Download Cleaning and sanitation

Cleaning sanitation and pest control
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© NSW DET 2007
Contents
Overview
3
The importance of pest control
4
Types of pests
6
Stored product pests
14
Cleaning and sanitation
18
Requirements for cleaning
18
Water
18
Detergent
19
Sanitizing
23
Cleaning and sanitizing programs
General cleaning method
27
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Summary
32
Glossary – Pest control
33
Glossary – Cleaning and sanitation
34
Answers to activities
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Overview
Food handlers need to be familiar with the requirements for pest control and
effective cleaning and sanitation to ensure that food safety hazards are
controlled.
In this topic, you will learn how to:
 prevent and minimise potential health risks caused by the pathogens
they harbour
 reduce damage, loss and wastage due to contamination caused by
pests
 avoid prosecution because of the presence of pests on your premises
 maintain your customer satisfaction.
Also, remember that good cleaning is important because it:
 extends the storage life of raw and processed products
 reduces the risk of the product being involved in outbreaks of food
poisoning
 reduces the number of product rejections, returns and complaints
 reduces maintenance costs and lost time through breakdowns by
regular dismantling and checking of equipment
 reduces the environmental contamination with micro-organisms
 improves working conditions and encourages better hygienic practices
by employees.
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The importance of pest control
We refer to these pests as vermin and they should be eliminated from the
food premises. They generally inhabit unsanitary environments such as
toilets, garbage areas, drains, sewers and any unseen, inaccessible places.
Because of these surroundings, vermin will pick up dirt and potentially
dangerous micro-organisms (pathogens).
This contamination can then be transferred to the food handler, food or
surfaces and utensils used in food preparation. Such contamination increases
the potential for transmission of disease and food poisoning.
Why control pests? There are many reasons for ensuring that food premises
are kept free of vermin.
The main reasons are summarised below:

To prevent or minimise the potential health risk: flies, cockroaches,
rats and mice are known to carry and spread many illnesses and
diseases such as polio, typhoid, dysentery, diphtheria and food
poisoning.

To reduce damage and loss due to wastage: contamination
(infestation) with these vermin causes widespread damage.

Effective pest control will help to maintain the financial viability of
food businesses.
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Activity 1
How many hygiene problems can you find in the illustration below? Write your list under
the illustration.
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Check your feedback at the end of this topic.
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Types of pests
There are many types of pests that may cause problems in food premises, for
example:
 cockroaches
 flies
 rodents (rats and mice)
 weevils, beetles, moths and other insects.
The last category of pests is sometimes referred to as stored product pests.
Although they don’t generally pose a health risk, they are still unacceptable
in food and food premises.
How to control pests
The following are the main points to remember regarding pest control:

Good hygiene and sanitation in well-maintained food premises will
go a long way in limiting the number of pests.

Prevention of entry by use of effective screens, vermin proofing,
design and construction of premises will reduce pest problems.

Regular treatment and maintenance of pest control programs, and
quick action to eliminate infestations if detected, are also advisable.
In other words:
 don’t feed pests
 don’t provide shelter for pests
 destroy pests.
Only by implementing the above practices will food handlers be able to
control undesirable pest problems.
Cockroaches
Cockroaches are probably one of the worst problems for business. Not only
do they eat the food and not pay their bill, but they leave all sorts of nasty
little surprise packets behind. Their presence also excites the local food
safety officer/auditor into a state of persecution frenzy, which can also cause
you big bucks in fines and more lost business!
Some very ill-informed people say that cockroaches are not dirty. This could
not be further from the truth. Like most other vermin, they frequent and
inhabit very unclean and unsanitary environments. You find them living in
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drains (including sewers), garbage areas, behind and underneath dirty, dusty
and greasy ovens, fridges, sinks, and the like.
Their bodies will pick up disease-carrying micro-organisms from these
environments. They are not fussy about what they eat and will happily eat
any contaminated, rotten old food or anything else that provides them with
nutrients (and there is plenty of goodness in the waste flushed down the
sewer—it makes a great fertiliser).
These dirty little creatures will then walk all over your preparation benches,
shelves and utensils, scattering dirt and disease all over the place as they go.
They also have another particularly nasty party trick they save for any food
you may have left out: they do not have a very well developed digestive
system. In order to fully break down their food, they regurgitate their food
then re-eat it.
They may perform this little act on some food you left out on the kitchen
bench. And if vomiting over food is not bad enough, just think about the
consequences if they had been previously dining on some dirty great big
piece of waste down the sewer!
If you require further convincing, have a look at colour print numbers 1 and
47.
Types of cockroaches
Although many species of cockroaches exist, only a few varieties cause
problems. Below are details of the main cockroaches infesting food
premises.
Types of cockroaches
Preferred habitats
German cockroach (Blatella germanica)
This cockroach prefers warm, dry places
with ready access to water, such as
kitchen cabinets and inside the back of
refrigerators. An excellent climber, it is
often found above ground level. It is
rarely found outdoors. Although it is
small it is the most common and
persistent pest in food handling premises.
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American cockroach (Periplaneta americana)
American cockroaches prefer warm,
damp places such as sewers, wood piles
and garbage bins. This is the largest and
best-known cockroach.
Smoky-brown cockroach (Periplaneta
fuliginosa)
Smoky-brown cockroaches prefer a
warm, humid climate. They frequently
invade buildings from gardens, through
doors, windows or other entrance points.
Australian cockroach
This cockroach is similar to the
American cockroach, though smaller.
Brown-banded cockroach
This cockroach is similar to the German
cockroach, but likely to be found
in all parts of a building.
Figure 1: Types of cockroaches
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The life cycle of cockroaches
Cockroaches are good survivors and very rapid breeders. After mating, the
adult female produces an egg case in which dozens of cockroaches develop.
The egg capsule is either carried by the female or deposited, generally near a
food source. If carried, as with the German cockroach, the capsule may be
seen projecting from the abdomen. The egg case is small (approx 5–10 mm),
oval, capsule-like and glossy.
The baby cockroaches, known as nymphs, hatch out of the egg case after a
few weeks (depending on temperature). They continue to grow through a
series of moultings over a period of months until they reach maturity and
repeat this life cycle.
Figure 2: Life cycle of a cockroach
Control of cockroaches
Good hygiene and sanitation is the first line of defence to reduce infestations
of cockroaches. Floors, walls, and so on should be kept free of cracks and
gaps to deny cockroaches access and hiding places. Carelessness and
uncleanliness provide these insects with food.
Eradicating cockroaches
There is a wide range of methods available to eradicate cockroaches:

