Urgent Equipment Question

[Brenda K Hutson]

We are having a rather heated debate in the Lab today regarding the monitoring of Refrigerators and Freezers. :mad:I have been a Blood Banker for 26 years but am still a little nervous of letting go of old regulations and I cannot find this addressed specifically in the Technical Manual.

In the past, we had thermometers on our upper and lower shelves of Refrigerators and Freezers, and continuous charts. Then along came the Centralized Temperature Monitoring Systems. It is clear to me that if you have a Centralized System, you do not have to have Charts (and we no longer do). What is NOT clear to me then is the monitoring of internal upper and lower temperatures.

Some time ago (before my time at this Institution), they discontinued taking Manual Temps. of thermometers on upper and lower shelves (though we do still have them in the equipment). The Technical Manual states to take Manual Temps. "daily."

The Centralized Temperature Monitoring System that we use, only has 1 probe in the equipment (so I assume 1 temperature point). Another Institution I previously worked at, discontinued performing Manual Temps. of the thermometers, when they purchased a Centralized System that has both Upper and Lower Probes.

Question (finally): If your Centralized Temperature Monitoring System has only 1 Probe, do you still need to document the upper and lower temperaturers (from thermometers placed on upper and lower shelves), or, is this no longer necessary? If no longer necessary, please provide supporting information.

Thanks much!

Brenda Hutson, CLS(ASCP)SBB

[clmergen]

We refuse to use the centralized monitoring system until they buy us 2nd probes for the bottom of the refrigerator.

[SMW]

I find it's helpful to try to think of the rationale behind the standards or actions and use that as a guide in the process. With that in mind, it's not really documenting the temperature that's important but rather knowing when the temperature is approaching unacceptable levels. Devices shall have the capacity and design to ensure that the proper temperature is maintained (AABB 3.6.1) and the temperature needs to be monitored (AABB 3.6.2) which could be manually or electronically. More importantly, the alarm needs to activate under conditions that will allow proper action to be taken before blood/components/tissues, etc. reach unacceptable conditions (AABB 3.7.1). An upper and lower shelf were historically thought to represent the two extremes within a device (although temperature mapping often disproves that thought). If your temperature mapping has demonstrated that all areas of the storage device are maintained at the exact same temperature and there are no "hot" or "cold" spots (which is highly unlikely except for very small storage devices), then one probe may be sufficient. If your temperature mapping has demonstrated variable temperatures within the device ("hot" or "cold" spots) then that would determine not only how many probes you may need for that particular device, but would also indicate where the probes should be located (and that may not necessarily be the upper and lower shelves) to ensure that adequate notice is received to rescue the contents in the event of a temperature excursion. Think about what your response would be if/when an inspector/assessor asks you "How do you know that your alarms are activating when an area of your storage device approaches an unacceptable temperature?" and perhaps that can help guide you through the process that would be best for your equipment and facility.

Edited June 26, 2009 by SMW

[RR1]

Another way around this would be to temperature map your fridge, then place your single probe in the area giving the highest temperature fluctuation- you could then discontinue manual checks. This is assuming that there is only one area of concern within the fridge. It would be better for larger fridges to have probes top and bottom.

[Alternatives]

Hi Brenda,

Number of probes within your equipment is not regulated; you need to place enough probes to have a relevant recorded temperature (it depends of the size of you equipment, your products....) You could map your equipment and it will give you hot and cold spot, to help you to determine where to place your sensors and how many.

Basically for regular small fridges or freezers (one door), one probe could be enough, if it is in an open area (no separate walls for example) as there are not a lot of fluctuation inside. But a mapping will confirm you this point.

You could add some others probes like data loggers recording in loop for example, but your probe will be your main evidence that your fridge has kept a good temperature. Calibration, alarms, documentation...etc will be checked on this probe only.

I have some customers who prefer to add some calibrated data loggers, which record in loop, in case of power failure or major break down. These, are calibrated but don't have alarms for example. It's just a back up.

I will provide you documentation and regulatory about this point.

