Applying ISTA PCG-02 Passive Thermal Packaging System OQ Best Practice Guidelines

In 1785 milkmen began delivering milk in reusable jugs, pails, and jars. The first reusable packaging, perhaps? Over the last 236 years, the idea is the same: deliver your product in the condition and temperature you require. For some time, consumers and corporations alike have used both disposable and reusable thermal packaging to regulate the temperature of goods in transit. But as the industry has matured and more life sciences applications require temperature control, the number of manufacturers producing packaging solutions has increased the need for industry standardization. Adding onto this is also the environmental concerns plaguing the packaging industry. Think about ten gel packs in a cooler multiplied by thousands of coolers shipped every month. Environmental concerns require new technologies and new ways of thinking about minimum standards for those technologies. Reusable solutions, for example, demand more rugged packaging materials to make them reusable. What was needed was an enhancement of existing guidance to meet this new challenge.

In November 2020 the ISTA Pharma Committee of the International Safe Transit Association (ISTA) published the PCG-02 Passive Thermal Packaging System Operational Qualification Best Practice Guideline.  Leading experts in cold chain packaging from the pharmaceutical and life sciences industry authored this document to provide guidelines for the passive thermal packaging operational qualification process that defines the minimum requirements and drives standardization among packaging providers and life science companies.

Standardization of both process and testing acceptance criteria allows manufacturers and suppliers to reduce customization, mix and match components, and test new environmentally friendly materials cost-optimized to meet customer needs. It also sets a baseline standard for manufacturers to develop solutions that are qualified under the same criteria. Standardization removes questionable practices, benchmarks new technologies, and can also speed time-to-delivery.

Although companies may have different requirements for shipping and distribution, how manufacturers, suppliers, and testing labs apply this guidance is an essential aspect of creating risk-averse packaging. The team at TempAid Labs specifically applies these standards and processes for running a cold chain packaging lab more efficiently and with a high degree of data accuracy.

The updated guidance is divided into several sections. We’ve highlighted a few of them here that may be of concern to our customers.

Passive thermal package testing. The ups, downs, and other orientations of your packaging.

The first part of the guidance document describes the setting up of a thermal packaging test.  It starts with the base instrumentation and conditioning environments to be set up and validated in preparation for the study.  Just as we do in our lab, each component of the thermal package (cooler, gel pack, etc.) needs to be conditioned correctly, and the sample payload/product instrumented with temperature sensors or data recorders calibrated per the test protocol requirements.  The guidance describes thermocouples as the best practice for temperature sensors but does not rule out the use of other types of devices such as RTD’s (Resistance Temperature Detectors) or thermistors.  Stated recommendations:

• Probes must be placed in such a way as to measure actual product temperatures, or as close to the product temperature as possible.
• There also should be another probe monitoring the environmental chamber’s ambient air temperature to ensure the temperature profile runs correctly.

The guidance recommends using the procedure defined in ISTA Standard 20 but layering onto it a risk-based approach to the number and placement of sensors to ensure the areas of most temperature vulnerability are monitored during the study.  It is recommended the temperatures be recorded throughout the test with a measuring interval of 5 to 15 minutes as best practice.  The tested product load should represent a bracketing of the minimum and maximum product loads.

The guidance also notes a section on package orientation, which is often overlooked when defining a cold chain packaging test protocol.  This is particularly a problem where the designer of the packaging cannot ensure it is shipped in any specific orientation.  Passive thermal packaging is seldom symmetric across all sides, often with differing refrigerant amounts, types, or conditioning.  This can result in different packages that do not function identically depending on which side is facing down during transit.  The guidance recommends conducting a risk assessment to determine if a package will perform when in a different orientation.  If the worst-case orientation can be determined either through thermal modeling, design qualification testing, or another method, then performing OQ testing with the package in its worst-case alternative face orientation is recommended.  There is also a recommendation for conducting mechanical testing, such as one of the ISTA series tests or ASTM D4169.  Such testing can help evaluate the likelihood of package orientation affecting thermal performance and determine that the package protects the product from physical hazards.

Documenting the testing process and results

Best practices for documentation of the testing process and results are also outlined in the ISTA Guidance.  A series of documents are needed for any complete OQ test sequence, including:

1. The Thermal Operational Qualification Protocol document outlining the requirements for the test series. It should be managed with a revision control process that includes approvals from technical and quality representatives before starting the lab study.
2. An acceptance criterion typically covers the acceptable temperature range outlined in the User Requirements Specification created before starting an OQ.
3. An identification of parties responsible for the action items and process deliverables.
4. A test plan outlining all of the included variables, including but not limited to
   • the ambient temperature profiles,
   • the payload,
   • the number of packages to be tested,
   • preconditioning requirements, and
   • all sensors, environmental chambers, and other equipment

Once the OQ study is complete, a Thermal Operational Qualification Report needs to be generated, reviewed, and approved with a revision control process.  It should include the following sections:

1. A summary of the test results, including charts showing the temperature sensor measurements presented as a temperature versus timeline graph. The report would include both the internal product temperatures and the ambient chamber temperatures, all on the same chart.
2. It is also considered best practices to include data showing the preconditioning temperatures for the components to show they were at the proper temperatures before starting the study.
3. Certificates showing the temperature sensors were successfully calibrated prior to the study and verified afterward should also be included. These certificates prove the temperature recordings during the test were accurate.
4. A conclusion stating whether the acceptance criteria was met should then be followed with the raw data and any attachments needed to understand what was done during the study thoroughly.
5. The guidance then examines many parts of the process outlined above with detailed examples of how the testing documentation and processes would look if conducted per the recommended best practices.

As we move into the next generation of environmentally friendly and durable packaging, new testing methods and processes are needed to ensure data consistency and accuracy.

For a copy of “Passive Thermal Packaging System Operational Qualification Best Practice Guideline,” visit the ISTA website.

TempAid Labs – Leaders in ISTA best practices

As a member of the ISTA, Rapid Aid’s TempAid Labs follows these best practices, qualifying its newest cold chain packaging equipment with the goal of being fully compliant with complete IQ/OQ/PQ validation of the equipment per the best practice guideline. The company performs mapping studies on its laboratory freezer and refrigerator, qualifying it for preconditioning of test materials per the ISTA Guidance.  The team at our lab specializes in testing and optimizing for consistently in holding the 2°C to 8°C and -15°C to -25°C temperature requirements required by most cold chain packaging test protocols.

Additionally, installation of our newest Thermotron environmental chamber has included following a similar process to show it can maintain temperatures across the ranges required by the ISTA 7D and 7E temperature profiles.  These equipment qualifications are all conducted using our NIST traceable RTD data logging systems.

For more information on the ISTA, visit their website. For more information on the capabilities of TempAid Labs, visit our services page at https://www.tempaid.net/solutions/packaging-services/.