Cold Chain Package Testing

Cold Chain package testing is used to test the ability of the package system to protect temperature sensitive products as they move through the supply chain. Cold Chain package testing can help ensure that perishable items such as food, perishables, and medical products remain within the desired temperature range during transportation.


Most people probably don’t even really think about the Cold Chain much less Cold Chain package testing. Cold Chain refers to getting a variety of products like, fruit, vegetables, meat, medicine, wine, and even ice cream through the temperature extremes of our daily environment. These products need to be preserved from the point of manufacture to the consumer and require either refrigerated or frozen conditions.

Cold Chain can be divided into active and passive systems. Active systems have the most control over conditions since they use a refrigeration system. Think of a refrigerated trailer filled with produce using an external refrigeration system that requires fuel. There are also battery operated refrigeration systems that are easier to transport and do not require fuel to operate.

Passive Cold Chain packaging consists of gel packs or dry ice as common refrigerants and the use of an insulated shipper, like an expanded polystyrene cooler. The Pandemic has launched a whole new focus on Cold Chain packaging as companies providing meal kit subscriptions have blossomed. These Cold Chain package systems need to be tested in order to ensure the efficacy and safety of the product. Cold Chain packaging can be referred to as thermal packaging or Thermal Shipping System.

What Is Cold Chain Testing?

There are two distinct parts to Cold Chain package testing. Thermal performance qualification is the ability of the package system to maintain the required conditions. Just as important is testing the Cold Chain package through a simulated distribution test. The results of both tests are vastly different, but will provide a full picture of what to expect from the Cold Chain package.

Thermal performance qualification evaluates the effectiveness of a thermal package to provide the necessary conditions over a defined period. The core design of a Cold Chain package system consists of insulation and a refrigerant. The combination of these two components will determine the effectiveness of the packaging. Certain products, such as food, chemicals, and medicine must be kept at specific temperatures as they travel from the distributor to the consumer. Refrigerated conditions are typically +2°C to +8°C (+35.6°F to +46.4°F) and are difficult to maintain due to the narrow temperature range. Frozen conditions, 0°C (+32°F) and below, are typically easier to maintain. Thermal performance qualification quantifies the ability
of the Cold Chain package design to maintain the required temperature range.

Once the Cold Chain package has passed the thermal performance qualification, the next step is the distribution test. A distribution test is selected and may consist of ISTA 3A, ASTM D4169, or some other defined test sequence. A distribution test is comprised of a test sequence to include distribution hazards such as impacts, compression, and vehicle vibration. Upon test completion the Cold Chain package is opened and evaluated based on the condition of the contents.

Importance Of Cold Chain Testing

When it comes to transporting temperature-sensitive products, there’s not much room for error. Any excursion outside the required temperature range has the potential to damage or even destroy temperature-sensitive products. A shipment of food can easily spoil without the proper protection. Medicine that hasn’t been kept at the proper temperature can pose a serious health risk to consumers.

Common carriers like FedEx and UPS have invested heavily in the equipment and infrastructure necessary to transport temperature-sensitive products worldwide. Even with all this infrastructure, successful delivery starts with the package. Whether the product is a pallet load of cut flowers or a single shipper containing vaccines the manufacturer needs to test the packaging. Cold Chain testing allows manufacturers to qualify their cold chain package systems to meet their requirements. Westpak has the tools and expertise needed for a thorough assessment of the thermal and physical characteristics of all cold chain packaging and components.

Frequently Asked Questions

Get answers to our most frequently asked questions.

What's involved with cold chain package testing?

In general, a Cold Chain package is a passive system requiring an insulated material and refrigerant in the form of a gel “brick” or dry ice. Several variables need to be considered in a passive system prior to conducting a Cold Chain package test. One of the most important variables is the thermal mass of the product. Thermal mass is defined as the ability of a product to store heat and is calculated by multiplying the heat capacity by the density of the material. Of course, we do not need the actual thermal mass, but it does answer the question about “how much?” are we are going to ship. There is a big difference in thermal mass if we are shipping ice cream or vials of medicine.

The most significant components of a Cold Chain package are primarily the shipper, typically a premade insulation layer providing thermal resistance, and the refrigerant, usually gel packs of water or saline, or dry ice. Therefore, defining the requirements before conducting any cold chain testing is essential. The following is a list of other variables to be considered.

  • Required product temperature range
  • Thermal mass of product
  • Shipper thickness or density
  • Amount of refrigerant
  • Duration in transit
  • Temperature profile to be used for qualification

Once the above variables are defined, the next step is to develop acceptance criteria for the Cold Chain package. The acceptance criteria are how you will know whether the package meets your requirements. Acceptance criteria can be as simple as “The package must maintain a temperature range of XX degrees for a duration of XX hours.” Now qualification of the Cold Chain package can begin and involves:

  • Instrumenting the product with thermocouples
  • Assembling the package
  • Subjecting the package to a temperature profile

However, there needs to be agreement about what temperature profile to use. A temperature profile that is too mild or too extreme can make or break a Cold Chain package. Using a temperature profile based on actual data defined in published standards is the most effective way to qualify Cold Chain packaging.

What is the temperature of the “cold chain”?

The appropriate temperature for cold chain transportation will depend on the type of product being transported. Typically, these fall into two categories; refrigerated and frozen. Refrigerated is defined as +2°C to +8°C (+35.6°F to +46.4°F) and is often difficult to stay within this range. Knowing the temperature range of the product can help in the successful delivery and function of the product. The acceptable temperature limits of the product may be higher than +8°C and can be used in defining the acceptance criteria for the qualification. Frozen conditions usually do not vary that much since dry ice is typically used to meet these requirements. Dry ice sublimes (turns from a solid to gas) at -78.5°C (-109.3°F) and was ideal to transport COVID vaccine.

What types of products benefit from cold chain testing?

Any temperature sensitive product that must be transported within a specific temperature range using a Cold Chain package. It is important to know whether the package is maintaining the required condition. Cold Chain package testing is conducted to verify that the temperature can be maintained throughout a normal distribution cycle. Having Cold Chain package performance data can also help with make a decision about the product should a package get stuck during distribution.

Why is it important to maintain a cold chain system?

Cold Chain packaging is just one part of the Cold Chain system. Today, the distribution environment may include Third Party Logistics (3PL) companies with tracking systems and the ability to “refresh” a package if necessary. Having these services available ensures the success of the Cold Chain package in the event of an unforeseen delay. These support systems have become more critical due to the current interruptions in the supply chain.

Which test standards are associated with cold chain package testing?

The following test standards are associated with Cold Chain package testing and include both package qualification and distribution testing.

The team at Westpak is experienced and capable of conducting Cold Chain testing and interpreting the results. Contact us today to learn more about how we can help you facilitate a successful shipping operation.


Testing at Westpak has been accredited by A2LA to comply with ISO 17025.

Westpak testing labs are ISTA certified to perform a variety of tests.


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