Benoît

Edited June 26, 2009 by Alternatives

[Brenda K Hutson]

I have to admit, though I have heard of temperature mapping, I am not familiar with how it is done. Can you either tell me of a resource, or briefly explain what I would need to do?

Thanks!

Brenda Hutson, CLS(ASCP)SBB

[Malcolm Needs ☆]

Hi Brenda,

There is a separate thread on temperature mapping in the Quality section (USA one).

[shelleyk482]

I guess I have a little different view on keeping the temperature chart. We have a central monitoring system but the monitor for it is located in the main laboratory and there is no way to make sure that someone actually looks at it daily. I feel like the daily look at the tracing is important as it allows us to identify ptential problems before they become significant such as "noise" which may indicated door seal problems, low freon, low glycerin in the probe bottles or if for some reason we are now running near an alarm setpoint but not quite triggering it.

We do have 2 probes, 1 top and 1 bottom, on all of our large units. I will be removing the internal thermometers and just do monthly verification of temperatures using a datalogger with a probe put into the same bottle of glycerin as the Tympsys probe.

[Malcolm Needs ☆]

Apart from local alarms on our fridges, we also have a remote system called Contronics.

This monitors the temperature 24/7/365 and records it. If the temperature seems to be going outside 2oC or 6oC it also sets off an alarm in an area that is staffed 24 hours a day that sounds a bit like a warning of a nuclear attack. It is designed so that it cannot be ignored, and whoever designed it did a VERY good job!

[Alternatives]

I have to admit, though I have heard of temperature mapping, I am not familiar with how it is done. Can you either tell me of a resource, or briefly explain what I would need to do?

Thanks!

Brenda Hutson, CLS(ASCP)SBB

Hi Brenda,

Mapping is much more explained and detailed in pharma industry, where this work is required for storage areas.

The temperature mapping study is the etablisment of documented evidence of the temperature control and distribution inside thermal equipment. The objective is to make sure inside temperature is always homogeneous and in accordance with temperature specified on product.

This study permit to know hot and cold spot inside each equipment, and so guaranty that products are always maintained in a compliant range of temperature. Thus, the gathered data will constitute a source of information in order to store products adequately, according to their specified temperature range.

A protocol is first written in order to describe in details all procedures and how this study is executed. This protocol has to be approved by all involved parties. A report is established at the end.

Data loggers are placed in several points inside each equipment where products are stored, during 24 hours (this lengh of time could be more or discussed). The data logger readings will be done every 5 minuts. (not a regulation but enough to have relevant data without having tons of data if sampling is every minut). Data loggers should be compliant in term of calibration, CFR Part 11...etc

Internal air temperature distribution should be mapped on installation in the empty and full state and annually thereafter under conditions of normal use. Products should not be stored in areas shown by temperature mapping to present a risk (e.g. in the airflow from the refrigeration unit).

Exemple of mapping description for a warehouse in pharma industry (USP 1079): Temperature profiles can be compiled by using a suitable number of thermometers or other temperature recording instruments. They should be placed throughout the warehouse in divided sections and should record the maximum and minimum temperatures during a 24-hour period for a total of three consecutive 24-hour periods. The following factors, some of which may give rise to extreme temperatures, should be considered during the process of temperature profiling: the size of the space, location of space heaters, sun-facing walls, low ceilings or roofs, and geographic location of the warehouse. Temperature profiling for warehouses already in use should be done at known times of external temperature extremes, e.g., for a period of not less than 3 hours when air temperatures are higher than 25 or less than 15. Profiling should be conducted in both summer and winter. A mean kinetic temperature (MKT) should be obtained for any separate areas within the warehouse. The temperature profile report should provide recommendations for the use of each area and identification of any areas that are found unsuitable for storage of Pharmacopeial articles.

Benoît

[Malcolm Needs ☆]

Yep, I wouldn't argue with that Benoit, except to say, annually is fine, unless the equipment goes wrong, or is modified in any way whatsoever, which would also require a re-mapping.

[Old Timer]

regaridng dual sensors for top/bottom - Tempsys Checkpoint has a dual probe sensor with a long and a short wire probe. We have it in our lab. Works great and you can see both temperatures on the system at the same time.