While making premises less attractive to cockroaches through lack of
food and shelter is the most effective approach, usually a few
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cockroaches will enter somehow and find food and shelter. The use of
poisons to eradicate or exterminate them may be necessary.

Spraying aerosols is a waste of money for cockroach control unless
sprayed directly onto the insect. Aerosols will not penetrate places
where cockroaches usually shelter.

Spraying surface sprays near areas cockroaches may inhabit is usually
the most effective method. Spray these near cracks and crevices, around
fridge motors, under sinks and other enclosed areas. Dusts may
sometimes penetrate enclosed areas more effectively. Don’t apply any
insecticide to areas which may come in contact with food. Surface
sprays and dusts are usually based on organophosphate insecticides.

Sticky traps can tell you if there is a problem, but are unlikely to control
a serious infestation. Baits may be effective if all other available food is
removed.

The use of professional pest controllers is recommended since they are
best qualified to bring the situation under control. The use of residual
surface sprays, specifically for cockroaches, is recommended to get the
best results.

Fumigation can be effective but is expensive and inconvenient; this must
only be undertaken by professional pest controllers. And remember, any
extermination method can only kill pests—it cannot prevent more pests
entering and staying.

The use of insect growth regulators is another method of controlling
insects, including cockroaches. These chemicals prevent the
development and breeding of the insect.
Activity 2
1
What are the main indicators of pest and hygiene problems?
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2
Do you think these indicators are a problem for commercial food premises?
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Check your answers with the feedback at the end of this topic.
Flies
Flies feed on both rotting material and foodstuffs and carry micro-organisms
from one to the other, either on their feet or on their hairy legs. They feed by
vomiting onto foodstuffs then sucking up the liquid food.
The life cycle of flies
The common house fly breeds in decaying matter and manure. The female
lays batches of eggs that hatch into tiny white legless larvae (maggots) in 8
to 36 hours. When fully grown, a larva migrates to a drier, cooler site where
a pupa is formed. Within a few days the adult fly emerges. It has a life
expectancy of one to three months depending on weather and temperature.
Figure 3: Life cycle of the common house fly
The life cycle of other flies which present problems in different areas, such
as the fruit, ferment or vinegar fly (Drosophila species), the bush fly (Musca
vetustissina), and buffalo fly, are similar to that of the house fly. Blowflies
are common in country areas and are generally carrion eaters. Their life
cycle is similar except that some varieties may deposit larvae directly onto
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foodstuffs and there is no egg stage. Generally speaking, blowflies enter
premises accidentally and spend most of their time trying to get out again.
Control of flies
Listed here are several ways to prevent flies from entering premises.

Suitably screening all openings will keep flies outside.

Air curtains are effective in doorways where traffic may be heavy.

Strict hygiene will reduce the attraction of the flies to a potential
food supply.
Eradicating flies
There are two popular ways to eradicate flies:

Electrical fly traps work on the principle of attracting the flies—and
other insects—to a ‘blue’ light through an electrical grid. They are then
electrocuted when they touch the grid.

