Updates to Procedure 3E: Unitized Loads Test
Eric Hiser, ISTA Vice President of Standards and Certifications
ISTA has approved updates to ISTA Procedure 3E: Similar Packaged‑Products in Unitized Loads for Truckload Shipment Test following a technical review completed through ISTA’s ANSI‑accredited, consensus‑based approval process.
These updates are intended to improve alignment between laboratory testing and real‑world distribution hazards, while also enhancing clarity and testing efficiency. Members and test users are encouraged to review the revised procedure to understand how these updates may affect their testing programs.
Why Procedure 3E Was Updated
The revisions were prompted by two formal change requests submitted by testing and research organizations Smithers and CETEA/ITAL, both of which focused on:- Better reflecting real‑world distribution hazards
- Improving compression testing practices
- Clarifying impact test sequencing
Summary of Key Updates
Compression Formula Alignment- The compression formula has been revised to revert to the previous ISTA 3E approach.
- This update aligns Procedure 3E with the recently revised compression formula in ISTA Procedure 3H.
- Clarifying language now specifies that the largest stack, whether in warehouse or vehicle conditions, is used when calculating compression.
Optional Pallet on Top During Compression Testing
- The revised procedure allows an optional identical pallet to be placed on top of the test sample during compression testing.
- Additional guidance explains that adding real‑world distribution elements (such as a pallet on top) may justify adjustments to the safety factor when appropriately supported by the test user.
Impact Sequence Clarifications
- Updates to incline, horizontal, and rotational impact sequences provide greater flexibility in how tests are performed.
- All required edges or faces must still be impacted.
- These changes correct previous clerical inconsistencies and improve laboratory testing efficiency without changing test severity or intent.
How the Changes Were Approved
- The proposed updates were first reviewed by the ISTA Standards Council. A dedicated workgroup representing testing laboratories, academia, manufacturers, retailers, and logistics providers evaluated the changes.
- The workgroup reviewed historical data, prior revisions, and supporting rationale before submitting recommendations.
- The Standards Council unanimously advanced the updates to the Test Series Group, ISTA’s consensus body.
- The changes were approved through formal voting, with no negative comments, reaffirming Procedure 3E’s American National Standards (ANS) status.
Accessing the Updated Procedure
The updated ISTA Procedure 3E is available in the ISTA Store and is free to ISTA members with login access. It can be downloaded as:- An individual procedure, or
- Part of the ISTA Resource Book