Temperature Mapping of Warehouses and Fridges

Companies needing to comply with good manufacturing practices and cold chain requirements require specialised expertise and cold chain monitoring equipment, which is all available at CoolPac. CoolPac has years of experience helping companies with cold chain qualification, cold chain compliance, and temperature monitoring for the pharmaceutical, biological and food manufacturing industries. Temperature mapping is one of the methods of ensuring GMP compliance.

Why Do Temperature Mapping?

Clause 3.19 of the PIC/S GMP guide says:

Storage areas should be designed or adapted to ensure good storage conditions. In particular, they should be clean and dry and maintained within acceptable temperature limits. Where special storage conditions are required (e.g. temperature, humidity) these should be provided, checked and monitored.

How to check and monitor the temperature is not specified in the guidelines, however other industry guidelines expand on this concept:

Large commercial refrigerators and walk-in cold rooms should be monitored with an electronic temperature-recording device that measures load temperature in one or more locations, depending on the size of the unit. Portable data-loggers that can be downloaded onto a computer may be used instead of a fixed device. Records should be checked daily. 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). Condensate from chillers should not be collected inside the unit.

All warehouses should be temperature mapped to determine the temperature distribution under extremes of external temperature. Mapping should be repeated every two to three years and after any significant modification to the premises, stock layout, or heating system.” (From the UK Guidance on Wholesale Distribution Practice.)

These voluntary guidelines are a useful starting point in understanding the expectations of regulatory bodies.

The Difference Between Temperature Mapping and Calibration

In general, cold storage facilities, fridges and warehouses that comply with GMP have constant thermal monitor and, depending on the sophistication of the system, the temperature in that location is tracked and recorded automatically. These thermal monitors should be regularly checked to ensure they are recording the correct temperature.  This is known as calibration. The fact remains that the temperature readings from those temperature data loggers, even if they are calibrated, are taken only in that specific location.

Temperature mapping on the other hand is quite different. It is the monitoring and recording of temperature at a specific point in time but at multiple vertical, horizontal and linear locations.

Temperature mapping collects the following information:

  • Temperature variation in a 3 dimensional space;
  • Temperature variation in one location across a time period;
  • Temperature variations around doors, air ducts and windows;
  • What happens to the temperature when there is a power failure and how long the temperature stays within the range.

Temperature Mapping Protocol

Temperature mapping protocols will ensure data is collected in a consistent way, enabling replication of the process and comparisons at another point in time.

The following protocols should be considered:

  • Calibration of temperature monitoring equipment before and after the temperature mapping;
  • Define normal conditions, e.g. average stock holding, average number of times doors are opened and closed;
  • Consider seasonal variations in temperature, e.g. summer conditions and winter conditions;
  • Ensure a consistent and sufficient number of data probes;
  • Document temperature data logger locations paying particular attention to where hot or cold spots could be;
  • Acceptable limits for temperature excursions – temperature variation over time;
  • Reporting requirements.

How Much Does GMP Compliance Cost?

Temperature mapping done internally can be costly, due to the need to purchase temperature data loggers. However, data loggers and a temperature mapping protocol for your specific warehouse can obtained cost-effectively from CoolPac. CoolPac can supply data loggers, advise on where to place them, calibrate the loggers before the exercise, map out the data collection points, download and analyse the temperature data, then produce a report giving recommendations for compliance.

Contact Lyn at CoolPac on 1300 266 555 to find out more.