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Ian Harper

All You Need To know About Hygiene

115 min read

ALL You Need TO Know About Hygiene


1 © 2003




Cleaning in today’s working environment has to include hygiene considerations.


We emphasise the need to observe


•      personal hygiene


•      hygienic cleaning processes


•      care in the disposal of waste


However the whole process of cleaning directly contributes to hygienic buildings. In the Hospital Service good cleaning is of the first importance above the general use of disinfectants.


This section of your work covers


•      personal hygiene – most important to the health and safety of each of us and to the image of your company


•      micro-organisms (germs) and how they operate and can be controlled – the foundation to good cleaning processes


•      notifiable diseases – your obligations as an employer of labour


•      pests and their control – a subject of mounting interest as we put up more and more buildings just made to harbour pests


•       waste management – an activity which occupies a substantial part of cleaners’ time and in which there are health and safety responsibilities


•      monitoring standards of cleanliness - the job we all have


The section aims to take a general view of the whole subject of hygiene at a basic level. Good hygiene is important as the basis of good cleaning. For you to be informed on the subject is as essential to you personally as well as for your company.


Cleaners are hygienists. They provide for others the clean environment in which they can safely work, play, learn, recover from illness, travel, wait etc. The list is endless.


Cleanliness is said to be next to Godliness – perhaps that indicates the importance that we may wish to place on it.


In their daily duties cleaners throughout the world have access to and contact with an unparalleled variety of different environments and people.


People rely on cleaning staff to do their job to the best of their ability. They require standards which are set, achieved and maintained.


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To do your best you must have the correct equipment in good working order. You would no more consider using your toothbrush to clean the toilets than using a floor mop to scrub your back! The equipment is not suitable for the job.


But put aside equipment for the moment and consider your best and most important working tool. Your body. It only works well for you and others if it’s treated with care.


Remember all those other people that you have access to, their homes, hospitals and schools? Your obligation to them is to provide hygiene through cleaning. If people can appreciate that a dirty mop spreads disease why can’t they apply the same principles to their own bodies?


A high priority for the cleaner must, therefore, be personal hygiene in view of the scores of people dependent on them.

Clean is the absence of any visible soil.


Once again, people often say


•      not smelling badly


•      clean


•      washing properly


Clearly the aims of cleaning and hygiene overlap considerably. Any cleaner must also be a hygienist. Here are two definitions of hygiene which we could use.


The practices and procedures essential to the maintenance of health and the quality of life.


The recognition, prevention, removal or control of factors which tend to produce ill health or diminish the quality of life.


This should ring a bell. Surely in part this is why we have to clean.


Hygiene, both personal and environmental, needs to consider many factors, not least of which are the microscopic organisms. They live in, on and around us.




At their largest they are the smallest thing the eye can see – a tenth of a millimetre. Many of them that cannot be seen as individual ‘bugs’, can be seen growing in groups as ‘colonies’.


Often it is the characteristics of the colony which help lead to correct identification of the micro-organism.




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The colonies are grown on a nutrient medium called agar. It is jelly-like and was originally derived from seaweed.


If it is necessary to observe individual micro-organisms they are placed on a glass slide, stained to make them easier to see, and observed under a microscope.


There are basically two types of microscope. Those which use light and those which use electrons. For the routines observation of most micro-organisms a light microscope is used.


Light microscopes can usefully magnify up to 1000 times. Even at this apparently huge magnification many micro-organisms are still tiny, and yet others are so small that they still cannot be seen.


To observe the very smallest of organisms the electron microscope is used. As its name suggests it uses a beam of electrons rather than a beam of light. This type of microscope can magnify up to half a million times.




Many micro - organisms have evolved special relationships with man. They can live on him, that is, on and within the skin. They can live within the natural holes, cavities and tubes of the body, for instance, inside the gut. They can live within the organs and tissues. They can live inside the cells that make up your flesh.


In all of these cases man is the host.


There are several things common to all micro-organisms where man is host.


They must be able to live, reproduce and feed at human body temperature - 37◦C.


If the man and microbe find they cannot live together, man tries to rid himself of the bug. One way is to make the living conditions uncomfortable. This is done by raising the body temperature. When you do this you are said to be ‘running a temperature’.


There are three states in which man lives with micro-organisms.




Commensals are organisms which benefit from living on or in man. The organism gains but they do not usually harm man, the host. Many bacteria which live in the gut of man are commensals. They form p art of the normal residents in the gut and, in the language loved by scientists, are called ‘part of the normal gut flora’.


Under certain situations, for example if their numbers get too high, they can cause harm. When micro-organisms of any type are harmful to man they are said to be pathogens and are pathogenic, that is, they can cause disease.






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Micro-organisms which are symbiotic live to the mutual benefit of both man and microbe. The organism does not harm man. It takes from man his warmth, an address, food and all the things needed for a happy existence. In return it supplies man with something he needs, for example, Vitamin K.


On his own man cannot produce this vitamin which is essential for the clotting of blood. Instead, symbiotic bacteria produce it for him whilst living in the gut. These are also part of the normal gut flora, in fact we could not survive without them.


We also have symbionts living on the skin. Their presence prevents unpleasant microbes from colonising the skin.


Just as with the commensals, if the number of symbionts gets too high, the benefits are outweighed by the losses and they can then become pathogenic. It’s all a matter of balance.




Parasites live at the expense of man. They gain while man loses out. Parasites are of two types.


Obligate parasites, as their name suggest, live an obligatory parasitic existence – they can’t live any other way. It is not in their interest to kill the host – if the host dies, the parasite also dies.


All viruses are obligate intracellular parasites. That is they live within the living cells of the body. Viruses sometimes kill people. When the cell dies so does the virus unless it can rapidly gain access to another living cell.


Facultative parasites can invade living organisms and, if they kill the host, they continue to live on the dead remains. Dead and decaying bodies thus act as a reservoir for these organisms which can go on to re-infect another person.




There are millions upon millions of micro-organisms. The vast majority are in no way harmful to man. In fact many are useful in


•      food production eg baking, cheese making


•      brewing


•      the tanning of leather


•      the breakdown of leaves etc to form part of a good soil


Because there are so many different kinds of micro-organisms, we need to have some way of grouping them together to decide how to deal with them. For most purposes it is possible to divide micro-organisms into four groups





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•      Protozoa


•      Fungi


•      Viruses


•      Bacteria




Their name means ‘first animals’. They are the most humble animals in existence. So far as size goes, they range from 0.1mm to 0.01mm.

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In the UK parasitism by protozoons (that is the correct spelling for more than one member of the family of protozoa) is quite rare.


Pathogenic types can cause these diseases


•      Amoebic dysentery


•      Malaria


•      Sleeping sickness


Ingestion (eating) or injection of protozoa can cause disease to be passed from one individual to another.




