ASTM vs ISTA: What to Consider When Choosing Your Transit Test Method
The medical packaging industry is well familiar with ISO 11607 Part 1 which states, “The packaging system shall provide adequate protection to all sterile barrier systems and the sterile contents through the hazards of handling, distribution and storage.” Two test standards are widely used in the medical device industry (and recognized by the FDA) to meet the requirements of ISO 11607: ISTA 3A and ASTM D4169. These are consensus standard practices that provide a basis for simulating, in a laboratory, the ability of medical device packages to withstand worse-case dynamic forces within a distribution environment, including: shock and vibration, compression, temperature, humidity, mode of transportation, and pressure changes. So, if both standards are widely used, what’s the difference? How do you know which one to choose? Here is a figure that compares how dynamic forces are interpreted from the two standards:
| Order |
ASTM D4169, DC13, AL1 |
ISTA 3A (Standard Box) |
|
Conditioning |
Climatic Conditioning
|
Climatic Conditioning
|
|
1 |
Drops (Schedule A)
|
Drops
|
|
2 |
Compression (Schedule C)
|
Compression
|
|
3 |
Fixed Displacement Vibration (Schedule F)
|
Fixed Displacement Vibration
|
|
4 |
High Altitude (Schedule I, non-porous packaging)
|
High Altitude (non-porous packaging)
|
|
5 |
Random Vibration, Truck (Schedule E)
|
Random Vibration (with Top Load)
|
|
6 |
Random Vibration, Truck (Schedule E)
|
Random Vibration (without Top Load)
|
|
7 |
Concentrated Impact (Schedule J)
|
Concentrated Impact
|
|
8 |
Drops (Schedule A)
|
Drops
|
One of the more frequent questions Packaging Compliance Labs receives is “which test method is more severe: ISTA 3A or ASTM D4169, DC13?” Unfortunately, there is no industry consensus on that question, and choosing which method is representative of “worse-case” is dependent on the product packaging system. My advice is to understand the differences between the two standards and apply those to your specific design.
For example, if a product packaging system consists of flexible single barrier pouches in a shipper, we can determine compressive dynamic forces will only be absorbed by the corners of the shipper before affecting the device because the flexible pouches are not load-bearing. ISTA 3A random vibration, which includes top load, may not be the appropriate test method selection as it introduces unnecessary dynamic forces to the test environment. On the other end of the spectrum, if a packaging system consists of rigid double barrier, thermoformed trays within a shelf carton and shipper, we can determine that compressive forces will be absorbed by multiple packaging tiers to protect the device. However, the device may be fragile (which is why we are utilizing more packaging materials), so may be more vulnerable to shock from drop testing. In this case, ISTA 3A may be the more appropriate test method for simulating a realistic worse-case scenario.
There are many elements that could impact the success of your transit testing activities - consider the performance features of your product packaging system before selecting a standard so that you can rationalize choosing one standard over the other. As a general rule, once you’ve selected a standard for a specific configuration or product family, stick with it. The FDA looks for consistency so switching standards used may create a red flag: why did they switch?
Note: this is the independent opinion of PCL technical experts and not the opinion of either ASTM or ISTA