‘Knock down’, quick killing insecticides can be effective. These usually
contain synthetic or natural pyrethrins which have a low toxicity as well
as being fast acting. All food must be removed or covered before
insecticides are used and the premises must be thoroughly cleaned
before re-use.
Rodents
Rodents such as rats and mice also present a major problem to the food
industry. Rodents are known carriers of a number of diseases and food
poisoning micro-organisms. Because of their feeding habits, they carry
bacteria from rubbish, sewers and other dirty sites to food establishments,
and food if it is left out. They will also leave their droppings (faeces) and
because of poor bladder control, will urinate over benches and anything
(including food) they travel over!
Signs of rodent infestation are usually damage to food or packaging, or
finding droppings. These are very dark and the size is about twice as large
as a grain of rice in the case of rats and about the same size as a grain of rice
in the case of mice.
The main rodents that cause problems are house mice, as well as the brown
rat and the smaller black rat.
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Figure 4: The common rat—Rattus rattus
The life cycle of rodents
Rodents are prolific breeders and, if conditions are suitable, population
explosions are common. The average litter is about six and normally at least
six litters can be expected each year.
Control of rodents
It is much easier to prevent rodents from entering premises than to get rid of
them.
Prevention
Buildings should be constructed so that all entrances are properly sealed.
Within the building, fittings should be constructed so they don’t offer any
hiding places. Good lighting and proper ventilation will also discourage
rodents.
Rubbish, which is a potential hiding or nesting place, should not be allowed
to accumulate. Rats are capable of foraging for food over a fairly wide area.
Mice rarely move more than a few metres from their nesting site once this is
established, because they dislike moving across open areas.
Good hygiene procedures will discourage rodents. Food scraps should be
removed and placed in sealed containers. All food should be stored in
containers, about 45 centimetres above the floor.
Eradicating rodents
The following steps will help to eradicate rodents:

Clean out premises to minimise hiding places.

Remove rubbish from around the premises.
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
If only small numbers are involved then a trapping program could be
effective. The type of trap and the bait used will depend on the rodents
present and the type of food they appear to favour. For example, if
rodents have been feeding on meat scraps and fats, cheese may not be
attractive to them. Rats are generally wary of traps unless they have
been set out for three or four days without bait.

Poisons are commonly used where the numbers are large or potentially
large. Poisons can be divided into two main categories—acute and
chronic.
Acute poisons are available but most are non-specific and accidental
poisonings of domestic pets and people have occurred. Their use should
be carefully controlled by a skilled operator and they should not be used
near food.
Chronic poisons are now commonly used and are very effective. Anticoagulants can be used by unskilled operators. It is usually necessary
for the poison to be taken up over a period of three to seven days before
it is effective. It will completely eradicate a heavy infestation in one to
two weeks. Accidental consumption on one or two occasions is not
necessarily serious.
The poisons (rodenticides) are usually prepared as a wet or dry bait.
The baits consist of cereal, vegetable or flour and melted fat, and are
coloured a distinctive blue or green. The baits are placed in a bait box
which is clearly marked ‘Rodent bait’ and closed on all sides, with
openings only large enough to allow rodents to enter. Spillage of
rodenticide must be avoided.
Care should be taken in the storage and usage of poisons. They should
be packed in distinctive containers and be properly labelled.

