Temperature-Sensitive Labels for Containers of RBCs

Viviana Johnson, MD; Albert Langeberg, MT; Addisalem Taye-Makuria, MD; S. Gerald Sandler, MD


Am J Clin Pathol. 2006;126(3):411-415. 

In This Article

Abstract and Introduction


Temperature-sensitive labels are adhesive tags that display color changes at preset temperatures. There have been no studies of the suitability of this technology for measuring the temperature of blood components during transportation and storage. We used a digital thermometer to measure temperature in different locations inside containers of RBCs as they were allowed to warm to ambient temperatures following removal from refrigeration. We compared these temperature readings with those of 3 temperature-sensitive labels. These labels are marketed to alert transfusion services if the temperature of blood bags exceeds 10B0C, which is the maximum permissible by Food and Drug Administration and American Association of Blood Banks requirements for transporting RBCs. The contents of refrigerated RBC units changed from one homogeneous temperature to a range of temperatures when containers were allowed to warm (undisturbed) to ambient temperatures. Color changes of all 3 temperature-sensitive labels correlated more with core compared with surface temperatures of RBC units. These devices add an additional dimension of safety to the conventional 30-minute rule, which limits storage of blood components at ambient temperature to 30 minutes.


The American Association of Blood Banks and US Food and Drug Administration require human blood or components to be stored at 1B0C to 6°C and not to exceed 10°C when transported.[1,2,3] Ensuring compliance is logistically difficult, however, when blood is stored or transported outside the transfusion service's supervision and control. Specialized storage containers have been developed for long-distance or long-term applications.[4] However, in day-to-day operations, transfusion services typically manage this function according to the 30-minute rule, ie, refrigerated blood components may be held at ambient temperature for no longer than 30 minutes.[5]

In recent years, manufacturers of temperature-sensitive indicators have marketed devices to transfusion ser-vices as aids to ensure compliance with requirements for monitoring the temperature of stored and transported blood components. Two types of temperature-sensitive sticky labels are available for transfusion services. Temperature indicators monitor whether a component's temperature has exceeded a set value.[6]Time-temperature integrators display time and temperature measurements as a single result.[6] Although similar devices are used in the food industry,[7,8] we are not aware of any studies of the suitability of temperature-sensitive labels fixed to the exterior surface of blood containers for monitoring the temperature of blood components outside of temperature-monitored refrigeration. We conducted the present study to evaluate the contribution that temperature-sensitive labels might make to safe transportation and storage of refrigerated blood components.


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