When validating and calibrating pasteurization equipment, which timing is correct?

• A. All listed times.
• B. Only during commissioning.
• C. Only when process changes occur.
• D. Only after major maintenance.

Answer: (A)

In pasteurization, keeping measurement accuracy intact is essential because the safety target depends on exposing the product to a precise time–temperature combination. Validation and calibration aren’t one-and-done events; they establish and maintain the accuracy of timers, temperature sensors, and controllers so the process truly achieves the required lethality.

Doing this at commissioning sets the baseline, so you know what correct operation looks like from the start. If the process changes—such as a new product with different heat transfer characteristics or a change in flow or load—the system must be re-checked to ensure the dwell time and temperature still meet the spec. After major maintenance, sensors or control circuits can drift, so recalibration confirms readings and timings are still correct. Since each of these situations can alter how the system actually performs, validation and calibration should be performed at all of these times.

So, validating and calibrating across commissioning, process changes, and maintenance—covering all listed times—is the best approach.