Fumigation is perhaps a last resort and should only be attempted by
skilled operators. The gases used are highly poisonous to humans and it
is necessary to get approval from the NSW Health Commission before
use. Fumigation cannot be used in premises where meat is stored.
Colour print numbers 4 and 48–50 show various problems with rodents.
Stored product pests
There is another category of insects which also cause great problems to the
food handler, known as stored product pests. These do not generally present
a direct health risk. However, they are of great concern since food
contaminated or infested with stored product pests, such as weevils, moths
and beetles, are considered to be spoiled and unfit for human consumption.
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Foods affected
Many foods can become infested, but some particular favourites are
mentioned below:
 Grain products such as wheat, rice and corn are quite often attacked by
beetles or weevils.
 Flour and cereal-based products such as pasta, breakfast cereal, cake
mixes and dried food mixes are favoured not only by beetles, but moths
will also set up home in them.
 Many other foods, particularly dried and semi-dried foods, are also
attacked by stored product pests. Some of these foods are:
 chocolate
 dried vegetables
 dried fruits such as apricots and sultanas
 spices and dried herbs
 packet foods, soup mixes, sugar, tea and nuts.
Types of stored product pests
There are many stored product pests, such as moths, beetles and weevils.
Beetles and weevils
Figure 5: Flour beetle and rice weevil
Weevils and beetles are among the most destructive of the stored product
pests. Even though they are small (2–5 mm), their strong jaws can easily
penetrate the hard outer skin of grains and cereal products, as well as nuts.
Their life cycle involves the adult weevils laying their eggs in the food
product. The lava or grub hatches out of the eggs. The lava then forms a
case or pupa from which the adult weevil breaks out.
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Moths
Grain or cereal moths also infest most cereal-based foods, such as flour and
breakfast cereal, oats, and so on. They are only small (10–15 mm long) and
may go unnoticed until you spot one of their young caterpillars on the end of
your spoon, just when you are finishing your bowl of muesli!
Figure 6: A moth and its caterpillar
The life cycle of moths involves the adult laying eggs, from which the
caterpillar hatches. The caterpillar, after considerable eating, forms a cocoon
(webbing) from which the adult moth emerges, ready to start the cycle all
over again.
Control of stored product pests
Here are some suggested ways for controlling these pests.
 Check incoming stock for any signs of infestation.
 Monitor stock, particularly the more susceptible dried foods and cereal
products.
 Discard any food or packages as soon as they show signs of
infestation. Leaving just one packet of contaminated flour will allow
the moths or beetles to spread to other food products.
 Clean up any spillages immediately.
 If packaging or seals become broken or damaged, discard or repackage the contents.
 The pests gain all their moisture from the food, so cannot grow or
breed if food is kept very dry.
 Observe strict stock rotation. The longer stock is kept, the greater the
possibility of it becoming infested.
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 The temperature of the storeroom is also very important, since insects
will breed much faster in warm, moist conditions. Pests can be killed
by putting food in a freezer.
Now have a look at coloured print numbers 51–54 for further examples of
stored product pests
Activity 3
1
Outline the life cycle of the cockroach and indicate why it is considered a health risk.
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2
What is the best method to control vermin in food premises?
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3
List three stored product pests.
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_____________________________________________________________________
4
List three methods of applying of insecticides and comment on the effectiveness of
each method against flies and cockroaches.
(a) __________________________________________________________________
(b) __________________________________________________________________
(c) __________________________________________________________________
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Cleaning and sanitation
Cleaning is essential to ensure food safety. There are many reasons that
cleaning is important. Here are some of them.

It helps to ensure the food and premises are wholesome and clean.
Your customers will not come back if you serve them dirty food on
an unclean plate.

It reduces the incidence of pest infestations.

It helps to preserve the safety, freshness and palatability of the
product by removing and restricting microbial activity, and also
helps to decrease the incidence of food poisoning.
Can you think of any more?
Requirements for cleaning
The following are needed for effective and efficient cleaning:

Water

Detergent

Sanitizer

Suitable construction and design and a plan for a clean working
environment
Water
Water is a fundamental tool for cleaning. It is important that it is of
sufficient quantity and adequate quality.
Water used for cleaning in food premises should be of standard fit for
drinking, that is potable.
Finally, apart from the water being clean to start with—and plenty of it—the
temperature of the water is also important. A plentiful supply of hot water is
essential.
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Detergent
After water, detergents are the next most important factor in effective
cleaning. There are many different types of chemical detergents. Some may
be more effective than others, but they all work in a similar way as outlined
below.
How detergents work
The word detergent is derived from a Greek word which means to clean. In
everyday language, we tend to call our cleaning materials either soap or
detergent. However, soap is technically a detergent. In fact, anything which
can clean is a detergent.
Detergents, such as soap and other liquid or powdered detergents, work by
using the special properties of the surfactant they contain. If it were possible
(which it isn’t) to magnify a single, tiny, tiny part of the detergent
sufficiently, you would see individual molecules.
The molecule of a surfactant is large and has, at one end, a water-soluble
part and, at the other end, a fat-soluble part as shown in the diagram below.
When such a detergent is added to water, the water-hating ends immediately
try to get away from the water by going directly to the surface as illustrated
below. This enables water to spread evenly over the surface, distributing the
detergent to places where it is required.
Figure 7: The action of detergent molecules on water and surfaces being cleaned
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Detergents alone will not remove the dirt from the surface. For this,
mechanical action is required. The molecules of the detergent reduce surface
tension and help the mechanical action to remove the dirt.
This mechanical action can be high pressure jets, a brush, rapid movement
of the item to be cleaned, or any other method of scraping or rubbing the
surface. As the dirt is removed, it is surrounded by the detergent molecules.
These molecules give the dirt particle an electrical charge which means the
particles of dirt will repel each other.
This process is illustrated below.
Figure 8: Removal of dirt by detergent
Here you can see the action of detergent molecules on a dirt particle. This
prevents the bits of dirt being removed from the surface from re-depositing
on that surface.
The illustration below shows in a little more detail the washing process
using detergent. The article shown is a spoon, but the principle is the same
for any other surface. (Hot water assists the detergent molecules to remove
and suspend dirt.)
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Figure 9: Processes involved in detergent action on dirt
Types of detergent
There are many different types of detergent. For example, detergents that
may be very effective for removing the build-up of grease and fat from the
inside of an oven may not work so well if used to clean other surfaces. In
fact, they may damage certain surfaces if used for cleaning jobs they are not
intended for; some can even be dangerous or corrosive if not used correctly.
In addition, the type of dirt is important in determining which detergent to
use.
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Types of dirt or soil
Generally, we can classify soils or dirt according to whether they are
organic or inorganic.
Organic soils are derived from animal or vegetable matter, for example, oil,
fat, grease, protein, sugar, starch and cellulose.
Inorganic soils are derived from other substances such as grit, salt, rust and
hard water scale.
What detergent works best with what dirt?
Alkaline or neutral detergents are best suited to removing organic soils.
Acid detergents are suited to removing inorganic soils.
The main types of detergent are summarised below.
Acid detergents
These are only used to remove inorganic soil by reacting chemically with
the soil to form water-soluble substances. They are used when cleaning
porcelain such as sinks and toilets where abrasives or alkaline detergents
could damage the surface, and for descaling urns and so on. Acid detergents
are not very effective for removing grease and so are the least commonly
used detergent.
Alkaline detergents
These are used to remove organic soil. They do so by reacting chemically
with protein, fat, grease and so on, to form a water-soluble substance. Note
that they are corrosive to the skin and will damage aluminium. Mildly
alkaline detergents may be suitable for manual cleaning methods. Gloves
should be worn.
Highly alkaline detergents may be suitable for cleaning really dirty surfaces
such as ovens and in dishwashers, but remember that personal contact with
them will cause burns. Also, take care as they may dull crystal glassware
and corrode aluminium cookware.
Neutral detergents
These are used to remove organic soils and general dirt. They do so by
removing the soil from the surface, dispersing it into small pieces and
suspending it in water. They do not react chemically with the soil.
Neutral detergents do not burn the skin, so are used for manual cleaning.
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Finally, although detergents can remove micro-organisms from the surfaces
being cleaned, they are not designed to kill them. In order to reduce the
numbers of micro-organisms by killing them, we need sanitizers.
Sanitizing
As previously mentioned, detergents on their own will not kill microorganisms. Sanitizing is necessary to kill micro-organisms or reduce their
overall numbers to levels considered to be safe.
Sanitizing involves treating the surface (usually after it has been cleaned) to
reduce or eliminate the micro-organisms present. Sanitizing of surfaces can
be carried out using either:

