3 Things You Need to Know

About Blood Temperature Indicators

Do you trust a product to protect your blood supplies that may “auto activate?” Would you be discarding expensive blood products because of an unreliable indicator?

1. Accuracy Matters

Of the indicators on the market, one is clearly less accurate. “Indicator A” can reach endpoint at 9o, resulting in wasted blood – blood that may actually be in compliance.

2. Performance Varies Greatly

The fine print for a competing indicator clearly states that AFTER ACTIVATION, the temperature of the blood needs to be brough back down to its 8oC “Stop Temperature” to avoid premature indication.

This means that the indicator could prematurely indicate at a temperature as low as 8oC if the blood bank doesn’t take the extra step to ensure that the blood – after attaching an activated indicator – is cooled below this “stop temperature.”

3. Lower Price May Not Be Lowest Cost

Comparing indicator purchase price may make it seem like an easy choice.  however, the actual COST of an indicator that is:

  • poor performing
  • less accurate, or
  • unreliable

is dramatic in comparison to the cost of wasted blood products.

Knowing that, on average:

  • blood banks receive a significant amount of issued blood back
  • ONE unit of wasted blood may cost the blood bank $250
It only makes sense that a more reliable indicator that reaches endpoint at 9.6oC (and not as low as 8.0oC) is a more cost effective choice.

Handy Tip

Safe-T-Vue lot-by-lot QA documents are posted here on our website for easy customer access – and prove that Safe-T-Vue is manufactured to quality standards.


Cooler Validation: Comparison of “Manual” Thermometer vs. “Automated” Data Logger Methods

In our March 2012 survey of over 70 blood banks, many respondents generally described cooler validation as a “pain,” characterizing it as time-consuming, frustrating and even primitive.

Most blood banks revalidate their transport coolers annually. And although it is only once a year, there never seems to be a good time or resource-efficient way to do it.

Using multiple data loggers allows more accurate temperature mapping of the cooler interior.

The three key factors we hear repeated most often are:
1. Time Efficiency (technician’s time)
2. Data Accuracy
3. Simplifying Documentation

At the SCABB/CBBS meeting last month, we entertained compelling discussions with blood bankers who have switched from manual cooler validations with thermometers, to using data loggers (electronic temperature recorders). Some of them are using the Val-A-SureTM Cooler Validation Kit.

If you’ve ever considered switching to an automated validation process, we thought it might be helpful to share what we’ve learned from blood bankers across the country. In the following table (next page) we compare the traditional “manual” thermometer method to the “automated” data logger method – and capture how it has changed their validation experiences.

This graph displays temperature of the top bag vs. the bottom bag. The data is downloaded from data loggers and printed for permanent validation documentation, eliminating handwritten and transcribed data.

We’ll be giving away a Val-A-Sure Cooler Validation Kit at AABB 2015, so if you’re interested in a “free” chance to change your cooler validation method, be sure to stop by and see us!

Jeffrey Gutkind

P.S. For more on Transport and Storage Coolers, check out our Tips, Helpful Ideas and AABB Standards References on www.williamlabs.com.

COMZ VUEPOINT – Cooler Validation-Comparison of Manual Thermometer vs. Automated Data Logger Methods – web version (doc. 2341)

Blood Bank Refrigerator Setpoints Matter

Learn about these important time/temperature correlations relative to your day-to-day blood bank operations.

Understanding the time pressures of busy blood banks, it would be fair to say that ANY time/temperature “advantages” – such as revisiting the refrigerator setpoint – might be worth consideration. Learn more in this VUEPOINT.

by Jeffrey Gutkind, Temptime

Over the past several months I’ve had the opportunity to visit some of the largest blood banks across the nation. In the course of talking with blood bankers about maintaining blood temperatures during storage, issue and transport, I observed a wide range of refrigeration setpoints, anywhere from 1.5oC to 4.7oC.

Reviewing my observations from these visits and reflecting on the AABB standard of 1.0oC to 6.0oC for storage, it brought me back to the “starting” temperature for blood when it’s removed from the refrigerator.

    • How does even a degree or two at a higher or lower storage temperature affect the blood temperature as it is dispensed and issued from the blood bank?
    • More importantly, how does the refrigerator setpoint affect how much TIME you have before the blood reaches 6oC?

To answer these questions, we asked Marielle Smith, Technical Service Scientist, to run a simple test in our lab.

