The standard ISTA 7D evaluates the effects of temperature exposure on temperature-controlled transport packages. It measures the ability of a package to protect a temperature-sensitive product from temperature extremes encountered during transport. The test exposes the packaging and product to temperature cycles that simulates transport during summer and winter months. The standard can be used for individual or comparative performance analysis of standard or insulated transport packages against conditions normally encountered during transport.
ISTA 7D testing is used by a wide range of industries to gauge the thermal performance of packaging designs. Some of the industries served include the medical, pharmaceutical, and food-product suppliers that require cold chain compliance to maintain sustainability of perishable items.
Quest Engineering Solutions is an ISTA certified laboratory that specializes in ISTA 7D testing. This testing is required by Walmart for all cold chain/perishable sellers who require third party validation on their shipping methods in order to become approved to sell via Walmart Marketplace. This testing is also critical for shipments of some pharmaceutical and medical products. Quest performs cold chain testing for major biomedical companies. Quest Engineering Solutions is recommended by Walmart Marketplace as a third party provider of this service, and also has extensive experience working with pharmaceutical and medical products.
The testing itself involves assembling one or more of your packages in the same manner as how your shipping team would assemble the package(s) prior to shipment to its next destination. This involves placing preconditioned gel-packs, PCM panels, or dry ice in your package(s), in accordance with your specific pack-out instructions, along with the refrigerated or frozen product(s). Thermocouples, or other temperature measurement devices, are then installed inside or around the product(s) and the package is sealed. The installation of the temperature measurement device allows for the temperature at the location of the perishable product to be measured and recorded over time.
The below graphic illustrates a typical pack-out configuration of a food product that is shipped with frozen gel packs.
After the package(s) have been prepared and sealed, they are then placed in an environmental chamber to undergo ISTA 7D temperature cycling, as depicted in the below image. The testing is designed to simulate temperature extremes experienced by the package(s) during summer and winter months. This is achieved by performing separate ISTA 7D summer and winter temperature cycling profiles. The exact length of the profile depends on whether the final destination is international or domestic, and will typically include considerations for the anticipated worst-case shipping time. For example, an overnight shipment may need a 48-hour test in order to account for possible shipping delays. Test durations can range anywhere from 24 to 96 hours, or longer.
A typical 48-hour ISTA 7D Summer and Winter profile for a domestic shipment consists of the below temperature cycling steps. In this example, the temperature is cycled in an environmental chamber for 48 hours per profile, while the inside of the shipping container is monitored.
The results of the test are then plotted and analyzed to determine whether the packaging solution can adequately keep the product at acceptable temperature limits throughout the selected test duration. In the below example plot, the 48 hour summer profile has been performed on packages that were packed with dry ice at the start of the test. The chamber temperature (plotted in light blue) follows the summer profile defined in the above table, while the other plotted lines represent the temperature rise over time of different test sample configurations and package designs for the purpose of choosing the best performing option.