These are not really true plants nor are they animals. To a degree they have characteristics of both.


The large of macroscopic fungi do not really concern us unless you mistakenly happen to eat one of the more poisonous forms, for example Fly Agaric.


The small or microscopic fungi are the ones which can cause disease. They can grow as single cells, for example, yeasts, or as colonies of multicellular filaments called Hyphae, for example, moulds.


They reproduce by means of microscopic spores.


Spores are like seeds produced by flowers except they are much smaller. When they find the right conditions, they germinate to produce a new fungus.


Spores can survive for a long time just waiting for the right conditions to germinate. They can be passed from one person to another on clothes, shoes, socks, comb, hat or simply by hand contact.


Some species are able to cause disease in man. Fungal diseases are called mycoses.



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Here are some common examples of diseases caused by fungi.


•      Thrush caused by a yeast called Candida albicans


•      Athletes Foot caused by a fungus called Tinea pedis


•      Ringworm caused by a fungus called Tinea capitis




The smallest identifiable organisms. They are only truly alive inside of the living cells of a host. They are unaffected by antibiotics. Their reaction to disinfectants is variable. Infectious hepatitis needs to be treated with strong hypochlorite disinfectant whereas the virus responsible for AIDS is easily killed by even mild disinfectant solution. (More about that later)


Many viruses cause us no harm at all. In fact, one called a T-phage virus kills bacteria. It has a characteristic shape which looks like a lunar landing module.


Diseases caused by viruses include


•      The common cold – Rhinovirus


•      Influenza – Flu virus


•      Glandular fever – EB virus


•      Cold sores, chicken pox – Herpes virus


•      AIDS – Human Immuno-deficiency Virus


•      Rabies – Rhabdovirus


•      Infectious hepatitis – Hepatitis virus B


•      German measles – Rubella virus


•      Warts – Papilloma virus


•      Smallpox – Pox virus


Like most parasites, viruses are largely host specific. There are always exceptions, rabies is one. Outside of the body viruses are considered to be groups of chemicals with no capacity for reproduction. Some can survive in this dormant state for ages until they acquire access to a body through a route which enable them to reproduce. Inhaling an influenza virus will thus cause ‘flu’.






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Other viruses die within moments of being exposed to the outside air. The AIDS virus is one such example. As yet there is no cure to viral infections. The body has its own weapon for protecting itself from viruses, called Interferon. It is, however, specific to each person and cannot be mass produced.


Vaccination stimulates the body’s immune system. The vaccines use either weakened viruses, for example, weakened polio virus on a sugar cube; or non-dangerous but similar viruses, for example, cow pox. The body is prodded by the vaccine into a state of alertness ready to attack and destroy invading viruses.


Vaccination against many diseases, both bacterial and viral, is carried out at about 10 weeks of age. BCG jabs against TB are often done at school.


Females must make sure that they have been vaccinated against German measles some months prior to the onset of a pregnancy. This virus causes malformation of the foetus leading to potentially gross deformity.


Regrettably at the present time there is no vaccine for AIDS.


AIDS – Fact and Fiction


AIDS stands for Acquired Immuno-Deficiency Syndrome.


•      Acquired – you have to catch it


•      Immuno-Deficiency – it reduces your ability to resist infection


•      Syndrome – it has a recognisable progress with characteristic signs and symptoms


It is caused by a virus called Human Immuno-deficiency Virus. HIV for short.


There is as yet no known cure.


It acts by disabling one particular population of white blood cells called T-Lymphocytes. Without their help we are less able to cope with infection and our bodies become open to invasion by organisms which it would normally be able to repel.


AIDS is very, very difficult to catch. It has been calculated by St Mary’s Hospital that you would need to inject a person with over a litre of infected saliva before he or she would stand a chance of contracting AIDS from saliva.


So although it is present in minute quantities in saliva, it is of such low infectivity you would have a one in several million chances of catching it from


•      Kissing


•      Using crockery used by AIDS patients


•      Mouth to mouth, or nose, resuscitation





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•      An AIDS victim coughing or sneezing near you


•      An AIDS victim sharing the same room with you


•      An AIDS victim touching you


In fact you stand more chance of being kicked to death by a mule than catching AIDS from physical contact or saliva.


Neither urine nor faeces are highly infective.


AIDS is less infective than Hepatitis B or flu.


The virus is remarkably delicate. It is killed easily by


•      A hot detergent solution


•      All disinfectants


•      Being outside of a living human body


It is by all counts all but impossible to catch, and easy to kill in the environment.


So why all the worry about it, you may be asking? The answer lies of course in the fact that, if you do catch it, it is very difficult to get rid of.




Things you will need if you have to deal with spillage of blood, urine, faeces, or vomit and how to use them are


•      Overalls – if you have special disposable overalls all the better, if not then your existing protective clothing will have to do


•      Rubber gloves – again the disposable type are preferred.


•      Safety signs – to indicate cleaning in progress


•      Strong disinfectant solution such as a 10% hypochlorite solution is acceptable


– better still are powders of hypochlorite or those containing Sodium Dichloroisocyanurate


•      Disposable wipes or tissues to gather up the waste


•      A sealable plastic sack or container which can be incinerated – any used wipes and residues are placed in here along with disposable items of clothing


•      A mop with removable head which can be sterilised after use or a scrubber drier




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•      A further disinfectant solution to mp the floor with once the bulk waste has been removed and the floor cleaned




•      self protect with gloves/overalls etc


•      sprinkle the powdered disinfectant liberally over the spillage


•      remove the spillage using disposable wipes and place the waste in a disposable plastic sack


•      machine scrub or mop the floor using neutral detergent solution


•      disinfect the floor using a 1% hypochlorite solution




These are microscopic unicellular (single cell) organisms. They do not have the same structure or chemistry as human cells.


These differences are used to identify and kill them.


Broadly all bacteria fall into one of two groups based on their ability to take up a stain called Gram’s stain. Those which take up and hold the stain are called ‘Gram-positive’. Those which do not hold the stain are called ‘Gram-negative’.


The staining reaction is a feature of the bacterial cell wall. This same feature also determines the extent to which the bacteria will be affected by disinfectants. Gram-positive bacteria are more easily killed by disinfectants in general than Gram-negative bacteria.


There are a vast number of different types of bacteria. They have different shapes and sizes.


Many bacteria join together as chains or clumps. Some have projections and some have altogether strange shapes. Here are a few with their names.


1.                 The Round Bacteria – Cocci







Saprotrohic micrococci








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2.                 Rod Shaped Bacteria


TB bug


























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Tetanus bacteria









These form spores. Spores are a resistant stage in


The life cycle of certain bacteria. They are resistant

To conditions of cold, heat, no food and no water.

Spores can survive for long period in soil or dust.

Spore forming bacteria are especially dangerous.

