

Yes.  We only use food-grade oils and non-toxic colourants in our formulation. In the unlikely event that the liquid leaks from the indicator and comes into contact with skin, simply wash with soap and water. If the liquid comes into contact with eyes, rinse immediately with plenty of water and seek medical advice. The MSDS is available for further information.

Can Timestrips be used in any direction / orientation?

Yes.  Orientation has no impact on the way it works.

How are Timestrip® PLUS products evaluated for their time accuracy?

Timestrip®  PLUS are polymeric multi-layer indicators. They are based on spontaneous lateral wetting by a blue liquid inside a porous substrate and not a chemical reaction. Each production batch (7000 – 8000 products) undergoes strict quality control tests to validate its time accuracy. This is conducted via a computer vision software (TSCV) which analyses scanned photos of seven randomly-selected products from each batch (roughly 0.1% of the population). The photos are taken at different elapsed times and the tested products are placed at their designated temperature through the entire test period. The software automatically analyses the lateral progress and the elapsed time of each product tested and the data is presented numerically and graphically in a specific file which is labelled by batch.  This data is translated into a final release report which is attached to the outgoing product batches.  

What happens at elevated temperatures?

Due to the nature of liquids, higher temperatures reduce the viscosity of the liquid dye in Timestrip® PLUS. The correlated result is faster/shorter run-times (the progressing blue dye will reach each printed time-mark sooner than intended). So, if an 8°C/46°F indicator is exposed to 25°C/77°F for a consistent period then the blue dye will progress more quickly through the membrane than if it was exposed to 10°C/50°F for a consistent period. This graph shows the run-time acceleration of a 10°C/50°F Timestrip PLUS at different elevated temperatures. The y-axis represents the actual run-time of the liquid dye at different temperatures and is expressed as a percentage of the specified run-out time at an isotherm of 12°C/54°F. So, at an isothermal temperature of 12°C, the liquid dye will reach each time-marker (1, 2, 4, 8, hours etc) within these times +/-15% in time. However, if for example the product is exposed to an isotherm of 21°C/70°F the dye will reach each time marker within only 77% of the intended run-time. In other words, it will reach the;
• 1 hour time-marker within approximately 46 minutes (77% of 1 hour)
• 2 hour time-marker within approximately 1.32 hours and so on.
At a less extreme temperature elevation, say 15°C/59°F the blue dye will reach each time-marker at 91% of the intended time.

Why is there an activation window and a runout window?

The activation window gives confidence that the product is armed. The breach/run-out window is separate so that it clearly indicates a breach of the temperature threshold and the cumulative elapsed time of the breach.

What is the maximum run-time Timestrip® PLUS range can offer?

The maximum run-time varies between hours to days dependent on the product and its application. Note that the run-time is only referring to the time above its breach temperature.  Timestrip® PLUS can remain active and vigilant for long periods of time (up to a year after activated) if the run out window has not completely filled in.

What is the accuracy of the hour marks?

Every Timestrip Plus™ product is calibrated to a temperature of 2˚C above its stated threshold temperature. For example, Timestrip Plus™ 12˚C is calibrated to a temperature of 14˚C. When the product breaches its threshold temperature and is held at a constant temperature(i.e. isotherm) of 14˚ C, it will reach the 1 Hour print mark within 1 Hr (+/- 15% in time) intended time.

Timestrip® PLUS compare with data loggers?

There are fundamental differences. Data loggers are expensive and typically are designed to go on large shipments. They are not an immediate tool as they need to be returned/connected for the data to be read and acted on, and they have to be used repeatedly to justify the expense. They also require power. Timestrip® PLUS indicators are less expensive, require no power, are single use and can be instantly read by the end user. They have unique serial numbers to ensure the traceability of each indicator to avoid the potential for manipulation across the distribution chain. As well as being effective for large shipments, Timestrip® PLUS are small light and cost effective enough to be used at the carton or single unit level. Using them at multiple points within a shipment or container can isolate unacceptable temperature pockets. Data loggers provide a full history of temperature from the time of activation. Timestrip® PLUS records how long a product has been above its threshold temperature (up to the maximum printed on the scale – usually 8 or 12 cumulative hours) but cannot tell you when the breach or breaches occurred. Timestrip® PLUS is most often used to monitor and validate the “last-mile” of a cold chain or another temperature environment, in other words, when the product is close to its eventual use. In some cases data loggers and Timestrip® PLUS indicators may be used in complementary ways to help monitor temperatures.

Can you customise for us?