high temperatures to kill micro-organisms on surfaces, or

addition of chemicals to kill the micro-organisms—that is,
sanitizers.
Heat
Heat, as stated in previous sections, is very effective in preventing the
growth of micro-organisms and in killing living microbial cells.
Very hot water (77–82°C or above), or steam if it is available, is used to
effectively sanitize surfaces in food handling premises.
If heat is used, it is important to allow sufficient time to kill the microorganisms. Although most of the micro-organisms are killed, there are
some, such as the very resistant spore-forming bacteria, which may still
survive.
Heat is very effective, but cannot always be used: Water at 77°C will cause
burns, it is difficult to keep water at this temperature and hot water from a
tap is often not this hot.
Some surfaces, such as benches or floors, cannot easily be heated. If heat is
not used, then chemical sanitizers can be utilised.
Sanitizers
There are different types of chemical sanitizers available. These are
substances which are toxic to micro-organisms. Care must be exercised in
their use because large amounts could be toxic to humans and, if they come
into contact with food, they can contaminate it. Care must be taken during
storage and use to prevent this from happening.
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Correct methods for using different types of sanitizers
Sanitizers take time to kill microbes, so follow instructions. Some sanitizers
are inactivated by other chemicals or by dirt or are effective over a limited
pH range. Many sanitizers fail to kill some types of micro-organisms.
Halogen (chlorine, iodine, bromine)
Chlorine-based products are the most commonly used sanitizers. Chlorine is
cheap, effective, easily rinsed off, easily tested for strength and traces on
food are harmless to consumers. Chlorine is very toxic to micro-organisms
and only very low concentrations are necessary to control them; 50 parts per
million is a typical minimum effective concentration. However chlorine may
be affected by dirt and other chemicals and by temperature and pH, so
follow instructions carefully.
Iodine-based sanitizers may also be used. Iodine can be formulated into a
sanitizer called an ‘iodophor’. Rinsing off with fresh water is necessary
when using these sanitizers to ensure that there is no trace left to
contaminate the food.
Pine and eucalyptus oils
These are quite effective but are expensive and have a strong odour so use
on food handling equipment is limited.
Quats
Quaternary ammonium compounds, to give their full name, are another
commonly used sanitizer. They have the advantages of low toxicity, low
corrosiveness, stability in storage and some cleaning (detergent) ability.
They are often used where one-step cleaning/sanitizing is required. They are
effective where surfaces are not very dirty and any remaining on the surface
is not toxic. Benzalkonium chloride is the active ingredient in the well
known Pine-o-cleen and many other combined detergent/sanitizers.
Disadvantages are a higher cost than chlorine and the possibility that not all
types of bacteria are killed.
Peroxyacetic acid
This compound has been used as a sanitising/wash rinse in products like
bean spouts and salad vegetables. The level used may vary (20-2000ppm)
with the Peroxyacetic acid (CH3COOOH) breaking down in solution
forming the active sanitising agent, ie Hydrogen peroxide (HO-OH) which
then attacks (oxidises) any organic matter such as bacteria.
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Alcohol or phenol-based sanitizers
Triclosan or chlorhexidine are in many anti-microbial hand washing liquids
and some surface sanitizers and dishwashing liquids. Triclosan is included
in some sponge wipes at manufacture to help prevent bacteria growing in
them. Inclusion of Triclosan in plastic cutting boards or containers inhibits
growth on the plastic, but not on the food.
Phenol-based chemicals are commonly used as disinfectants in non-food
applications. Although effective, some have a rather strong smell which
would contaminate food. If you have ever used products like Dettol you
would have experienced this smell.
Three parts denatured ethyl alcohol (methylated spirits) to one part water is
a good surface sanitizer for spraying on dining tables. It dries quickly, but
be aware as it is inflammable!
Propyl alcohol (propanol) is an ingredient in some kitchen
cleaners/sanitizers, and in wipes used to sanitize thermometers etc.
Always take care when handling chemicals:

