Temperature mapping involves measuring the temperature at various points in a storage or transportation system to identify any hot and cold spots or areas with higher humidity. The parameters that temperature and humidity must fall within are predetermined by regulating bodies and/or the specific piece of equipment. 

Applicable to (but not limited to) cold storage room, stability chambers, refrigerators, incubators, warehouse(s), in-process material storage areas, manufacturing area, packaging areas, control (reserve) sample storage area at manufacturing site.

PROCEDURE

Mapping study:

•  For material storage area where temperature control is required, at least 2 (two) mapping study to be performed in order to observe the effect of seasonal variation. That is one during warmest season and one during the coldest season that will establish whether the equipment and devices installed in the area is able to maintain temperature as per the requirement throughout the year even during extreme weather conditions.

• For material storage area where temperature and relative humidity is required mapping study to be performed in 3 (three) seasons in order to observe the effect of seasonal variation. That is one during warmest season, one during monsoon season and one during the coldest season that will establish whether the equipment and devices installed in the area is able to maintain temperature and relative humidity throughout the year even during extreme weather conditions.

• Seasonal mapping to be performed as per the prevailing condition of the area such as available material, personnel or machinery.

• While qualifying storage area, mapping study to be performed considering empty and optimally loaded conditions.

• Prior to mapping study, ensure that all the probes or data loggers are within its calibration period. There should be an international recognized standard traceable to 3 point calibration with guaranteed error of not more than ± 0.5°C at each calibration point. Reference of same shall be verified and attached along with the report.

• Temperature recording probes should have an accuracy of at least ± 1°C and relative humidity recording probes should have an accuracy of at least ± 3%.

• Depending on the size of the area, number of probe or data logger locations and placement shall be determined. Rational for number of probes and its placement to be included in the protocol. Probe placement rational may include (but not limited to):

• Temperature or relative humidity probes or data logger should be arranged in a grid form along the width and length of the area so that area is reasonably covered with probes or data logger locations every 5 – 10 meters. The selected probe or data logger grid should take account of: 

1.  Layout of the area (e.g. whether it is square or includes compartment).

2.  The extent to which shelving and products may affect airflow.

3.  Suspected cool or warm areas such as near the control sensors and monitoring sensors.

4.  If the ceiling height is 3.6 meters or less, arrange probes or data loggers directly above one another at high and low level (e.g. one data logger at floor level, one data logger at 1.2 meters and one data logger at 3.0 meters).

5. If the ceiling height is greater than 3.6 meters, arrange probes or data loggers in vertical arrays at the bottom, middle and top of the space. For storage area of 6 (six) meters in height, 3 (three) probes or data loggers should be placed in each grid location heights of 1.8 meters, 3.6 meters and 5.4 meters.

• To eliminate the possible errors and assure consistent execution, following care should be taken.

1. Assign each probes or data logger’s location a unique identification number.

2. Label the exact spot where the data logger should be placed by the sensor’s location name.

3. Create a physical map or photograph with all data logger marked by name.

4.  While placing the sensors, consider shelving or pallet racking that may have an effect on the distribution of temperature and humidity and the same to be part of the protocol.   

• Areas that are vulnerable for variations in temperature and humidity due to seasonal conditions, mapping study to be carried out for 7 (seven) consecutive days with data recording interval of 15 minutes or below.

• For temperature-controlled equipment that is not critically affected by seasonal variations in temperature (e.g. Freezer rooms, cold storage rooms, stability chamber and incubator), mapping study should be performed with 24 to 72 hours.

•  Following information’s (but not limited to) should be part of the mapping study report:

1. Unique ID, make and model no. of the probes or data loggers.

2. Calibration traceability of the probes or data loggers.

3. Graphical data representation.

4. Diagram showing high and low points and point of highest fluctuation.

5. External agency personnel training certificate performing the mapping study.

6. Mean kinetic temperature (MKT) can be applied to each of the separate area being monitored.

Re-mapping study:

• Re-mapping study to be carried out in below mentioned cases:

• Periodic re-mapping as per schedule for temperature/relative humidity re-mapping frequency.

• Significant modifications in area equipment.

•  Re–mapping study to be performed as per the prevailing condition of the area such as available material, personnel or machineries.

•  Re–mapping study to be performed for at least three (3) consecutive days with data recording interval of 15 minutes or below.

•  For material storage area, where temperature is being monitored, re-mapping to be performed in summer season.

•  For material storage area where temperature control is required, re-mapping to be performed in summer season.

•  For material storage area where temperature and relative humidity is required, re-mapping study to be performed in summer and monsoon season.

• Officer or designee – Maintenance shall prepare and maintain the re-mapping schedule as per frequency for temperature/relative humidity re-mapping frequency.

• If the mapping or re-mapping study indicates undesirable conditions, the same shall be investigated and appropriate corrective measures to be taken as below(but not limited to):

1. Removing product from the area.

2. Changing work practices (such as keeping doors open or closed).

3. Changing racking or shelving configurations to improve air circulation.

4. Changing the location of heating devices.

5. Adding air conditioning systems.

6. Improve ventilation.

7. Installing more or large capacity HVAC system.

8. Adding humidification or de-humidification.

9. Installing an HVAC control system.

10. Up gradation or repairing of system.

• After completion of mapping study and evaluation of data, routine monitoring to be performed from following locations:

1. Locations with maximum temperature and relative humidity.

2. Location with highest fluctuation for temperature and humidity.

3. Highest temperature observed at manufacturing area.

4. Any other location as deemed necessary.

5. For semi finished area, location with maximum temperature and maximum relative humidity shall be considered for monitoring during routine process.

6. If identified worst case location is not feasible (such as center of the room, nearby process equipment), next identified worst case location should be considered with adequate justification for routine monitoring.

• Site QA shall maintain the statement of mapping studies performed for various areas along with its dates in an excel spreadsheet.

• In case temperature and relative humidity goes out of limit during daily monitoring with data logger:

1. 1. 1. 1. Inform to maintenance department for the out of limit condition, by using maintenance breakdown form.

         2. If rectification requires more than 8 (eight) hours, inform to user department and QA for impact assessment on stored product/material.

         3. Based on conclusion of investigation, further necessary action should initiate.   

         4. Record the remark on the respective temperature/relative humidity record.

• In case data logger fails during daily monitoring:

1. Inform to maintenance department by using maintenance breakdown form .

2. User should place the calibrated thermometer / hygrometer at location with maximum temperature and high fluctuation temperature/relative humidity to monitor, till the rectification of data logger problem.

3. Record the temperature /relative humidity thrice in a day (one reading should be between 12:00 hrs and 17:00 hrs).

4. After rectification of data logger failure, thermometer/hygrometer should be removed.

5. In case, the printout facility is disturb for more than 1(one) hour, user department to inform maintenance department by using maintenance breakdown form .

REFERENCES

Temperature mapping of storage areas (Technical supplement to WHO Technical Report Series No. 961, 2011), January 2014.

RECORDS

• Schedule for temperature/relative humidity mapping study.

• Temperature/Relative humidity Mapping Protocol.

• Temperature/Relative humidity Mapping Report.

• Temperature/Relative humidity Re-mapping Protocol.

• Temperature/Relative humidity Re-mapping Report.