How long does it take for refrigerated blood products to reach 6oC?

Blood Storage Temperature: 2°C vs. 4°C

The following table and graph show the time it takes for the core temperature of a refrigerated blood bag to warm to 6°C when removed from refrigerated conditions (2°C or 4°C) and placed on a counter-top at room temperature.1

The graph demonstrates that the lower the refrigerated storage temperature, the more time it takes for the blood bag to reach 6°C when warming at room temperature conditions. While these results are specific to the test method and setup used, they should be typical.

In terms of practical, day-to-day blood bank operations, what does this tell us?

Based on this test data, it suggests that blood bankers have over twice as much time to get blood issued and dispensed when the refrigerator setpoint is lower (2oC vs. 4oC). This represents a significant advantage for refrigerating blood at lower temperatures and longer times out of refrigeration before the blood goes out of specification.

Knowing that AABB guidelines state blood can be stored at 6oC for up to 42 days and transported between facilities below 10oC, and at the same time understanding the time pressures of busy blood banks, it would be fair to say that ANY time/temperature “advantages” such as revisiting the refrigerator setpoint might be worth consideration.

What do the blood refrigeration experts have to say?

After researching refrigerator setpoint specifications for a number of different vendors, we found that the factory setpoint is typically 4.0oC. Not being a refrigerator expert, I decided to reach out to Colleen Holtkamp Market Manager from Helmer® Scientific, to learn more. Colleen graciously provided these thorough answers to my questions, as well as thoughtful guidance for your consideration on setpoints, alarms and refrigerator specifications. (Colleen’s responses are in blue following the questions).

1. What is the typical factory setpoint temperature of your refrigerators when they go into the field? Are these setpoints easily changed, or does it have to be reset by the factory?

“The typical setpoint for Blood Bank Refrigerators is 4oC. Per AABB Standards, the acceptable temperature for storage of whole blood and most red cell components is 1oC to 6oC. Setting the temperature to 4ºC, close to the middle of the range, is standard practice for blood bank refrigeration.

It should be noted that the alarm setpoints are important, as well. AABB Standards state that alarms should be set to activate before blood components are exposed to unacceptable conditions. For example, since the lower limit for blood storage is 1oC, it makes sense to set the low alarm to 1.5oC (and since the upper limit is 6oC, a high alarm setting of 5.5oC is appropriate).

The ability to change the temperature setpoint depends on the manufacturer/brand of the refrigerator, as does the process for changing the alarm settings (instructions should be included in the refrigerator’s user manual).

Helmer Scientific Blood Bank Refrigerators enable the operating setpoint and alarm settings to be changed at the facility (they do not have to be reset by the factory). With temperature and alarm settings, it’s important to remember that while it should be reasonably convenient to modify them, it shouldn’t be so easy that they tend to be changed by mistake. A safeguard such as password protection for the refrigerator settings offers the best of both worlds – security and ease of use.”

2. Is there some type of statistic that you would use to say if the door is open for 3 minutes per hour; it will take XX minutes to get back down to the original setpoint?
As an example: If the refrigerator is set to 3.0oC and the door is open for 2 minutes, how long will it take for the refrigerator to get back down to the 3.0oC setpoint?

“There isn’t a standard method for measuring temperature recovery after a door opening. It can be impacted by variables such as ambient temperature and how much cold product is stored in the refrigerator at the time. What is important is that the unit has a heavy-duty, forced air refrigeration system and that the fan stops running while the door is open so that it does not blow out the cold air. In addition, the refrigeration system should be powerful enough to circulate the air inside the cabinet multiple times shortly after the door is closed, ensuring quick temperature recovery.

Another consideration is the importance of alarms. Having both a door open alarm and a high temperature alarm provides two layers of protection against temperature excursions due to door openings.”

3. What is the typical tolerance for blood bank refrigerators? (we found this information difficult to find in our online research).

“Blood Bank requires the tightest temperature uniformity of any cold storage application. The typical temperature uniformity specification for Blood Bank Refrigerators is +/-1oC. While not necessarily a regulatory requirement, many Blood Banks have written this specification into their internal protocols/SOPs. Therefore, it has become a community standard that drives performance expectations for Blood Bank Refrigerators.

