Why Temperature Mapping
1. Storage areas need to be environmentally mapped to protect product quality and customer safety
2. A comprehensive temperature mapping study will ensure that storage area is accurately monitored, properly maintained and in compliance with all the applicable regulations
3. To Demonstrate by way of documented evidence that the chosen storage area is suitable for the storage of temperature sensitive medicinal products
4. A mapping exercise of proposed storage area will ensure that the company will understand their storage area and identify any potential areas therein that may be unsuitable to storage medicines .
5. A mapping exercise will also inform as to where permanent thermometers should be located.
What regulations and requirement must you comply with
Before beginning to temperature mapping plan ensure that following requirements and constraints
1. calibration: The Calibration of temperature control device and temperature monitoring devices must be evaluated .Calibration must be within its validity, traceable to a NIST (National International Standard) and devices must be calibrated to three points based on the temperature range required for product storage.
2. Environmental range and set point: The environmental range needs to be specified in accordance with the range of the temperature -sensitive product stored in storage area, as specified in in the product specification. The set point can be fixed value or a variable value based on different seasons, external climate conditions, and time.
3. Source of Heating and Cooling Components:identify sources of temperature variability such as fans, windows , racks/shelves, close to the roof or external walls generators , vents and diffusers. Sensor located near sources of heating or cooling components may caused increased variability of monitoring data.
What are the risks with storage area?
When creating a mapping plan first step is to identify risks with storage area. This can be understand with below shown diagram a typical warehouse layout.
The following risks should be considered as part of the mapping plan:
- Total volume of space
- Air circulations
- Layouts of shelves and racks
- HVAC capacities
- Outside air temperature and humidity
- lights can be a source of heat. Goods placed on high racking in close proximity to a light may be at risk
- Goods stored on tall racking is likely to have a wide temperature variation from top to bottom
- Goods stored close to loading dock may be affected by drafts
- Develop the mapping strategy detailing the number of sensor to be used, type of loggers to be used, sensor locations and distribution, set point value , data to be generated , and reporting requirements
- Write mapping protocols, including Installation Qualification (IQ), Operational Qualification (OQ) and Performance Qualifications (PQ).
- When determining the sensor locations, it is important to document a rationale for choosing the locations ,as well as create a diagram that provide a visual map of the locations.
- With regards to determining the number of sensors there is no set formula. Guidelines suggest placing sensors uniformly throughout all three dimensions of the storage area. A rough estimate is that small area of 12m X 12m X 12m requires 15 sensors to cover the edge and middle of each dimensions, where the sensors are no more than 6m apart.
Typical Sensor Distribution: 15 sensors covering all horizontal and vertical planes in a typical three dimensional mapping of this type of warehouse configuration.
What Parameter will Measure
- If product is sensitive to relative humidity, it is necessary to mapped for relative humidity as well as temperature.
How to Mapping Perform
- The mapping equipment’s needs to set-up and initial mapping test performed.
- The sensors must be labelled, programmed and fixed into position as documented in qualification protocol.
- New environmentally controlled areas are initially mapped empty (i.e. without products). the purpose of this initial test is to build a temperature/humidity profile and to identify potential areas of unacceptable temperature and humidity for the product during normal loaded operation mapping.
- At the end of the study period, the devices are collected and the data is downloaded and consolidated for analysis
Temperature Recovery Study
This study uses the same number of sensors in the same locations as the mapping study and measurement interval of 1 minutes.
- Door opened & Door Closed study
- Power Off and Power On
What will the duration be?
- Temperature mapping study typically lengths are 24 ,48 or 72 hrs.
- When the empty study is complete and empty environmental profile determined, a normal loaded operating mapping is performed during extreme seasonal variation such as summer and winter.
How Frequently Will take readings
- Once every minutes or once every five minutes.
- The results of the mapping exercise must be analysed and compared against the acceptance criteria as defined in the qualification protocol
- From the data, the analyst can identify critical areas (hot and cold spots) where the stored product may potentially be exposed to unacceptable temperature and humidity conditions
- This may include making change to the HVAC system , re-positioning sensors, or re-locating shelves to a modified layout design
- depending’s on the alterations proposed, an additional mapping study may be necessary to identify the new environmental profile and consequently the correct locations of monitoring sensors
- The temperature mapping report must be simple and easy to understand . complicated reports tends to attract questions by auditors .
- The reports should include all the data collected during the study , showing data points of each sensor, along with maximum , minimum and acceptable range limits. it should also includes details of the testing and alterations if any, conclusions, and plans to conduct additional schedule mapping
- WHO technical Supplement . Temperature Mapping of Storage Areas
- ISPE Good Practice Guide- Cold Chain Management (2011)
- S. Pharmacopeia: Good Storage and Shipping Practices <1079> USP32-NF-27
- MHRA: Rules and Guidance for Pharmaceutical Manufactures and Distributors