Normal methods of disinfection by heat or

Chemicals may fail to kill them.









3.                 Comma Shape















Growing as colonies in a Petri dish containing agar they may appear like this.





All bacteria need


•      A place to live


•      The right temperature


•      The right food and enough water


•      The right conditions of acidity or alkalinity





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•      The presence or absence of free oxygen


A place to live


Most bacteria which are dangerous to man are parasites. They thrive best either on him or in him. Man is the place where they succeed.


Many microbes are very specific about this. Man and man alone will do! Some bacteria are less particular, living for example in chickens when alive and man when the chicken is eaten. Others can survive in dust, water and the surroundings of man but only become really active once on or in him.


The right temperature


Every living organism has a minimum temperature below which it cannot grow or dies: and a maximum temperature above which it dies: and an optimum temperature at which it grows most successfully.


Most bacteria and other microbes which are capable of causing disease in man have an optimum survival temperature of 37◦C. This is the same as man’s body temperature. This is not a coincidence, it is by design. The microbe is a parasite and in order for it to be a success it must endure the same conditions as man or fail.


The right food


All bacteria and microbes have specific feeding requirements. Where the nutritional requirements of the bacteria are similar to that of man we may eat them in our food.


Bacteria which gain entry to the body may find the internal environment quite literally to their taste. They invade tissues, cells and fluids. They multiply at the expense of man, who suffers. They may even produce poisons. In the end their success may lead to the death of their host.


Some bacteria are external parasites living on the skin and its secretions.


The right acid or alkaline conditions


All bacteria have an optimum pH for survival. pH, as you may know from your studies on cleaning agents, is a scale measuring acidity or alkalinity. Where the internal or external parts of man meet with the needs of the microbe they can happily thrive.


The right conditions of oxygen


Some bacteria can only live deep within the tissues of man where the free oxygen levels are low. Others need to have more free oxygen or they suffer.


How Fast Do they Multiply?






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Bacteria reproduce by dividing in two. Once the conditions for the good life are satisfied many of them will divide every twenty minutes. This may not sound a lot but, if you work it out, one of them will turn into a population of a quarter of a million in 6 hours.


They also have a short life and the smelly mops in badly kept cleaners’ cupboards smell of the rotting bodies of dead bacteria.


What does all this mean to us?


Bacteria must be present in order to multiply on some dangerous site. For example, in a dirty mop bucket or in a cut finger.


Air always contains both harmful and harmless bacteria. Only when the air is damp, warm and not moving is this a problem. So ventilation is important – particularly in toilet areas.


Standing water, especially when dirty, will be a source of harmful bacteria. The kind that will drop out of the air and breed there depends on the location.


•      Food poisoning types in kitchens


•      Would infection types in hospitals


•      Bacteria from the human gut in toilets


When toilets are flushed, mops are wrung and floors are scrubbed, water is dispersed into the air in the form of droplets which will contain bacteria.


Cleaning and disinfectant solutions which are left to stand too long, buckets which have been left unwashed and not dried out will also be contaminated by bacteria.


Particles of soil brought in on feet. The earth outside buildings can hold 3 million bacteria to the gramme many of which can be harmful. As about 90% of the dirt in a building is carried in on people’s feet it will also have a good population of bacteria. From our point of view this lends a lot of weight to the need for


•      Barrier matting to wipe the dirt of people’s feet at the building entrance


•      the regular cleaning of floors


Human Bacteria We are all good carriers of bacteria. In our gut, noses and throats, we carry the germs that can cause food poisoning and wound infections.


Waste and Refuse Food waste and clinical waste are obvious sources of infection. What is often ignored, by everyone other than the cleaner, is that office waste baskets often contain food and drink residues.






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Pests These are well-recognised as carriers and transmitters of disease. Our responsibility is to spot signs of pest contamination and to keep places clean enough not to attract pests.


The normal concentrations of bacteria present in our everyday lives are not a problem. We have our own mechanisms, including friendly bacteria, which help us to cope with them. The problems arise when bacteria are permitted to breed in unusual numbers or get into our bodies in the wrong place through cuts or swallowing.




The simplest, cheapest and best method for the control of micro-organisms is good housekeeping. And that means effective cleaning.


Neutral detergent solutions used correctly will remove and kill 80% of micro-organisms. Chemical disinfectants should only be used when there is an absolute need – in other words, very rarely.


Most disinfectant policies reflect this idea. In places where hygiene is of the utmost importance you will not find chemical disinfectants being routinely used.


If disinfection of mop heads, linen, cloths, or any such items is called for, the first thing to think of is heat disinfection.

The right temperature for the right amount of time kill microbes Very effectively and is much more reliable than chemicals.


Heat Disinfection


There are two types of heat disinfection


•      dry


•      wet or moist


The amount of heat, type of heat, and for what time is determined by the fabric of the item to be disinfected. It is no use putting plastics into a hot air oven to be disinfected if at the end they are nothing more than a molten blob.


For this reason plastics have been made which can withstand high temperature disinfection. Polypropylene is an example.


Disinfection and sterilisation are not the same.


Disinfection means a reduction in the number of microbes.


Sterilisation means total destruction of all living organisms.


It is not always necessary to sterilise – disinfection will sometimes do. Reducing the number of microbes to a safe level will be perfectly acceptable around normal healthy




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people. Sterilisation is sometimes the only acceptable option however where people’s resistance is low – for example in an operating theatre.


What then do our two heat options give us?






Dry Heat


Dry heat in a hot air oven at a temperature of 160◦C for 1 hour will kill all living organisms.


When the temperature is raised to 180◦C the holding time can be dropped to 7.5 minutes.


Wet or Moist Heat


Water is a better conductor of heat than air. Wet heat temperatures are therefore lower than those needed for dry heat for the same level of result.




Pasteurisation is always preceded by cleaning.


Pasteurisation aims to kill of most, but not all microbes. The time needed to achieve this (the holding time) is related to water temperature.


As the temperature goes up, so the holding time goes down.


•      At 65◦C, pasteurisation takes 10 minutes


•      At 71◦C, pasteurisation takes 3 minutes


•      At 82◦C, pasteurisation takes 1 minute


When viruses such as Hepatitis B are suspected then the contaminated items should be pasteurised at 95◦C for 10 minutes.




Boiling water has long been used to disinfect.


Boiling articles in water for 10 minutes will kill all but the resistant, spore, stage of certain bacteria.


Boiling water under pressure


An autoclave is like a pressure cooker whose function is to completely sterilise.






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When water is boiled in a sealed vessel the pressure rises. As the pressure rises so also does the boiling point. As the boiling point rises so the necessary holding time goes down.


This means that at 1 bar of pressure, water boils at 121◦C. The holding time needed to sterilise at this temperature is 15 minutes.