Some are toxic.

Some are corrosive and will damage surfaces, clothing and your
body.

Some chemicals when mixed will react with each other and
neutralise the effectiveness of both.

Some mixtures give off toxic gas (eg chlorine) or may even cause
fire or explosions.
Always follow the manufacturer’s directions!
This may include using protective clothing, well-ventilated areas, adding
chemical to water not water to the chemical and measuring quantities
carefully.
Never mix chemicals (unless directions on the container say specifically
that it is acceptable to do so).
How much sanitizer to use
The Victorian Dept of Health indicates that utensils and surfaces should be
sanitized using 50–100 mg/L (ppm) chlorine solution. The table below
shows how much food grade chlorine solution to use.
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How much
water?
Concentration
required
5L
How much bleach?
Household bleach
(4% chlorine)
Commercial bleach
(10% chlorine)
50 ppm
50 ppm
100 ppm
2.5 mL
5 mL
6.25 mL
100 ppm
12.5 mL
10 L
12.5 mL
25 mL
5 mL
10 mL
50 L
62.5 mL
125 mL
25 mL
50 mL
Also note that adjusting the pH of the chlorine sanitising solution to
approximately pH6 will improve the effectiveness of the process. For
example, when making up 5L of 1200ppm solution you can add 15ml of
vinegar.
Activity 4
The following questions will help your understanding of the work covered so far.
The answers are at the end of this section.
1
Describe a detergent (surfactant) molecule.
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
2
What is the difference between a detergent and a sanitizer?
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
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Cleaning and sanitizing programs
General cleaning method
Most cleaning procedure can be summarised as set out below. Steps may be
skipped or combined in particular instances.
1
Pre-clean. A pre-clean involves removing any obvious, large easy-toremove dirt. This could simply mean sweeping the floor before washing
it, wiping down a bench top used for preparing food to remove any
crumbs and bits of food and scraping off plates, pots and pans.
2
Wash with clean water using the correct detergent. The selection of the
detergent depends on the nature of the surface and the dirt to be
removed; each schedule will specify the best detergent to use.
Physical work is usually necessary to remove dirt and suspend or
emulsify it in the water. This may involve simply good old elbow
grease. Mechanical action such as scrubbing or high-pressure water
spray may also be utilised. Heat is usually required. Generally, water
should be at least 45°C to melt fats and assist the chemical action of
detergents.
3
Rinsing removes dirt and detergent from the surface being cleaned. If it
is not rinsed off it may accumulate on the surface and the action of
sanitizers may be affected. (One example of inadequate rinsing is clear
in licensed premises. It makes your beer go flat!)
4
Sanitize if necessary. When heat or chemical sanitizer is used, it is
essential to allow sufficient time for either to be effective. Commercial
dishwashers use very hot water (>77°C) or chlorine in their rinse cycle.
5
A final rinse if a chemical sanitizer has been used. This may not be
necessary if heat sanitizing has been employed.
6
Leave the surface dry. This is very important as micro-organisms may
grow in wet conditions as wet surfaces; will also attract more dust and
dirt.
The above is just one example of a general cleaning method. It may vary
depending on the application.
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Removable equipment
Removable equipment such as cutting boards, buckets, trays etc should be
treated in the following manner.
1
Dry clean then rinse with water.
2
Scrub until clean in hot water (minimum 45°C) containing neutral
detergent until all dirt is removed.
3
Rinse with clean hot water (minimum 45°C).
4
Sanitize with chlorine (follow pack instructions for concentration, time
and temperature).
5
Rinse with hot water (minimum 45°C).
6
Place each item in a position to drain and allow air-drying. Do not stack
until properly dry.
Polythene cutting-boards are liable to have a scored surface which is
difficult to clean and sterilise. For this reason they are a potential source of
contamination and should be treated regularly through the working day to
prevent a build-up of micro-organisms. They should be re-surfaced using a
belt-sander at regular intervals.
Where ever possible, use impervious contact surfaces to minimise microbial
harbourages.
Dishwashing requires that procedures are carefully verified unless
commercial dishwashers are used. These are generally effective and sanitize
by using a high temperature of at least 77. Domestic dishwashers use lower
a temperature but may be satisfactory as cycle times are longer. When
washing utensils manually it is usually impractical to maintain a water
temperature hot enough to sanitize effectively so chlorine is a more effective
method; 50 ppm chlorine is generally effective, though this should be
verified for particular conditions.
What information should cleaning programs include?
In addition to the above information, a cleaning program should include:

