Dairy Establishment Inspection Manual – Chapter 17 - Higher Heat Shorter Time (H.H.S.T.) Processing and Extended Shelf-Life (ESL) Dairy Products
1.17.02 Scheduled Process

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The scheduled process means all the conditions pertaining to the processing and packaging equipment, containers and products needed to achieve and maintain the required extended shelf-life under refrigerated storage conditions.

To achieve the required pasteurization of ESL products in HHST systems, the scheduled process must be designed to provide a thermal destruction of the target microorganism equivalent to that achieved by a process with a minimum lethality value F0=0.1.

(Note: It is recognized that F0 is associated with commercially sterile products targeting a 12 log reduction in Clostridium botulinum spores, it was, nevertheless, chosen in this case because it is the preferred method used by process authorities for calculating process kill as opposed to the use of pasteurization value (P), which is more complex as it deals with varying reference temperatures and z-values.) Scheduled Process

The scheduled process is developed and documented by a process authority that has scientific knowledge and experience in this field. The documentation required to validate the process covers the scientific basis for selecting certain specifications and requirements, calculations used to derive numerical values for the specifications, a review of applicable regulations and guidelines, and a descriptive commentary on what equipment and controls are being used and why. The numerous variations encountered in commercial production are to be accounted for in the process. Critical factors that may affect the achievement of pasteurization of the ESL product need to be included in the scheduled process.

Testing procedures and operator instructions are to be included in the process documentation.

Upon initial commissioning of the processing unit or after significant alterations have been made to the system or scheduled process, appropriate testing and shelf life studies (see Task must be used to confirm that the process is valid.

Any changes to an H.H.S.T. system must be assessed by the process authority as to the potential impact they will have on the system, so as to maintain the safety of the product. Operating Instructions

Detailed operating instructions are to be made available to the operator, to ensure that the process is operated according to the design of the scheduled process. These instructions must include procedures for monitoring critical factors during system pasteurization or sterilization at start-up, and during production, and what to do if the critical factor limits are not met (process deviation procedures).

A process deviation occurs whenever any process is less than the scheduled process or when critical factors are outside of specified limits. Critical Factor Adherence

The critical factors are those factors specified in the scheduled process as being necessary for the achievement of pasteurization of the ESL product. The inspector must review the scheduled process to see what critical factors were established. If during on-site observations, any of these critical factors are not within the limits documented in the scheduled process, this constitutes a process deviation and the product cannot be considered pasteurized ESL until process deviation procedures are completed. Critical Factor Records

The processing records must contain all the required information and indicate if the products were processed within the acceptable limits for the critical factors (no process deviations). Process deviations require detailed documentation in the plant's process control records and/or a separate file for follow up by the plant management to determine the cause and corrective action for the deviation and to ensure any compromised product is properly identified and handled to prevent distribution or sale.

Process deviation records must include date and time of the process deviation, amount of product involved, product quarantine and release of affected product, investigation into the cause of the process deviation (e.g. equipment breakdown, power failure, low temperature at outlet of holding tube), the action taken (e.g. line cleared, repairs performed, system re-pasteurized/re-sterilized) and review by appropriate company personnel.

Process control records are part of the critical factors records. This information must be recorded in ink to provide a permanent record. Since this information provides a processing record, it will assist the plant in tracking down quality and safety problems and help prevent recall of their products. All production records must be reviewed on a timely basis by a member of plant management. Any operator's notes concerning unusual occurrences must be evaluated by plant management to ensure that a critical process parameter was not violated (i.e. that an unusual occurrence was not in fact a process deviation requiring product quarantine).

1. All process control records for H.H.S.T. systems shall provide the following data on every chart (only the processing operation requires a 12 hour chart):

  1. Plant name and address or registration number;
  2. Date, shift and batch number where applicable;
  3. Recorder unit identification when more than one is used;
  4. Product type and amount of product processed (may be recorded in production records);
  5. Identification of sterilization/pasteurization cycles (e.g. indicate when water or product being run);
  6. Identification of C.I.P., Amini-wash (if used)
  7. Unusual occurrences and operator comments;
  8. Signature or initials of the operators;
  9. No overlapping of chart pen markings;

For the S.T.L.R.:

  1. Reading of the official indicating thermometer during processing. This reading must never be lower than the recording thermometer reading;
  2. Record of time the Flow Diversion Device (FDD) is in the forward flow position, as indicated by the event pen;
  3. Recording thermometer tracing;
  4. Set point tracing, when multiple set points are used,
  5. All of (1) above

For systems equipped with a Meter Based Timing System (MBTS);

  1. Synchronized time with S.T.L.R. chart;
  2. Record of time the flow alarm is activated, as indicated by an event pen;
  3. Flow rate tracing;
  4. All of (1) above

For the pressure differential controller-recorder:

  1. Synchronized time with S.T.L.R. chart; Electronic data collection, storage and reporting of pressure differentials, with or without hard copy printouts, may be acceptable provided the electronically generated records are readily available at the establishment for review by the regulatory agency and meet minimum criteria required for S.T.L.R. charts.
  2. Raw product or media side pressure tracing;
  3. Sterilized product side pressure tracing;
  4. In lieu of (b) and (c) above, the pressure differential recording between (b) and (c)
  5. All of (1) above

For the pressure limit recorder:

  1. Synchronized time with S.T.L.R. chart; Electronic data collection, storage and reporting of pressure limit in the holding tube, with or without hard copy printouts, may be acceptable provided the electronically generated records are readily available at the establishment for review by the regulatory agency and meet minimum criteria required for S.T.L.R. charts.
  2. Holding tube operation pressure;
  3. All of (1) above

For optional additional temperature recorders/controllers on the system:

  1. Synchronized time with S.T.L.R. chart:
  2. Recording thermometer tracing;
  3. All of (1) above; note especially the identification of pasteurization/sterilization cycles;

All pertinent processing records should be retained as part of the quality assurance program. These records will assist the plant and regulatory agencies to determine if these products were adequately pasteurized to meet the extended shelf-life. The time-frame for retention is as follows:

  1. A one year period minimum;
  2. As determined by the responsible regulatory agency; or
  3. Until the finished product has been consumed (if more than one year).
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