We have a growing range of standard products that meet most cold chain requirements. As a general rule, if you require more than 50,000 units, we can customize the print, and in many cases, even the melt temperature, although we have an extensive existing range. There is a premium for this service. We can also quote on custom carrier cards and backing labels, if you need to provide instructions, add other languages, or a form to provide a permanent record.

What can they be used on?

Anything where elevated temperatures are an issue. Common applications are frozen or chilled foods, medicines, vaccines, blood products and adhesives.

How accurate are Timestrip® PLUS?

+/- 1 ̊C for the temperature component and 15% for the time component under isothermal conditions. The progress of the blue dye across the time-markers is calibrated to a temperature of 2 ̊C above the stated threshold temperature. For example, the time markers for Timestrip® PLUS 12 ̊C are calibrated to a temperature of 14 ̊C. When the product breaches its threshold temperature and is held at a constant temperature of 14 ̊C (i.e. isotherm), the blue liquid will reach the 1 hour print mark within 1 hour (+/- 15% in time). If the breach is at a much higher temperature than the stated threshold temperature, the indicator dye becomes thinner and will run faster.

Can Timestrip Plus indicate if a temperature has fallen below a certain point?

Timestrip Plus™ can only show ascending temperature excursions. We have other products that do this type of descending temperature indication.

What is the shelf-life of Timestrip® PLUS?

Most Timestrip® PLUS products are provided with a shelf life of 2 years from shipping from our premises. Some formulations may be provided with a shelf-life of 2 years from the date of manufacture. In all cases, an expiry date is provided for each batch of products supplied.

Any special storage requirements before activation?

No, unlike some other threshold temperature products, Timestrip® PLUS can be stored inert at ambient temperatures and only activated when needed.

Do I need to pre-condition indicators prior to activation?

No. Unlike some other threshold temperature products, Timestrip® PLUS does not require pre-conditioning. You need to activate above the product’s threshold temperature, as you cannot squeeze the dye out of the blister if it is in solid form. Immediately after activation, stop the progress of the dye by placing the indicator below its STOP temperature. You can adhere the Timestrip immediately to a product or carrying card which is below the STOP temperature. Alternatively, place the activated indicator in an environment much colder than the STOP temperature for a short period of time.

Why do Timestrip® PLUS have a ‘START’ and a ‘STOP’ threshold temperature?

The melting point of a solid is the temperature at which it changes state from solid to liquid. The freezing point (or crystallization point) is the temperature at which a liquid changes to a solid. For certain substances, the melting and freezing point are not the same and the freezing point is lower than the melting point. This behaviour is called hysteresis. At the STOP point (freezing point) the dye can’t move. At the melting point, the dye moves and indicates a threshold breach.

Why does Timestrip give away 1 or 2 free products with every pack of 100?

Because we like our customers!

You can use these free products for testing, training, validation or just to save money. In the unlikely case any got damaged along the way or someone just wanted to try one, there is no need to get in touch, although we’re always happy to hear from our customers.

Personally, we think that all companies should give stuff away for free!

Can I get a false positive indication

If the indicator is correctly activated false positives are extremely unlikely as the blue dye can only melt at or above certain temperatures.  It is important to lower the indicator to its STOP temperature after activation and only attach it to a product, carrying card or material that is already at or below the STOP temperature to avoid premature indication.

What if one of the indicators in my pack has got a blue activation window or there is blue in the run-out window, before I’ve pressed the activation button?

If stored under the correct conditions, there is very little risk of auto-activation, but occasionally, this can happen, and the built-in activation window lets you know it. If an indicator has auto-activated before use the activation window will already be showing blue and ON. The blue liquid may also be showing against the time-markers in the run-out window. If this happens, discard the indicator and select another. There is no need to contact us, as we ship a few extra units per hundred anyway.

Can I customise the temperature threshold if you don’t make one that I need?

We have a wide range, but if none of our products suit your needs we can investigate a new threshold temperature. There is a cost for this development service and not all temperatures are possible. Please contact us for more information.

What are your Acceptable Quality Limits (AQL’s)?

The Accepted Failure Rate is based on ANSI/ASQC Z1.4 (formally MIL-STD-105E) Level II Normal Inspection. Packs are over shipped by 2-3 units per 100 to cover this AQL.

Central to this process are tests against defined specifications for; how quickly the dye progresses through the membrane, environment sensitivity (high heat and vacuum tests to check resilience to harsh conditions during shipping) and also the accuracy of the threshold melting point. A full pack of release reports is provided with each shipment. Further details are available on request.


Timestrip Food Brochure
Timestrip Food 5ºC/41ºF User Manual
Timestrip Food 8ºC/46ºF User Manual
Timestrip Food 10ºC/50ºF User Manual

Contact us
today if you require an MSDS or Testing Protocol