information on frequency of cleaning

what chemicals to use

temperatures

what equipment is needed

how to dismantle equipment to be cleaned

safety precautions.
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The cleaning program should also nominate the person responsible for the
cleaning. A record of completion of cleaning is often useful evidence that
will help support food safety auditors.
Cleanliness tests
There are a number of simple tests that can be used to see if a surface is
clean.

There should be no visible contamination.

The working surfaces should not feel greasy or rough.

When a clean, white tissue is rubbed over the surface it should not be
discoloured.

The area should be free of abnormal odours.
Microbiological testing
More sophisticated micro-biological tests are sometimes used to determine
the actual number of micro-organisms left on the surface. These involve
sampling a section of the surface being cleaned and determining the microorganisms left.
Below are some examples.
Measure of
cleaning
Measure of
sanitizing
Surface bacterial count 6.3cm
(1 square inch)
Surface washed
not sanitized
Surface washed
and sanitized
less than 1
satisfactory
satisfactory
less than 10
satisfactory
borderline
10 to 100
borderline
contaminated
100 to 1000
poor cleaning
contaminated
Microbiological testing is the definitive test as to whether cleaning has been
effective. However it takes time—typically 24 hours or more—to get results
from microbiological testing, so this is mostly used as a reference test.
The Australian Standard HB224:2001, Appendix C states that ‘as a guide an
adequately cleaned and sanitized food surface should not have more than
100 colonies per utensil or per area of equipment swabbed (10cm2)’.
For immediate results, the above simple tests are an indication and may
suffice for some surfaces. A better indication of cleanliness can be gained
by testing for organic matter on the surface. Test kits are commercially
available which indirectly determine the presence of microbial
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contamination by detecting the presence of protein or carbohydrate on a
surface. Simply swabbing the surface and placing the swab in a ready
prepared solution gives a colour reaction which easily interprets the
effectiveness of the cleaning process that may (or may not) have occurred.
Now have a look at coloured print numbers 55–65, which show examples of
appropriate and inappropriate cleaning.
Activity 5
The following questions will help your understanding of the work covered so far.
1
List the main steps in the generalised cleaning method.
_____________________________________________________ ________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
2
What information should be covered by a cleaning schedule?
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
3.
The following terms featured in this topic. Jot down their meanings in the second
column. These are important terms so it would be a good idea to work through the
section again if you are unsure of their meaning.
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Word
Meaning
acute poison
chronic poison
humidity
rodents
stored product pests
vermin
acid
alkaline
corrosive
inorganic
molecule
neutral
organic
potable
sanitizer
toxic
water soluble
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Summary
Now that you have completed this topic you should be able to advise food
handlers how to:
 prevent and minimise potential health risks caused by the pathogens
they harbour
 reduce damage, loss and wastage due to contamination caused by
pests
 avoid prosecution because of the presence of pests on their premises
 maintain customer satisfaction.
Also, remember that good cleaning is important because it:
 extends the storage life of raw and processed products
 reduces the risk of the product being involved in outbreaks of food
poisoning
 reduces the number of product rejections, returns and complaints
 reduces maintenance costs and lost time through breakdowns by
regular dismantling and checking of equipment
 reduces the environmental contamination with micro-organisms
 improves working conditions and encourages better hygienic practices
by employees.
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Glossary – Pest control
acute poison
kills with one dose.
air curtain
fan blowing air downwards over a doorway to reduce movement of heat and
pests through the opening.
carrion
dead and putrefying flesh.
chronic poison
repeated doses are necessary to kill; safer than acute poisons.
Drosophila
vinegar fly, ferment fly or fruit fly; not to be confused with the Queensland
fruit fly.
knock-down
rapid acting (insecticide etc).
larva
first stage after egg in life cycle of many insects (eg grub, caterpillar, maggot).
nymph
immature stages in life cycle of insects which do not form larva and pupa (eg
cockroaches).
pupa
resting stage between larva and adult in insect life cycle.
residual insecticide
one which is relatively long lasting; often applied as a spray on surfaces or as a
powder or ‘dust’.
rodent
group of animals including rabbits and guinea pigs as well as pests such as rats
and mice and many other animals.
vermin
pests—animals and insects.
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Glossary – Cleaning and sanitation
acid
alkali
buffer
cleaning
cleaning schedule
detergents
disinfect
disinfectant
hard water
emulsion
hydrophilic
hydrophobic
infect
neutral
particulate
pH
potable
sanitize
sanitizer
sterilize
surface tension
surfactant
water softener
a substance containing hydrogen ions, strong acids are corrosive, especially
to metals. Acids taste sour.
a substance containing hydroxide ions—strong alkali which is corrosive to
fats and proteins.
a substance which resists change in pH.
the process of removing any unwanted contaminating materials (grease, dirt,
food, dust, stains, and so on.) from any surface of equipment, utensils, and so
on.
a statement of cleaning methods and frequency.
a product used to remove dirt and some micro-organisms from the surface
being cleaned. We shall be studying detergents in more detail later in this
section.
to kill or remove infectious micro-organisms. Often applies to skin, wounds,
and so on.
chemical used to kill microbes. Used in non-food areas; often has strong
odour.
water containing calcium or magnesium salts. Hard water reduces
effectiveness of some detergents, especially soap.
a suspension of fine particles of oil in water, or water in oil.
literally ‘water-loving’. Soluble in water but not in fat.
literally ‘water-hating’. Soluble in fat but not in water.
to contaminate with harmful organisms.
neither acid nor alkaline, ie pH7.
existing as particles.
scale 0 to 14 used to measure the level of acidity and alkalinity. Strong
acid = 0, neutral = 7, strong alkali = 14.
water suitable for drinking.
eliminate micro-organisms or reduce their numbers to safe levels on the
surface; usually takes place after cleaning
chemical used to kill microbes. Suitable for use in food areas.
totally eliminate or destroy micro-organisms; this is rarely required, or
carried out, in food premises.
the tendency of the surface of a liquid to contract. It forms liquid into drops
and so reduces ability of liquid to spread over surface or ‘to wet’.
‘surface active agent’; a substance which reduces surface tension of water;
essential active component of most detergents.
a substance reducing the effect of hard water in making detergents less
effective.
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Answers to activities
Activity 1
1
How many hygiene problems can you list from this illustration? There
are heaps!! For example:

