distinguish between microbial and non-microbial ATP since high levels
of ATP, whatever the origin, will indicate inadequate cleaning and
disinfection (see Section 10.5.3).
Cleaning dry process areas presents an entirely different problem from
that discussed above. By their very nature these areas are inimical to
microbial growth due to the absence of water. To introduce moisture in
the name of hygiene could have exactly the opposite effect and give rise
to microbiological problems. Cleaning in dry process areas should
therefore be mechanical, using vacuum cleaners, wipes and brooms.
11.5 Codes of Good Manufacturing Practice
The features of control at source outlined above are often enshrined in
official regulations or codes of Good Manufacturing Practice (GMP).
GMP is defined as those procedures in a food-processing plant which
consistently yield products of acceptable microbiological quality suitably
monitored by laboratory and in-line tests. A code of GMP must define
details of the process that are necessary to achieve this goal such as times,
temperatures,etc., details of equipment, plant layout, disinfection (san-
itation) and hygiene practices and laboratory tests.
Codes of GMP have been produced by a variety of organizations
including national regulatory bodies, international organizations such as
the Codex Alimentarius Commission as well as trade associations and
professional bodies. They can be used by manufacturers as the basis for
producing good quality product but may also be used by inspectors from
regulatory bodies.
While they can be very useful, a frequent limitation is that in their
desire to be widely applicable they tend to be imprecise. This leads to the
use of phrases such as ‘appropriate cleaning procedures’, without spec-
ifying what these may be; ‘cleaning as frequently as possible’, without
specifying a required frequency; ‘undesirable organisms’, without spec-
ifying which organisms. They also often fail to identify which are the
most important requirements affecting food quality and which are of
lesser importance. As a result, someone conducting, supervising or
inspecting an operation is left uncertain as to what specifically is required
to ensure that the operation is conducted in compliance with GMP.
This sort of information is often only available based on a detailed
analysis of an individual processing operation.
11.6 THE HAZARD ANALYSIS AND CRITICAL CONTROL
POINT (HACCP) CONCEPT
In the food industry today approaches based on Good Manufacturing
Practice are being largely superseded by application of the Hazard
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