Before a Blood Bank considers changing refrigerator setpoints from 4oC to 2oC, it is critical to think about the following information. If a blood refrigerator is set to 2oC, with uniformity of +/-1oC, the temperature inside the unit might reach the lower limit of the acceptable range (1oC). Also, if the low alarm is set to 1.5oC (which is advisable because AABB standards state that alarms should activate before blood is exposed to unacceptable conditions), it may be triggered by operation at 2oC. Helmer Scientific’s priority is to optimize the temperature of the blood bag while it is stored in our units. The setpoints and alarms are established to protect the blood while it is in the refrigerator.”

When it comes to blood bank refrigeration setpoints, what have we learned?

• The typical factory setpoint for blood bank refrigerators when delivered from the manufacturer is 4.0oC
• The ability to change the refrigerator setpoint at the blood bank varies by manufacturer
• Blood that is stored at 2oC takes over twice as long (approximate, based on our test) to reach 6oC at ambient, when compared to blood stored at 4oC
• Temperature recovery of refrigerators is affected by a number of variables (door opening, amount of stored cold product, ambient operating temperature)
• Low and high alarms, as well as open door alarms, are important and recommended by the manufacturers

If you have any recommendations, experiences, questions or ideas relative to refrigerator storage temperatures and your blood bank, we’d love to hear from you. Please POST A COMMENT or email us.

Jeffrey Gutkind

1Test Details
At each storage temperature, a total of six (6) simulated blood bags were tested. Each 600mL PVC blood bag (Charter Medical) was filled with 350mL of a mixture of 10% glycerol and 90% water, to simulate red blood cell volume. The bags were removed from refrigerated storage (at 2°C and 4°C) and then placed lying flat on a counter-top at room temperature (at approximately 21°C with 30% R.H). The temperature was measured by placing a calibrated temperature-sensing probe in the center of the simulated blood mixture inside the bag and the temperature was monitored using a calibrated Oakton Thermistor Thermometer. Temperature readings were recorded at 1 minute intervals. The data represents the time needed for the simulated blood mixture (10% glycerol with 90% water) to warm to 6°C.

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Reduce RBC and FFP Waste, Improve ROI

Learn more from this Blood Transport and Storage Initiative that resulted in significant ROI

by Jeff Gutkind, Business Development Manager

I recently read an article in the journal Transfusion1 in reference to reducing red blood cell (RBC) and plasma (FFP) waste.  The study showed significant reduction in RBC and FFP waste by using a new blood transport and storage system, and a significant return on their investment in the new system (estimated savings of $9000/month for their institution).

While the article doesn’t speak to temperature indicators, it does seem to validate that there is a trend toward cooler storage in the OR being considered “intraoperative storage,” which is significant.

For those of us sensitive to blood waste (and associated costs) due to time-temperature issues, this study has a wealth of valuable information and powerful messages:The article cites a national waste rate for hospital-issued blood products ranging from 0% to 6%, and a common reason for blood waste being inadequate intraoperative storage.2

  • The article describes how most of their blood waste was from either temperature or time (away from the blood bank) excursions, and that 70% of those losses came from blood product issued to the OR in coolers.
  • In the second paragraph they state that “AABB standards require red blood cell and plasma units to be maintained at a temperature of 1-10°C during transport and 1-6°C during intraoperative storage.
  • They go on to state (under Materials and Methods) that “holding product in the OR represents a storage condition“….. and “the storage (1-6°C), not the more lenient transport (1-10°C) temperature range needed to be maintained.”

Their previous procedure was to issue blood products to the OR in off-the-shelf commercial coolers that were validated to hold product at 1-10°C for 8 hours. They changed to a new, more expensive cooler that incorporated specialty phase change material that is validated to hold 1-6°C for 18 hours. As a result of the new system and strategy, they have improved their “storage” compliance to 1-6°C and reduced waste from 1.20% to 0.06%, which they calculate to save the $9,000 per MONTH.

The result of this study suggests that incorporating a new, longer duration blood shipping and storage container has allowed the OR to store blood for up to 18 hours at 1-6°C while meeting AABB’s more strict guidelines and has produced significant cost savings and notable return on investment 

It would be interesting to see the savings if they incorporated a Safe-T-Vue 6 indicator in this study.


1. Brown MJ, Button LM, Badjie KS, Guyer JM, Dhanaroker SR, Brach EJ, Johnson PM, Stubbs JR. Implementation of an intraoperative blood transport and storage initiative and its effect on reducing red blood cell and plasma waste, Transfusion 2014;54: 710-07.

