Thermal Process Deviation in Refrigerated Soup: Hold, Release, and Corrective Action
A food manufacturer produces refrigerated ready-to-eat soup in 2,000-case batches. The food safety plan identifies a continuous thermal process with a critical limit of 90°C for 30 seconds to control vegetative pathogens. The process is monitored by a chart recorder; the operator verifies the recorder reading every 15 minutes. On March 3, batch 03-07 experienced a temperature drop to 86°C for 4 minutes. The operator noted the drop but did not stop the line because the hourly average was 91°C. The batch was filled and placed on hold. The QC supervisor reviewed the chart the next day and released the batch, writing 'minor deviation, average met.' The chart recorder was last calibrated 11 months ago; annual calibration is due. The firm has no written corrective action procedure for thermal deviations.
1. Was the 86°C excursion a deviation from a critical limit? What immediate actions and product disposition decision are required?
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Yes. The critical limit is 90°C for 30 seconds; 86°C for 4 minutes is a deviation. The product is potentially adulterated because the scheduled process was not met. The 'hourly average' is not the critical limit; averaging can hide a lethal-process failure.
Immediate actions:
- Stop the line and segregate batch 03-07.
- Place the batch on hold under a documented hold/release procedure.
- Notify the PCQI and plant management.
- Begin a corrective action investigation.
Do not release the batch based on the supervisor's 'minor' determination. Disposition options include reprocessing with a validated process, using the product in a way that receives a validated kill step, or destroying it. Any rework or reprocessing must be validated for the target pathogen and must not create a new hazard. The firm must also determine whether other batches produced since the last calibration or during the same period were affected. Records of the deviation, investigation, disposition, and verification are required.
2. Evaluate the monitoring and verification program. Is a 15-minute operator check adequate with continuous recording? What about the calibration status?
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Continuous recording plus a 15-minute operator check can be an acceptable monitoring design if the recorder is calibrated and the checks confirm that the recorder is functioning. The continuous chart is the monitoring record for the critical limit; the operator check is a verification of the monitoring device, not a substitute for the critical limit.
The calibration is a serious problem: it is 11 months overdue, so the accuracy of the chart is not verified. That does not automatically mean all product is unsafe, but it expands the investigation to all product made since the last valid calibration. The firm should calibrate the recorder, review the calibration history, and assess whether drift could have affected other batches.
The supervisor's release also shows that monitoring records were not reviewed by a qualified person with authority to hold product. Verification should include a timely review of records, a documented calibration schedule, and a check that corrective actions were effective.
3. Draft the corrective action and verification steps, including records. Does this trigger reanalysis?
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The corrective action procedure must be written and must include:
- Identifying the deviation and affected product.
- Segregating and holding product.
- Determining root cause-for example, steam supply, flow rate, recorder failure, or operator error.
- Evaluating product disposition with a qualified individual.
- Correcting the cause and preventing recurrence.
- Verifying that the corrective action was implemented and effective.
- Retaining records.
Verification should include review of the corrective action record, a check of subsequent batches, and confirmation that the recorder is calibrated and functioning.
A deviation like this requires a reassessment of the food safety plan if it shows that the thermal process or monitoring system is not adequate. At minimum, the firm should evaluate whether the critical limit, monitoring frequency, and recorder maintenance remain valid. Reanalysis is required when there is a significant change or when the preventive control is not effective. The firm should also train operators to stop the line and hold product when a critical limit is not met.