Numerous cockroaches

Presence of cat, and mouse droppings (yuck!)

Benchtop appears to be made of porous material such as wood and
is also covered with dirt and has a damaged surface

A person is obviously ill and has symptoms of the flu and may touch
his nose and mouth with his hands whilst handling food

Clothing is soiled and in disrepair

Breach of building codes evident—for example, unsealed walls,
insects, dust and other airborne particles could enter through open
window.
Now find some more! And don’t eat food from that premises!
Activity 2
1
2
What are the main indicators of pest and hygiene problems?

visible appearance of cockroaches

rodent droppings
 food left exposed to potential contamination and so on.
Do you think these indicators are problems for commercial food
premises? Most definitely. All food premises should conform to all
hygienic food-handling requirements.
Activity 3
1
Adult—egg case—nymph—adult, inhabits unsanitary
environment/harbours pathogens which can be transferred to food.
2
Preventive methods—that is good housekeeping, sanitation/hygiene,
preventing entry and eliminating harbourings...
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3
grain weevil, confused flour beetle, Mediterranean flour moth.
4
(a) Fumigation—for total control, kills all vermin (and anything
else around!).
(b) Aerosol sprays—general purpose for mainly flies (not very
effective for cockroaches), contains pyrethrins.
(c) Surface spray—specific for cockroaches; the walk-on chemical
is absorbed through skin (eg organophosphate chemical.)
Activity 4
1
The molecule of a surfactant is large and has, at one end, a watersoluble part and, at the other end, a fat-soluble part . See Figure 7.
2
A detergent is an agent which assists cleaning (ie removes microorganisms from surfaces). A sanitizer is a substance that reduces
bacteria to safe numbers (ie kills micro-organisms).
Activity 5
1 (a) Pre-clean
(b) Wash
(c)
(d)
(e)
(f)
Rinse
Sanitize
Rinse
Dry
2 (a) How often and when cleaning is done?
(b) How to clean, and equipment needed?
(c) What materials to use—detergent, sanitizer?
(d) Dismantling of equipment for cleaning, if applicable.
(e) Safety precautions necessary.
(f) Who is to do the cleaning?
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