The Facts and Considerations of Temperature Mapping

Image Credit: Ellab

Temperature mapping is the process of determining the temperature profile of a temperature-controlled environment or process. This can include, for example, refrigerators, freezers, incubators, stability chambers, warehouses or autoclaves. The profile is calculated by measuring multiple points in a defined area throughout a specified study interval.

Temperature mapping aims to establish the variance between each point of measurement, or fluctuation within a defined area over time. To ensure safety, and that the data adheres to the required tolerances, the data must be analyzed in each of these controlled temperature units (CTU) or processes.

For controlled temperature units, environmental chambers, storage areas, and cold chain activities such as transportation and logistics centers, product safety means being stored in meticulous conditions within its defined tolerances.

For processes such as autoclaves, depyrogenation ovens, Steam-In-Place installations, ovens, controlled rate freezer, lyophilizers or retorts, safety means being able to hold a certain temperature for a specific duration to achieve a specific task such as sterilization.

Why Conduct Temperature Mapping?

Temperature mapping is imperative for companies that are involved in highly regulated environments, such as food, hospital, pharma, medical device, biotech, etc. It can also be required as part of accreditation processes such as CAP.

At the very least, these regulated companies should adhere to the FDA and the GXP (GMP, GLP) guidelines for the production, transportation and storage conditions, which is valued internationally. Under these circumstances, it is crucial to find a trustworthy partner to conduct GXP mapping services.

Temperature mapping is vital irrespective of how well constructed a storage area is, or a process is designed, as there will be temperature fluctuations that will affect the items being stored or processed. Controlled products such as food, medical devices and drugs are frequently subject to a greater degree of control and testing.

The amount of testing, documentation and frequency of temperature mapping boils down to the individual company performing their risk assessment, which may incorporate variables such as product sensitivity to the temperature fluctuations, effect on product and impact on patients. 

Image Credit: Ellab

When Should Temperature Mapping be Performed?

New Equipment

Following the installation of a new piece of vital equipment, a standard-qualification process is begun. Instruments such as autoclaves receive a qualification at first, but frequently need to be qualified specifically to how they will be used for certain loads and cycles.

Repaired Equipment

When a unit is repaired, it is normally tested to ensure that its performance matches expectations.

Relocated Equipment

Moving of a unit may frequently have a notable impact on the unit’s performance, which is why a requalification may be required.

Periodic Continuous or Re-Qualification

For autoclaves and other sterilization instruments, a re-qualification cycle of once a year is typical. The frequency can vary from once a year, or less, to as great as five years for storage areas such as reach-ins, walk-ins and warehouses.

Testing Storage Areas based on the Impact of External Environmental Conditions

A storage area such as a warehouse can be highly affected by the building’s external temperature. This is especially true in extreme seasons such as summer and winter, ultimately resulting in storage areas that ought to be tested seasonally.

Image Credit: Ellab

Image Credit: Ellab

How is Temperature Mapping Performed?

Step 1 - Identify Relevant SOPs and Protocols

The first step in the temperature mapping process is to create the required documentation. A procedure or protocol is often leveraged to provide a framework for the testing process. This test document may contain performance qualification, operational qualification, continuous qualification/requalification, engineering studies, a factory acceptance test and a site acceptance test.

This formal process includes information such as the duration, quantity and placement of temperature sensors. It is also comprised of the conditions the test will be performed under such as empty, loaded or minimum/maximum conditions.

Further testing may be conducted depending on the specific unit being tested. Storage areas may have more tests performed, such as open door, power interruption, power loss mapping and unconditioned load studies. Warehouses may need further tests season to season.

Step 2 - Execute and Document Test Scripts

The next step is to execute and perform those test scripts in a qualifying style while using good documentation practices to record the results. To ensure a project is successful when the temperature mapping is executed, the capability of the staff, type and amount of temperature mapping equipment and availability of the units under test (UUT) must be kept under consideration.

Step 3 - Reporting the Findings

Finally, after the data has been analyzed, the report package must be completed. The qualification or validation report package is a compilation of the executed procedures or protocols together with all the test data that corroborate the results. This includes a summary report for easy review.

What Types of Equipment Require Temperature Mapping?

Reach-in and walk-in controlled temperature units (CTU) and controlled environmental units (CTE) such as:

• Refrigerators
• Freezers
• Stability chambers
• Incubators

Conducting temperature mapping for these units makes sure that every point within the outlined storage area confidently meets acceptance criteria. The temperature mapping is performed over a duration of time to guarantee that, as the systems actuate, the temperature is constantly within limits.

Warehouse Temperature Mapping

Warehouse qualifications that include temperature mapping hinge on the number of sensors and strategic planning for their distribution within the storage area. Each warehouse qualification will need a custom number of sensors for temperature mapping based on the characteristics of the individual warehouse.

A few of the variables include the width, height, length, external-facing walls with direct sunlight, racking layout, insulation, HVAC air inlets/outlets, fans, openings such as doors and overhead doors as well as the changes in outside (ambient) season temperatures. All these factors will have an impact on the consistency of the temperature inside the warehouses and must be taken into account when making the temperature mapping plan.

Temperature Mapping/Heat Distribution of Autoclaves (Steam Sterilizer) and Depyrogenation Ovens (Hot Air Sterilizer)

For several applications in regulated industries, there is a need to sterilize a range of items to guarantee safety. Two typical methods of sterilizing are moist heat steam sterilization and dry heat sterilization, often known as depyrogenation.

Steam sterilization can be utilized for a wide variety of items, including growth media, glassware, antifoam, waste, unwrapped goods, etc., whereas depyrogenation is frequently used for items that can manage higher temperatures such as glass vials, syringes, staples, orthopedic components and surgical rods. Each of these processes needs specific qualifications depending on the kind of items and materials being sterilized. Ultimately, the overall concept and qualification process can be quite alike.

What Types of Validation Equipment are Used for Temperature Mapping?

Data Logger Temperature Mapping System

Things to keep in mind when selecting data loggers are the storage memory capacity, sampling rate, temperature accuracy, temperature range, physical size, internal vs. external sensor, transmitting vs. non-transmitting and battery life.

Thermocouple Temperature Mapping System

This solution requires a base unit that the thermocouples can connect to in order to gather data and conduct a variety of analyses. The kind and quality of thermocouples will influence the accuracy. Depending on the temperature being mapped, the precision of the thermocouples will increase or decrease.

Temperature Mapping Considerations

What to Look for When Choosing a Temperature Mapping Contractor

It can sometimes be hard to decide who provides the best type of services for a specific facility. When choosing a temperature mapping contractor, some key points should be considered:

• Quality of the staff and engineers
• Quality of the equipment used to conduct temperature mapping
• Time spent preparing and performing measurements
• Reputation in the industry as temperature mapping equipment manufacturers
• Quality and turnaround of the documentation upon completion

What Ellab Offers

• A full-service turn-key solution by supplying equipment, writing protocols, providing engineers and completing summary report packages
• Temperature mapping equipment through either purchase or rental solutions
• A customizable approach to meet your requirements
• Staffing for either projects or full-time staff augmentations

Image Credit: Ellab

This information has been sourced, reviewed and adapted from materials provided by Ellab.

For more information on this source, please visit Ellab.