those which are not,e.g.sugar, vinegar,etc. The use of quantitative tools
such as predictive models to calculate the potential for growth or the
extent of survival at each step can also provide the hazard analysis with
valuable information.
11.6.2 Identification of Critical Control Points (CCPs)
Once the hazard analysis has produced a list of the potential hazards,
where they could occur, and measures that would control them, critical
control points (CCPs) are identified. A CCP is defined as a location, step
or procedure at which some degree of control can be exercised over a
microbial hazard; that is, the hazard can be either prevented, eliminated,
or reduced to acceptable levels. Loss of control at a CCP would result in
an unacceptable risk to the consumer or product.
A raw material could be a CCP if it is likely to contain a microbial
hazard and subsequent processing, including correct consumer use, will
not guarantee its control. Specific processing steps such as cooking,
chilling, freezing, or some feature of formulation may be CCPs, as could
aspects of plant layout, cleaning and disinfection procedures, or em-
ployee hygiene. Many are self-evident, but decision trees can be used to
help in their identification (Figure 11.10).
The questions in the decision tree should be asked for each hazard at
each step in the process. Though it is necessary to consider hazards
individually it will emerge that some points in a process are CCPs for
more than one hazard. For example, using the decision tree, pasteuriza-
tion will be a critical control point for VTEC, L. monocytogenes,
SalmonellaandCampylobacterin the processing of milk. Though chill
storage of the milk prior to pasteurization is clearly beneficial, since it
will reduce or prevent the growth of these and other organisms, it will not
be a CCP for these particular hazards since they are eliminated by
subsequent pasteurization. Chilling would, however, be a CCP with
regard toStaph. aureusbecause by preventing growth of the organism, it
will prevent production of heat resistant toxin that could survive pas-
teurization.
If a hazard is identified at a step where control is necessary for
safety, and there is no control measure at that or any subsequent step,
then the product or process should be modified to include a control
measure.
11.6.3 Establishment of CCP Critical Limits
For each of the CCPs identified, criteria must be specified that will
indicate that the process is under control at that point. These will usually
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