Qualification standards for insulated packaging

“Application of a reference system is optional unless regulations make it mandatory.”

In order to guarantee an acceptable level of quality and security for temperature-controlled containers, reference regulations and standards, as well as good practice guides, have been established by different bodies in different countries. Some come from standardisation bodies authorised by the Countries and have the status of norms. Others are written by associations or industrial groups and have the status of standards or guides. In both cases, they are established by consensus by the relevant stakeholders. The application of a reference system is optional unless regulations make it mandatory.

These reference systems provide protocols and procedures for characterising containers and verifying their ability to maintain the products within a required temperature range. They have common elements and criteria but differ in others.

Different types of reference systems 

We differentiate between different additional reference systems within the field of temperature-controlled distribution of healthcare products.

Regulations: these are a set of requirements and rules governing an activity. Regulations are written by competent administrations and their application is mandatory.

Standard: this concerns a reference document describing a method for qualifying a temperature-controlled container, formalised by an independent body authorised for that purpose by a national or international community (ISO, AFNOR, DIN, ASTM, BSI, NBN, JSA…). It reflects the current state of knowledge at the time it is written, the means and methods described must be reproducible.

Benchmark: this is a document similar to a standard but formalised by a group (consortium) of suppliers of products or services and users. It is intended to assist with the compatibility of products and services from different origins. When a method or a process is necessary for users, it acquires a standard character.

Guides and recommendations: a guide is a document bringing together information on a theme which serves as a benchmark. Recommendations are guidance on good practice.

Principal parameters of thermal qualification protocols

Certain parameters and criteria are shared between the qualification reference systems. Others differ. They may therefore promote or oppose the test results, making comparison of the efficiency of insulated packaging solutions very difficult, or impossible.

Common criteria

The calibration and qualification of the equipment used to perform thermal efficiency tests are similar (test chamber and measurement system). The majority of reference systems require no integration of instrumental uncertainties which favours the performance results. Certain elements of the preparation procedure are based on the same principles: the instrumentation and thermal stabilisation of the boxes, eutectic plates or phase-change materials (PCM) and products.

Criteria differentiating standards

Scope of application: The scope of application may be broad or narrow (insulated containers in general, insulated containers for healthcare products or insulated containers for a category of products). Guides may address storage and shipment and include a risk analysis.

Temperature profiles: A temperature profile simulates the variations in temperature in a logistical circuit, from loading the temperature-controlled container until unpacking. This is the parameter considered most by users which often associate qualification with the profiles used. Some even forget the importance of other parameters. The temperature profiles may be cyclic composed of segments or at a constant temperature.

Certain reference systems recommend temperature profiles with different requirement levels; others leave the choice and responsibility to the user and the manufacturer.

Test load and loading level: The test load and the loading levels are also non-harmonised points. Actual products are rarely used in thermal efficiency tests. They are generally simulated by a test load which, depending on its thermal inertia, plays an important role in the results. Empty vials represent a worst case scenario in thermal inertia. The vials or pouches filled with water clearly support the test results. Some reference systems specify the test load and the minimum and maximum loading levels; others are limited to recommending a representative load.

Number and positioning of sensors: The results of the thermal efficiency tests depend on the number and position of temperature sensors. The containers present temperature heterogeneities. The warmest and coldest points depend on the configuration tested, particularly the positioning and temperature of the energy source and the temperature profile.

Certain reference systems do not address this issue or approach it tentatively, by providing recommendations on the positioning of sensors, allowing the possibility of interpretation and the responsibility to whomever applies the protocol. Some reference systems specify the number and location of the temperature sensors.

Preparation of the configuration: In addition to thermal stabilisation of the elements, reference systems may establish the temperature and loading time for containers.

Conformity of packaging: Each qualification reference system specifies the conformity criteria for qualified packaging. Only the NF S 99-700 standard requires measurement uncertainties in the declared conformity to be taken into account.

Comparison of the main thermal packaging qualification reference systems

Comparison of the main thermal qualification reference systems is established according to the parameters and criteria presented above. Only the reference systems describing a thermal qualification method for temperature-controlled boxes are considered.

• NF S 99-700: French Standard
• ASTM D3103-07: US Standard
• DIN 55545-1:2006-03: German Standard
• ISTA 5B combined with 7D and 7E: Guide, procedure and standard
• WHO/IVB/05.23: WHO Guidelines. This is considered because it provides temperature profiles as well as the number and positioning of sensors.
   

Conclusion

The reference systems NF S 99-700, ASTM D3103-07 and DIN 55545-1:2006-03, have the status of a standard because they are established by official standardisation bodies. Among these reference systems: 

• Only the NF and ASTM standards provide thermal qualification for temperature-controlled packaging.
• The NF S 99-700 standard is the most comprehensive because it provides two protocols (one standard and one specific), a standard test product, 21 temperature profiles from 1 to 96 hours for the full year, as well as the number and positioning of sensors.
• The DIN standard does not provide qualification that guarantees a sufficient level of security.

The ISTA 5B guide, the ISTA 7D procedure and the ISTA standard do not have the status of a standard. These documents are supplementary and combining them (merging) in a single protocol or with the ASTM D3103-07 standard can result in thermal qualification.

The tests provided by WHO/IVB/05.23 from the WHO guidelines represent stress tests and do not represent the conditions of an actual logistical circuit. It can be in addition to another reference system but does not result in a relevant thermal qualification alone.

Only the NF S 99-700 (AFNOR) standard requires measurement uncertainties in the declared conformity to be taken into account.