Agriculture Reference
In-Depth Information
onto unprotected foodstuffs positioned below. For these
reasons, great care must be taken to ensure that all prod-
uct is removed from areas being cleaned. Differential air
pressures must cause air to move from clean to dirty
areas and not vice versa. Rinse hoses, even under low
pressure, must not be inserted into drains.
To secure a due diligence defence in the case of pros-
ecution, it would normally be necessary to show that a
properly designed cleaning schedule was in place and
was being followed. Under the new EU regulations, a
HACCP or similar approach is mandatory for the man-
agement of food safety and GHP is mandatory and will
be audited. These requirements are also clearly defined
in other industry food safety standards (BS EN ISO
22000: 2005; International Food Standard, 2007; British
Retail Consortium, 2011).
As mentioned earlier, cost pressures may encourage
the cleaners to combine or leave out individual steps in
the cleaning sequence. This should be avoided. Anyone
responsible for food industry hygiene, and in particular
in the methodology of cleaning, should have a clear
understanding of what methods are correct for the
cleaning of food plants and the dangers of incorrect or
inadequate cleaning procedures.
Water
Water collecting in hollows on the floor or in blocked
drain openings can quickly become highly contami-
nated. Splashes caused by people or vehicles going
through the puddles can directly contaminate surfaces
and raise local aerosols. Water used in washing the plant
may be stored in holding tanks feeding the pumps. These
may also become contaminated and, with warm water
driving off the chlorine reserve, the rinse water itself may
become a source of re-contamination.
People
Personnel are the biggest single source of contamination
risk in a plant, from dirty protective clothing, inadequate
hand washing, hair, jewellery, sneezes, coughs, cuts and
sores. All plant personnel must be trained in hygiene and
the proper clean protective work wear supplied. Hand-
washing facilities must be conveniently located close to
production stations and entrances. Bactericidal, non-
perfumed soaps must be supplied, together with alcohol-
based hand disinfectant in high-risk areas.
The cleaning sequence
The optimal sequence for general routine surface clean-
ing of a food plant is:
1
Gross clean/preparation
2
Pre-rinsing
3
Detergent application
4
Post-rinsing
5
Disinfection
6
Terminal rinsing
Some of these steps may sometimes be skipped or com-
bined (perhaps where the nature and quantity of the
soil is light or during brief intermediate cleaning in
production breaks), but for systematic daily cleaning, the
sequence is very important. We will now look at each
step in more detail.
Surfaces
Surfaces, which are inadequately cleaned, may re-con-
taminate entire pieces of equipment. For example, one
badly cleaned roller on an otherwise spotless conveyor
belt can, in one rotation of the belt, smear it with grease
and dirt. Similarly, cutting blades in saws, slicers, dicers,
etc. must be very effectively cleaned.
Gross clean/preparation
This is the step that is most often incorrectly carried out
or completely ignored. Food residue that is left on the
equipment, surfaces and floors has many negative effects
on the cleaning performance:
•
It protects surfaces and the bacteria on them from the
attack of the detergent.
•
It reacts with and consumes the detergent so that its
function is weakened or chemical wasted.
•
It holds bacteria (often at very high levels) which can
re-contaminate surfaces at a later stage in the cleaning,
especially during the rinsing stage.
•
It can directly re-contaminate surfaces with grease
and protein which can act as nutrient for micro-
organisms and as a barrier to disinfectant. This is par-
ticularly true on moving machinery such as conveyors.
Cleaning procedures
The previous sections on soil, substrate, detergents, equip-
ment, methods and re-contamination should demonstrate
that the cleaning of a meat plant is a complex job. Only
with systematic procedures can a consistently hygienic
plant be maintained. These procedures form part of the
cleaning schedule
, a working reference document that
defines standards, methods, frequencies and materials for
all cleaning and disinfecting operations in the plant. The
schedule should form part of the Quality Manual of the
plant and be available for consultation or inspection.
Simplified extracts of the schedule, employing pictograms,
may be used as wall charts for individual plant areas.
Hygiene service suppliers often assist in the preparation,
upkeep and training of the hygiene procedures.