There is no single chemical disinfectant which is capable in or suitable for all situations. If you think you may have to use a chemical disinfectant then consider each of the following


•      is it designed to kill micro-organisms or merely to stop them multiplying – in other words is it bactericidal or bacteriostatic


•      is it active against all, or only some microbes – is it suitable for the intended use


•      do you use it neat, or does it have to be carefully diluted in water or alcohol


•      if a solution is needed, has it been freshly made up to the manufacturer’s specified dilution


•      what is the shelf life of the chemical – is it old and weak


•      how long does it need to be in contact with the surface before it does it job properly


•      how often does the solution need to be changed


•      is it neutralised by other chemicals, organic material, hard water, or synthetic materials such as plastic


•      will it adversely affect the product or surface it is to be used on


•      do protective measures need to be taken when using it – wearing gloves, overalls or goggles; what action should you take if it does get onto the skin


•      will it leave an unpleasant taste or odour on surfaces or products


•      can heat be used as an alternative


A Working Guide to Disinfectants


As few different types of disinfectants should be kept as possible. This will lessen confusion.





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Make sure that you know what you are using and how to use it properly. The label should tell you this. If in doubt ask.


Never keep a disinfectant solution. Discard immediately after use.


Never leave items standing in a disinfectant solution overnight.





These are widely used and are acceptable where hygiene is important, providing the correct concentration and contact time are used.


Neat powders are available. They have a longer shelf life than solutions. They are highly corrosive and bactericidal in the presence of water, Water is essential for all hypochlorite activity.


The strongest solution provided is usually 10% made up in water. This is the same as saying 100,000 parts per million (ppm) available chlorine. Hypochlorite in this concentration is corrosive to the skin and certain surfaces and fabrics such as aluminium, stainless steel, cotton, nylon and some plastics.


A 1% solution provides 10,000 ppm available chlorine. This is still corrosive and protection is needed. It is highly bactericidal and is often kept as a working solution for use against blood spillage and vomit. In such cases it is assumed that the spillage is carrying infective viruses and/or bacteria. A 0.1% solution, providing 1000 ppm available chlorine is used on soiled surfaces. However, whenever possible, soil should be removed using a neutral detergent solution before disinfection. This will enable you to use a weaker solution, 0.01-0.02%, providing 100-200ppm.


0.01% solutions are considered weak. They leave no odour or taste. They can be used on crockery and in food preparation areas.


Hypochlorites in general are inactivated by organic material such as vomit, some plastics, proteins and chemicals such as quaternary ammonium compounds (usually known as QUATS – another disinfectant).


They should never be mixed with other chemicals because they may give off chlorine gas which is very poisonous.


Contact time on a clean surface to kill 99.999% of micro-organisms is 2 minutes using a 200 ppm solution. With increasing bulk of organic matter – dirt or food contamination – inactivation of the disinfectant and its penetration to the microbes becomes a problem. In such cases more concentrated solutions and more of them need to be used.


The hotter the solution the more active the disinfectant action.

Disinfectant activity doubles with every 10 degree rise in temperature






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Hypochlorite solutions ‘go off’ rapidly. Always make up a fresh solution when use is necessary.


Hypochlorite solutions can be stabilised by the addition of sodium chloride. Miltons sterilising solution is a weak hypochlorite solution with sodium chloride added.




Chloramine and dichloroisocyanurates


These are normally supplied as a powder. The advantage to powders is their longer shelf life. In contact with water they release chlorine. They can be made up as solutions from the power. Overall they have the same effectiveness and limitations of hypochlorites.


Clear soluble phenolics


Again these are widely used. Mostly for environmental sanitation. A 1% or 2% solution is a strong working strength. They kill fungi, most bacteria and some viruses but have little activity against bacterial spores. Their main use is on hard surfaces where a reliable kill is required.


They are corrosive on skin so protective measures should be taken.


Unlike the hypochlorites, they are less readily inactivated by organic material and may be the disinfectant of choice when the only consideration is microbial kill.


They are inactivated by certain plastics, rubber and cationic chemicals.


Their taste and smell is strong and lingering – it contaminates food. For this reason they are not used in food preparation areas.




These are often combined with Quat and alcohols to provide skin disinfectants. In this area they reign supreme. Cetrimide is an example. They should not be used as environmental disinfectants.




Alcohols such as ethanol and isopropanol are good disinfectants with a broad range of activity. Their main use is as a skin disinfectant or a component of skin disinfectant compounds.


Quaternary Ammonium Compounds (QUATS)


These should not be used in areas where hygiene is important. They have a limited range of microbial kill. They are particularly ineffective against Gram negative bacteria. One bacteria in particular called Pseudomonas aeruginosa will happily grow in the disinfectant.




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Recent additions of a chemical called EDTA has made them more effective against Gram negative bacteria but they are simply not reliable enough for good hygiene.


They are non-toxic, non-irritant and do not smell. That makes them useful in food preparation areas and as components of skin disinfectants.


They are however, inactivated by neutral detergents, and many other cleaning chemicals. This is because they are cationic. Most others are anionic and carry an opposite electrical charge. (See Cleaning Agents section)


Hard water, plastics and organic matter also inactivate them.




Radiation, such as gamma radiation or ultra violet light, is also used to kill microbes. Because of the danger to people, disinfection and sterilisation involving these forms of radiation are carried out in sealed rooms.


They are used for specific forms of disinfection and sterilisation. For example pre-packed syringes are exposed to gamma radiation.


Cabinets in which work on dangerous bacteria is carried out may be fitted with an ultra violet light source. This ensures that the cabinet is sterile. The light is turned on once work is complete.




Hygiene can be usefully divided into two recognisable areas. The first considers the cleaner as a person who needs to be hygienic. The second, the environment where the work is done.


Personal hygiene relates to the personal practices and habits which ensure the wellbeing of the individual and those with whom he or she comes into contact. To suggest that someone is un-hygienic is a lot like implying they are a bad driver or a poor lover.


Each of us have our own personal codes, practices and standards. As children, measurement of standards is often brutal. Greasy Graham, Smelly Smith, Bad-breath Brian, Pigpen etc. Parents also instil their values in their offspring. Energetic neck, face and hand scrubbing has left many a child vengeful but glowing. Teachers, parents and peers all contribute to the barrage of information leaving no doubt as to your personal hygiene status.


As we grow older and pass through puberty a flawless skin can be overnight transformed into the surface of the moon. Why does it bother us? Again because it implies lack of washing rather than unsympathetic hormones. It is the loss of self - image and comment from our peers that presses our bodies more often into a bath of steaming water.




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As fully-fledged adults less and less is said directly. People may move away from you, but there are some things that, as an adult, even your best friends won’t tell you!


If you work on your own in the middle of Siberia, no problem (for others anyway). Most of us have to work with others. From personal self-respect and respect for those we work with we keep our standards up.


