Agriculture Reference
In-Depth Information
Central water
pump
Central
chemical stock
and pump
Wall-mounted satellites
to apply central and
local hygiene
chemicals
Figure 5.6
Demonstration room showing installations of hybrid central/satellite foam and rinse stations (Reproduced with permission
from Ecolab. © Ecolab).
Spray
Prior to the advent of foam cleaning technology, this
method was widely in use; however, it is now seldom
used for the application of detergents. Spray cleaning
uses a gun and/or lance linked to a pressurised water sys-
tem; hygiene chemical induction is via an injector. This
may be achieved using satellite foam and rinse equip-
ment, mobile equipment or more simply via a backpack
sprayer of diluted product. Using this method for clean-
ing is wasteful, it is difficult to see the application, it is
often repeated unnecessarily, and the hygiene chemical
runs off rapidly from vertical surfaces. It is slower and
inferior in performance to foam cleaning. Conversely, it
is the usual method of application for disinfectants,
though as discussed earlier disinfectants can be applied
as foams. The subtle difference in the case of disinfection
is that this application is routinely concerned with food
contact surfaces, it is a faster application than foaming
and dependent on area and equipment to be treated and
spraying via a satellite injector system or a backpack
sprayer can both provide efficient outcomes.
with aerosols (debris and water droplets). Fogging sys-
tems can be small portable devices or built-in automatic
central systems. Fogging is only worthwhile if the rest
of the hygiene programme is properly carried out.
The important parameters for effective fogging are the
matching of the volume of liquid being fogged to the vol-
ume of the room, the temperature, the relative humidity
and the rate of air change. Ideally, saturation of the air,
with very fine droplets (10-20 µm) which stay suspended
for a long time, gives the best results. Failure to create the
correct fog droplet size and volume can mean that only
the uppermost surfaces of the plant receive the disinfect-
ant as it rains down and the air itself may remain largely
unaffected.
Knife and cutting tool disinfection
during processing
The EU hygiene regulations have over many years
demanded that knives and cutting tools used in animal
slaughter/processing be disinfected in hot water at 82°C
(Council Directives, 64/433/EEC, 92/116/EEC, 95/68/
EEC). It has been known for some years that this method
has some significant drawbacks (SCVPH, 2001); some
are listed below:
•
The cost of producing the hot water
•
The maintenance of steriliser boxes, particularly of
heating elements
•
Low comfort of the operator
•
Creation of considerable volumes of water vapour and
associated condensate
Fogging
Aerial fogging uses compressed air or other equipment
to generate a fine mist of disinfectant solution, which
should hang in the air long enough to fill the room
volume before settling on walls and difficult-to-reach
surfaces. Fogging is primarily focused on complete sur-
face disinfection in a defined enclosed area, though it is
possible to reduce airborne micro-organisms associated
