Making sense of storage, transport, time and temperature

Recent conversations on PathLab Talk surrounding the 30-minute rule are drawing new attention from blood banks, whose interpretations of the AABB, FDA and CAP guidelines are ever-evolving.

The title of a presentation made at AABB 2015 (9108-QE) in Anaheim says it all:

“Making Sense of the Reissue Standard: Storage, Transport, 30-minute Rule, Coolers, Continuous Monitoring, USBs, Wireless Systems….How to Best Meet It Without Pulling Your Hair Out!”

The “word on the street” was that while AABB still allows the 30-minute rule, the new requirement is that the process must be validated and documented.

In this article, we will present information on blood reissue, based on content from this AABB presentation, CAP and AABB guidelines, and our work with two major U.S. hospitals. Specifically, we took into consideration information these hospitals have shared relative to interpreting return requirements and validation criteria to maintain compliance and safety for their patients.

The Guidelines

Simply stated, AABB Standard 5.26 and FDA Regulation 21 CFR 640.2 establish these return requirements relative to temperature:

  • Appropriate temperature
    – – – has been maintained (AABB)
    – – – blood has been continuously stored 1-6°C or transported 1-10°C
  • Records indicate the temperature inspection was performed and was acceptable

CAP TRM.42470 states:
“Acceptance Back Into Inventory: There is a written procedure validated by the laboratory, for accepting blood/blood components back into inventory after they have been issued.

NOTE: The procedure must include steps to verify the integrity and appearance of the container and maintenance at appropriate temperatures.  The steps and criteria defined in the procedure for acceptance of units back into inventory, such as the “30 minutes” rule, must be validated by the laboratory.”1

AABB Technical Manual, 18th Edition:
“Validation is used to demonstrate that a process is capable of consistently and reliably achieving planned results.”2

The Common Theme: Validation of the Process

As pointed out in the AABB 2015 presentation, “return criteria for temperature is directly related to the validation….”. With the “30-minute rule” the focus has been on TIME. In contrast, all of the guidelines focus on TEMPERATURE. And it is the documented validation of your process(es) that proves the consistent maintenance of temperature, continuously, for the life of the process.

It may sound easy, but can you accurately validate your process(es) – specifically, continuous temperature maintenance, from the time blood is dispensed until it is returned? Let’s consider all the points in the process that may require validation.

Validation Points

Let’s assume you dispense blood in validated coolers. Great! But have you validated the PROCESS for each (possible) step? Have you validated for every possible scenario – each validation point? For example:

  • Every blood product
  • All sizes/volumes of blood products
  • All possible packing scenarios – one bag, 3 bags, more?
  • All possible transport scenarios or “paths” and the time/environment associated with each – hand-carry, pick-up, cooler, pneumatic tube system
  • Recipients or destinations – each OR, ED, patient rooms, floors, nursing stations

Your validation documentation must show that your process is (1) consistent over time and (2) with exact temperatures. One of the hospitals we spoke with said this would be virtually impossible for them, since there are so many scenarios in their institution due to the hospital size, and the number of ORs and patient rooms.

Thinking of it this way, is it POSSIBLE to validate the “30 minute rule” in your institution? More important, can you actually capture and document a wide enough range of scenarios in your process, taking into consideration all the variables? Are your processes that consistent? And would it be worth the time it takes to validate all of the potential scenarios?


The latest interpretation is that the 30-minute rule can be used, but only if the entire process was validated.  When you can validate you process per CAP, AABB or FDA guidelines, “30-minutes” becomes a non-issue.  As long as you have validated the process to prove that the temperature can be consistently and continuously maintained at acceptable storage/transport temperatures, the time factor is no longer applicable.


Processes incorporating temperature indicators require few validation steps – AND provide more reliable indication of temperature “history” of the blood product for the entire time it is out of blood bank control.  Because the indicator is validated, using an indicator shows if the blood is kept at an acceptable temperature from the time it leaves the blood bank until it is returned.

Clearly, using a temperature indicator such as Safe-T-Vue is more time efficient and reliable at validating the entire process.  And, if the unit is out longer than its time limit (whether 30 minutes or 4 hours), the unit can be deemed acceptable on return if the indicator shows that the temperature has been continuously maintained, thus resulting in less waste and overall, more cost-effectiveness.



1. CAP Guideline TRM.42470 

2. AABB Technical Manual, 18th edition