Nevertheless there are occasions when particular attention has to be paid to personal hygiene and the adult reluctance to talk about it has to be overcome.


Personal Hygiene In Practice


The Skin


As you move around in your daily life, thousands of tiny particles of skin fall off. They are called squames and accumulate to form 80% of household dust.


They are covered with micro-organisms and form a food source for many more organisms.


These squames are a means of passing infection


•      As part of dust they can be airborne for as long as 150 minutes before they land


•      They also provide a reservoir in which micro-organisms can breed.


Their access to the world outside clothing should be restricted.


How can they be prevented from getting out?


Hopefully you would by ‘by covering up’.


In critical areas for hygiene such as operating theatres the surgeon will wear a gown, a head covering, a face mask, gloves, and even sterile wellies.


Clothes and overalls are sufficient in many jobs.


Nurses and domestic staff in hospitals often have to wear tights to prevent shedding of skin from legs.


Uniforms and overalls are therefore used to good effect to protect sensitive surroundings health care, catering, food service – as well as the clothing of the wearer.


The Head and the Hair


Hair should of course be kept clean. In some areas it must also be tied back if long. On top of that, it is often necessary to cover it up.





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Skin from the scalp and hair also fall out at an alarming rate. They also are colonised by micro-organisms and add debris to the environment you are trying to cle4an. Not good!


Now, a silly little hat skilfully balanced or pinned on the back of the head is all but useless to help prevent this. It may be a useful badge of office but so far as hygiene is concerned it is a waste of time.

If covering the hair is important in your job do it properly


In some industries a hair net and a hat are issued.


Hats and hair coverings should be kept clean.


What effect would wearing the same hat for a year without cleaning it have?


The answer lies in the build-up of grease, hair, sweat and skin. Bacteria love it. In the end, no matter how clean your hair at the start of the day, the moment you put a dirty hat on you are contaminated again.




Hands need special consideration in terms of hygiene.


They are directly concerned with working practice.


Long finger nails may be attractive but they can be difficult to work with. They are also more difficult to clean and where hygienic practice is at a premium they are not allowed. Nor for that matter is nail polish because of the risk of it flaking.


Hands may be covered by rubber gloves to prevent transfer of materials, either onto the skin, or from the skin onto a surface. Gloves are relatively cheap and usually available. It makes sense to wear them.


Even if you did nothing with your hands for a day


They would still be unclean by the end!


Hands are rich in sweat glands. They pour salts, acids and grease onto the skin. Micro-organisms love it. They live and flourish and can be passed from one person to another.


Hand cleanliness is therefore vital. But can you get rid of all the bacteria on your hands?


The simple answer is no.


No matter how hard you scrub there will always be bacteria present. It’s perfectly natural for them to be present so don’t worry unduly. Some of them are more deeply





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embedded by the action of scrubbing. Some you may reduce, but the moment you touch your nose or face or hair your fingers become re-contaminated.


One type of bacteria in particular is called Staphylococcus aureus.


A big name for a little bug. In this case the size of the name is proportionate to the problems it can cause.


A certain percentage of the population are healthy carriers. It lives in the nose. It is transferred to the fingers and can then be passed around. It causes boils, food poisoning and wound infection.


In areas where strict hygiene is required, such as on certain hospital wards, a cream can be applied to the nostrils to reduce the incidence of this bacterium. The problem is that it must be applied several times a day.


The Body


Would it surprise you to learn that you are covered in bacteria below the waist?


The main one is called Escherichia coli. It is essentially a gut bacteria. Again it forms part of the natural flora and mostly gives no cause for concern. It is relatively easy to wash from the hands and this should be done each time you visit the toilet.


Problems of sickness can arise if it gets into your mouth and approaches your gut from the wrong direction.


Here is a list of all the things you should do to wash your hands properly.


•      roll up sleeves


•      remove all jewellery etc


•      turn on the tap


•      wash hands under a stream of running water


•      turn the tap off (if possible without touching it)


•      dry the hands (hot air is best)


This probably raises many questions in your own mind.


Rolling up the sleeves is an obvious thing to do to gain access to wrists and even forearms. Jewellery – rings, watches etc – trap dirt and must be removed.


Washing hands under a stream of running water removes more bacteria than using a basin full of hot water. For the same reason a shower is more hygienic than a bath.






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What about soap? Soap helps to remove the bacteria. Liquid soap dispensers are more hygienic than a dry bar of soap left on the sink. Dry soap dispensers are best of all. To a small extent soap kills bacteria.


What about skin disinfectants? These are most often used in hospitals. Hibiscrub is a common example. It contains the diguanide disinfectant, chlorhexidine, in a water suspension. They are effective but can have drawbacks.


The argument for not using them is as follows. The skin is naturally colonised by bacteria, the vast majority of which are harmless. By covering the skin they prevent colonisation by more dangerous forms. Hibiscrub kills of a large percentage of these harmless bacteria and allows colonisation of the skin by potentially more dangerous types. These can then be passed around by skin contact.


What about scrubbing brushes? They do help to remove soil from beneath finger nails. But if a brush has been left damp it will certainly be full of bacteria. In hospitals nail brushes are made entirely from materials which can be sterilised. This is done on a regular basis. However, it takes very little time for bacteria to move in when the brush is left damp.


Turn off the tap? For hygienic reasons the hands you have just washed must not be used. Alternatives


•      spring loaded plunger taps – these provide a metered quality of water which stops when the spring returns the plunger to the up position: once turned on they do not need to be touched again.


•      Lever type taps – the tap is turned on and off by a long lever, operated by either forearm or elbow – no need to touch the tap with clean hands.


•      Foot operated types – perhaps the best of all, certainly the most convenient and easiest to use for hygiene; either a press stud or a pedal keeps the water flowing until the foot is removed.


What if none of these are available? If this is the case then you will have no alternative but to plug the sink and fill it with hot water prior to washing. Again you will not need to touch the tap at the end of the washing procedure.


How to Dry Hands


The balance between hygiene and cost is often weighed before installing a system.


Hot air dryers are good but expensive to install. They take time to do their job. One metered blast may still leave the area between fingers wet. Impatient people don’t like or use them properly.


Paper towels from a dispenser are also hygienic. They are used once and discarded. Bins must be readily available to accept used towels.







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Roller towel dispensers are acceptable. They are expensive. They are usually removed and cleaned by a supplier. They can be a problem when they jam or when the roll runs out with no immediate replacement.


The forgotten enemy! Door handles and hand plates.


Doors are opened and often closed by hand on the way to the toilet. The handles become contaminated. Having washed the hands and dried them you leave. You open the door using your hand and all is lost.


Door handles are a serious threat to hygiene.


Providing everyone washes their hands and the door swings shut on its own then the inner side should be relatively clean. Do not rely on this. A disposable tissue can be used as a barrier between hand and handle. A bin must then be provided for these.