2. Heltimiller ES, Hill RB, Marshall CE, Parsons FJ, Berkow LC, Barrasso CA, Zink EK, Ness PM. Blood wastage reduction using Lean Sigma methodology. Transufions 2010;50: 1887-96.

Tips for Better Blood Handling

Lessons you’ve taught us – and why they work!

Keeping blood cold can be a challenge. Here we present a few EASY handling procedures that can be readily incorporated into the day-to-day receiving and dispensing of blood in your blood bank – and make a significant difference.

You told us in our late 2013 survey what topics were of most interest to you and your colleagues in the blood bank. The most popular choices – by a large margin – were:

  1. Proper handling of blood products, and
  2. Use of temperature sensors in blood transport to the OR and ER/Trauma

Reflecting on the conversations and comments from visitors to our booth at the 2013 AABB in Denver, this survey validated what many of you have told us about keeping blood cold and proper handling.

In this VUEPOINT we are summarizing some of the handling procedures and ideas that blood bankers from around the world have shared with us over the years.

Tip #1

Handling blood bag by edges to prevent warming blood product Always handle blood bags by the ends where there is no blood that may be warmed by normal handling.


Holding a typical 300 – 400 cc blood bag in warm human hands for even 20-30 seconds may raise the core temperature by up to 2°C. The temperature rise is faster in smaller bags (< 350 cc) so extra care should be taken to handle small bags only by parts of the bag where no blood may be warmed by handling.

Tip #2

Always keep cold packs in the blood refrigerator. Place blood bags on a cold pack immediately when removing blood from the refrigerator – MAKE IT A HABIT!


A 350 cc blood bag that starts at 3.5 °C will reach 6.0°C in approximately 6 minutes and approximately 10°C in approximately 19 minutes depending on the temperature of its environment, and the temperature of any surface it comes into contact with (hands, lab bench, etc.).

The same bag on a cold pack, where both blood and cold pack are at 3.5°C and placed on a bench at 20°C will keep the blood below 6.0°C for approximately 14 minutes and below 10.0°C for approximately 36 minutes.

This is a no-brainer! USE COLD PACKS.

350 cc Blood Bag, temperature change with and without cold pack
3.5 °C 6.0°C 10°C
Without Cold Pack START 6 minutes 19 minutes
With Cold Pack START 14 minutes 36 minutes

Tip #3

Using an adhesive temperature indicator on the blood bag is one way to monitor – and be assured – that the blood temperature has not exceeded the upper compliance temperature of 6.0° C or 10.0°C.


Adhesive temperature indicator on blood product gives visual indication

Indicators give visual indication when the blood is approaching the 6°C or 10° C compliance temperature, and then confirm if the blood exceeded temperatures – even if the blood is “re-cooled” to a compliance temperature.


Temperature indicators on blood bags in blood bank refrigerator

Some blood banks have adopted a procedure to apply the indicators to blood bags as they are put in blood bank refrigerator storage – then they can quickly activate the indicator immediately when the blood is dispensed, or activate it at the same time it is applied.

VALIDATION TIP – When validating a blood indicator be certain to use a temperature recorder that measures and indicates to within 1/10th of 1°C accuracy (0.1 °C).


SELECTION TIP – When choosing an indicator, be sure to pay attention to and ASK FOR proof that the product has been cleared through the 510(k) process by the FDA. This can be verified by receiving the product’s FDA 510(k) registration number from your supplier. To learn more about FDA 510(k) registration, read this VUEPOINT.


Do You Have Any Tips To Share?

  • Are there other procedures or ideas from your blood bank that we can share?
  • Do you have unanswered questions that we can help you get answers to?

Your peers, in hundreds of blood banks around the globe, are always eager to learn from each other. Please pass on your Tips for better blood handling, and we will be sure to post them in the next VUEPOINT.

Blood Temperature Compliance at 6°C … is it safe to re-inventory?

When blood products are issued from the blood bank in a packed cooler and are later returned to the blood bank, how do you know if the blood was maintained at the compliance temperature of 6°C? In this 90 second video, you’ll see how Safe-T-Vue® 6 from William Laboratories (www.williamlabs.com) can be used throughout the transport and temporary storage process to provide easy visual indication if the blood temperature exceeds 6°C.