Best of all are self opening and closing doors.


Cuts, Burns and Abrasions


The hands are more prone to damage than other parts of the body. Let’s assume that you have a minor cut on your hand. Which of the following would you do?


•      Nothing. Carry on working. Let the scab form and dry in the open air.


•      Put on a pair of rubber gloves.


•      Seek help from the First Aid Officer who will report, clean and dress the wound with a waterproof dressing.


•      Find a first aid cabinet, clean and dress the wound yourself with a suitable plaster.


The answer is to report to your First Aid point. None of the others are acceptable. Self help does not leave a record of the accident which is important for several reasons. Not least, if the damage progresses due to infection, you will have no recourse, in fact you could be found negligent.




Quite simply keep your clothing clean and wear clean protective clothing. Change it when it becomes soiled.


You should have at least three sets of protective clothing – uniforms, overalls, etc.




Notifiable diseases cause serious illness. They are notifiable because


they may seriously disable an individual in the short or long term





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or         they can spread rapidly through a working population causing epidemics.


As soon as a notifiable disease has been diagnosed it must be reported in writing to the Local Health Authority (Medical Officer of Health). This will be done by the diagnosing doctor who must fill in a special certificate of notification.


This notification is a legal requirement placed on the doctor under the Health Service and Public Health Act 1968 and the Public Health (Infectious Diseases) Regulations 1968.


As a result of diagnosis and notification the individual may be hospitalised. The type of hospital, degree of isolation needed and length of stay will depend on the disease.


For smallpox a maximum security hospital would be utilised. On the other hand although dysentery is notifiable, once you have been hospitalised, you need not be isolated. As a more exotic example, malaria, although notifiable in the first instance, does not imply life long hospitalisation.


The aim of this procedure is to give maximum care to the infected individual and to prevent the spread of the disease by placing him in quarantine if necessary.


It may be necessary to vaccinate the entire family and contacts as a result of diagnosing notifiable disease.


Notifiable diseases are therefore serious. They can kill and may easily be spread.


In the UK the following are classified as notifiable diseases.


•      Acute encephalitis, Acute meningitis, Acute poliomyelitis, Anthrax,


•      Cholera, Diphtheria, Dysentery, Food poisoning (all sources),


•      Infective jaundice, Lassa fever, Leprosy, Leptospirosis, Malaria,


•      Marburg disease, Ophthalmia neonatorum, Paratyphoid, Plague,


•      Rabies, Relapsing fever, Scarlet fever, Smallpox, Tetanus, Tuberculosis,


•      Typhoid, Typhus, Whooping cough, Ebola fever, Yellow fever.


Some local authorities have ordered the reporting of other diseases such as rubella (measles).




Pest control is necessary for all owners and occupiers of premises, not just as a matter of choice, but by law! The Prevention of Damage by Pests Act 1949 requires premises to be totally free from large numbers of rats or mice.




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In areas of food manufacture and catering the Food Hygiene Regulations 1970 require complete freedom from all pests in the maintenance of hygiene.


Local Authorities have the power to close food shops or restaurants which they consider unhygienic due to pests.



Pests include all animals and plants which are living in the wrong place; usually at the expense of man, either directly or indirectly.


Ones that maybe easily come to mind include, rats, mice, ants, cockroaches and birds. However we must not forget the smaller, often microscopic pests such as bacteria and fungi.


We must remember that living organisms only become pests when they are in the wrong environment. For example when particular fungi are used to produce a delightfully stilton or pint of real ale, there is little outcry; however when considering the Dry Rot fungus (Sepula Lacrymans) the word “Pest” has real meaning.


We see animals such as rats and mice as pests for the damage they do and the nuisance they cause. However, the unseen threat they carry is worse. Rats and mice are known to harbour disease-causing bacteria; that is pathogenic bacteria.


These bacteria are present both on and within the bodies of the carrier, and are capable of causing food poisoning and more serious illnesses in man.


So, rats, mice, cockroaches and flies contaminate food on contact.


Animal droppings may be detectable, but other forms of pollution are more difficult, mice for instance are known to have uncontrollable bladders.


So much for the physical damage that pests can cause. But a much stronger factor in the minds of users of your buildings is the revulsion and fear that people feel when confronted with a pest. This leads to loss of reputation on the part of the occupiers and gives rise to public complaint which may involve the public health authorities.


It was around 10,000 years ago that man began to harvest crops and keep domestic animals instead of hunting wild animals and collecting the fruits of plants growing wild. The animals which had lived in the wild on seeds and on the larger animals as parasites now entered man’s homes. They were able to live on much greater stores of food and increased their numbers enormously.


We are still trying to cope with that problem.


Pests can be divided into two groups


•      Opportunist




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•      Synanthropic




These live independently of man, but take any opportunity to feed and survive at man’s expense. Examples are foxes, rats, bats and certain types of ants.




These are pests which rely on man and his environment to survive. They live within the home and complete for the same resources causing conflict with man directly. They include silverfish, fleas, clothes moths, carpet beetles and certain cockroaches. Each of these are considered to be pests because they


•      Carry and transmit disease


This they do through bacteria carried on the body as well as in their excrement.


•      Damage buildings


They cause damage to pipes, cables, textiles, and wood by gnawing. They can cause property to depreciate considerably in value.


•      Spoil food by Contamination


This may lead to food poisoning or more serious illnesses. It also means that food is wasted and has to be thrown away.


Today rodents and insects are said to spoil at least 10% of world cereals after harvest; enough to feed 260 million people, if it could be saved.


•      Cause infestation


Pests reproduce very quickly and can soon overwhelm an area or building.


•      Appear unsightly.


Pests carry a very bad reputation and their appearance can affect staff and trade, especially in the retail food industry.


Animals and plants become pests because they are in search of


•      Food


•      Shelter


•      Warmth


•      Water





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Man’s buildings, premises, and homes can often provide all they need for survival – a tempting option for any pest!




Principal Methods of Pest Control


Pests become difficult to manage or get rid of because generally they


•      Are nocturnal (active only at night)


•      Breed quickly


•      Move quickly


•      Nest in inaccessible places


•      May grow resistant to certain poisons


•      Can survive long periods without food


•      Enter buildings through small holes which are often undetectable


Given these problems for man, there are only certain methods employed successfully in pest control. These are summed up by the initials P.I.R.D.




Good maintenance of buildings is needed to prevent entry by pests. Gaps around pipes, doors, windows, together with damaged gutters, drains, and air bricks should not be allowed to go unattended. They must be repaired immediately.


Incoming goods should be checked to ensure they carry no pests. Dustbins and waste should be stored away from the main premises and particularly from beneath windows.




Regular inspections of buildings should be carried out to identify possibilities of pest entry. These should be thorough and action taken immediately to repair deficiencies in checking procedures or maintenance.




It is essential to ensure that if pests do gain entry, they have no ready-made place to feed and breed. Do not allow build-ups of waste to occur – disposal must be regular and thorough. Stock control together with careful hygiene will deprive pests of food and lodging.




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This may take the form of physical, biological, or chemical means of destruction. The best way to deal with any particular pest will depend on its


•      Origin


•      Life cycle


•      Location


•      Prevalence (the degree to which it has infested the area)


Staff may deal with minor pests on a small scale, but professional help is required where major pests or infestation occurs.




Rodents amount to about one-third of all mammals. They include two of man’s worst pets – rats and mice.


The feature they all have in common is the design of their teeth with two large curved ones in the upper jaw and two others in the lower. These are adapted for gnawing which they do all the time – and on almost anything.




Besides being known as carriers of disease, (the rat flea was responsible for the Black Death – Bubonic Plague,) rats eat and contaminate considerable amounts of food meant for human consumption. They will eat almost anything – even soap.


Their gnawing will cause damage to building structures and equipment – woodwork, plaster board, pipes, containers and electrical installations.


There are two types of rat


•      The Common or Brown Rat


•      The Black Rat


The Brown Rat is the larger, often weighing over half a kilo! It can be identified, apart from the slight colour difference, by the length of its tail. The tail of a Brown Rat is shorter than its body, while that of a Black Rat is longer than its own body.


A Brown rat always remains on ground level and is the commoner of the species.








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The black rat has largely been replaced by the Brown rat but can still occur in some seaport towns. It has the ability to climb and enter buildings by way of the upper floors. It can, for example, walk along an overhead telephone line between buildings.


Rats are nocturnal and also very intelligent; which makes them difficult to control. They are also quick on the ground and can swim. Being very much creatures of habit, they can also prove very wary of baits and traps which appear as an unusual item on their habitual runs.


They are most likely to be found around rivers, canals, rubbish tips and in the country. They require water to be readily available – rats generally need to drink a lot of water.


Life Cycle


Rats breed rapidly. Females can produce up to a litter a month, each of which can consist of up to eight young. The young can become sexually mature within three months. So, in favourable conditions, a pair of rats can produce up to a thousand individuals in one year. It is easy to see just how quickly infestation can occur.


Rats live and breed in warm dark places. Brown rats tend to burrow underground into soft material or loose soil to nest. When Brown rats invade property, they will nearly always come up through a break in the sewers. They often frequent drainpipes feeding on kitchen waste that passes by.


Damage Caused by Rats


They carry disease


Their fur, feet, teeth and excrement are all carriers of harmful bacteria (pathogens) which can affect man; through food poisoning, dysentery, and plague.


Rats and mice can transport Salmonella in their guts and deposit it in their droppings. They also carry bacteria and Viruses which can contaminate food, and can lead to diseases in man such as


•      Weil’s disease A type of jaundice


•      Meningitis – Carried by mice


•      Rat bite fever


They eat and contaminate food


Rats gnaw into most types of food containers; cereals and flour are their favourites but they will eat almost anything.


However they spoil more food than they eat, by contaminating it with their teeth, feet, urine, and droppings. They also ruin packaging and containers with their gnawing.


They damage buildings and installations


They gnaw not only to eat, but also to prevent their fast-growing teeth becoming too long., Thus they may often gnaw for the sake of it.





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Rats can damage plaster, woodwork, pipes, even electrical cables; and can be the cause of subsidence, fires, and general disrepair of buildings.


Signs of infestation


Rats are only usually active during the hours of darkness, so sightings during the day would be a rare occurrence. Apart from actual sightings, there are several factors which indicate whether or not rats are present.


Signs of gnawing and scratching may be present around holes or possibly in certain foods upon which they may have been feeding. They may also leave damaged sacks and containers or spilt food.


Droppings may be found anywhere they have been. They tend to be dark and approximately 10mm long.


Smear marks are usually found on skirting boards or floors along their favourite runs. Smears will be dark in colour, and come from their greasy fur. Brown rats particularly tend to walk close to walls. Because rats are creatures of habit, cleaners may notice, and must report, smearing which recurs after cleaning.


Where Brown and Black rats occupy a building, the Browns keep to the basement and ground floors while the Blacks keep to the upper storeys.


Feet marks may be left in grain or flour on which they have been feeding, or even in dust behind cupboards.


It is worth noting that while mice can be easily detected by their smell, due to their constant trails of urine, rats do not have such an easily recognisable odour.


Control of infestation


Regular inspection of buildings and premises


Considering rats gain entry to a building through some form of hole, it is necessary to cut down their chances. This is done by regular inspection of certain areas

All means of access must be made secure against rats.


•      Doors – to be close-fitting


•      Ventilation bricks and ducts – to be fitted with wire netting with a mesh of 1 – 2 centimetres and the diameter of the wire to be at least 0.7 millimetres (against easy gnawing)


•      Walls – holes and cracks to be filled with cement: where pipes and ducts pass through walls, holes to be covered with a close-fitting plate or filled with netting and cement








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•      Drainpipes – from the roof and outlets from kitchens to be closely inspected as the most likely access points


•      Drains – man-holes to have rat-proof covers


•      Waste pipes


•      Possible burrows in loose soil

Cleaning and storage of materials


The regular cleaning and removal of waste from premises, reduces the attraction for rats to visit.


Food should be stored in closed containers. The design, construction, and fabric of food stores and containers should exclude pests of all kinds. This can be more difficult than it sounds. Pests have an uncanny ability to get into closed containers and rats have a habit of dragging quite large objects around the floor.


Destruction – traps, gas, and poison for rats


Cage traps can possibly be used for rats, but only usually where it is totally impractical to use poisons. Generally poisons are used to control them.


Caution is needed when using any type of poison, especially in areas containing food or in the close proximity to people.


The most common poison used for rats is Warfarin, which can be easily mixed with oatmeal for baiting. It works by preventing the rats’ blood from clotting; they die from internal bleeding.


If taken in continued doses Warfarin will bring about death in rats within 8 – 10 days. So baiting has to be kept up for a minimum period to secure control. It is possible for some rats to build up an immunity to Warfarin, in which cases a different poison can be used such as Difenacoum or Calciferol.


Often when using strong poisons it is necessary to go through a process of pre-baiting, with good food, before baiting with poisoned food. This is because rats are very wary animals and initially will avoid any type of bait – confidence has to be gained. The bait must be laid close to obvious signs of infestation.




Mice are basically the same as rats in terms of infestation and control.


Being a much smaller animal than the rat, mouse- proofing a building is correspondingly more difficult. The mesh netting defences have to be finer. In the case of prefabricated buildings it is important that joints between the outer sheets of cladding are all closed. Mice are excellent climbers and will cope with rough vertical surfaces – timber, brick, cement. They can often find their way up into a cavity wall and reach the roof space.





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A 20 centimetre-wide band of smooth paint positioned 1 metre above floor level can stop mouse gymnastics. Circular metal guards on pipes serve the same purpose. Those attractive, creeper-covered walls also provide good ladders for mice.


Mice are more unpredictable in their behaviour than rats which makes large scale poisoning difficult. Mice are also immune to Warfarin. However they are very nosy creatures and will easily take poison such as Alphachloralose, which destroys their ability to stay warm and causes them to die of hypothermia.


It is usual to use traps as a first preference because dead mice are likely to lie in accessible places and cause an unpleasant smell. The carcases also provide breeding places for blowflies, larder beetles and the like.


Traps are best placed at right angles to the wall with the baited end nearest to it, as the mice will pass along there.


They are not such prolific breeders as rats but do well enough to rapidly become a pest when conditions are favourable.


The adult mouse eats only about 3 grammes of food a day but they destroy a lot more than that through fouling with urine and excrement and by gnawing containers.


They will also damage materials such as timber, insulation, paper and textiles by gnawing.


Their nests are an irregular mess of any available material – cloth, wool or paper for example – placed in a sheltered position.




We have probably had flies as a pest in Europe since men first began to keep their animals indoors during winter. A practice which started around 400BC. There are a wide variety of flying insects which could be regarded as pests


•      Wasps


•      Mosquitoes


•      Gnats


•      Hornets


However, the most common and certainly the most prevalent is the household fly. There are four common species that trouble man


•      The Common Housefly (Musca domestica)


•      The Lesser Housefly (Fannia canicularis)





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•      The Bluebottle (Callifora erythrocephela)


•      The Greenbottles (Lucilia sericata and Lucilia Caesar)


The Lesser Housefly is the type which can be found circling light fittings in many homes. They rely on living in the temperate indoor climate. The female lays her eggs in very damp rotting material at the outflow of the kitchen sink and similar places. The Blue and Green Bottles are larger, make more noise, and tend to come in from outdoors. They are referred to as Blowflies due to their habit of blowing, or depositing, their eggs on exposed meats.


Flies are able to walk freely on surfaces at any angle. This is made possible by feet covered with masses of sticky glandular hairs. It is these sticky hairs which also serve to trap and hold bacteria from any surface on which the fly chooses to feed.


Life Cycle


The complete life cycle of the fly takes place in four, easily recognisable, stages






Each female lays around 900 eggs. Eggs can hatch in 8 – 48 hours depending on the temperature; the hotter it is the faster they hatch. They are always laid in moist, warm places such as pig manure, chicken dung, dead animals, rotting food in dustbins or rich rotting compost.




Maggots are a yellowish-white colour. They are smaller than the Bluebottle maggots, which are used for bait by fishermen. The maggot stage can last between three and a half days and eight weeks; this again depends on temperature but also food supply.




When the maggot is fully grown it seeks a cool dry place where the soil is not too hard. It then burrows deep and changes into a hard shelled pupa. This stage varies between four-and-a-half days and three weeks, depending on temperature.




The fly itself hatches underground and burrows back to the surface. Females are ready to lay eggs after just 2 – 3 days. The whole cycle usually last 2 – 3 weeks; in ideal conditions however it may only take 9 days.


Houseflies breed from June to October. The greatest numbers are found in August and September following what is normally the warmest time of year. During winter



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they may survive as pupa, or through gradual breeding in isolated areas (usually indoors as heat is required).


The damage they cause


Flies are carriers of illness-related bacteria (pathogens) . There may be over 3 million bacteria present on the body and legs of one fly! Flies are a cause of contamination; they progress through a series of stages in order eventually to spoil food.


•      Initially the fly lands on decaying food or excrement to feed or lay eggs. It is here that it collects bacteria on its feet and legs.


•      It carries pathogenic bacteria not only on its feet and legs, but also in its gut (from feeding on the excrement itself).


•      The final stage, and the actual contamination of food, comes as the fly lands on food meant for human consumption.


There are 3 ways in which a fly will actually contaminate food


•      Feet and legs – Bacteria is carried from one feeding place to another


•      Vomit – The fly always moistens its food before sucking it up. Thus depositing bacteria from its last meal.


•      Faeces – Known as fly-specks, which the fly drops whilst feeding. It can do this in excess of 100 times a day.


As a result of their habits flies transmit a wide variety of gastro-enteric illnesses, such as typhoid and summer diarrhoea. In warm countries they can be responsible for spreading dysentery, diphtheria and cholera.


Control of infestation


Infestation by flies is very unlikely to occur, and is rarely a problem. Control is however always necessary in order to avoid the risk of this happening. The basic rules relating to control centre around prevention and not cure. Firstly, consider that flies breed around waste, so there are certain precautions to take


•      Clear waste from premises as often as possible


•      Waste bins should have a good fitting lid


•      Waste bins should be stood on an area of concrete – this prevents the possibility of maggots burrowing


•      Empty bins regularly


•      Wash bins inside and out after emptying wherever possible





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•      Keep bins away from windows


The best way to prevent flies from breeding is to exclude them from the premises in the first place. They are likely to enter through windows and doors. Steps that can be taken to reduce this possibility include


•      Fitting a fly mesh – especially on the window of a food room


•      Fitting extractor fans for ventilation – flies cannot enter through these


•      Hang curtain strips on doorways


•      Install air curtains – a fly-stop air curtain produces a fast air current around the doorway which flies will not cross


Finally, if flies have gained entry to your premises or home, there are several methods of dealing with them


•      Fly paper – unhygienic as everything in contact remains stuck and unsightly


•      Fly sprays - cannot be used where open food or food preparation surfaces are in evidence. Only those containing Pyrethrum are safe in the presence of food.


•      Residual Insecticides – these are painted as a lacquer on the surface and kill the fly as it comes to rest. Most effective in waste areas.


•      Ultra-violet fly killers - flies are attracted by the tubes producing ultra-violet light and are then killed by an electrical charge. The bodies are collected in a tray beneath. These are very effective, but also are expensive. Ultra-violet rays can irritate eyes, so care has to be taken in placement.


There are other types of fly – the Grey Fleshfly, the Vinegar Fly, the Cheese Fly – which contaminate food. But the method of control is the same as for the commoner - seen types above. The Vinegar Fly is probably only remarkable for the fact that it is bred and used in large numbers as an experimental laboratory animal.




Ants are just one of the group of crawling insect pests, which also includes cockroaches, with which we will be dealing with next.


Ants can be found everywhere and something like 3,500 species have been classified. The winged ants seen in the middle of summer are males and the females coming out of the nest in swarms to mate. The males die soon after but the mated queen ants are each capable of founding a new nest. Most of the eggs laid by the queen hatch into worker ants which





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•      Fetch food


•      Keep the next clean


•      Look after the eggs and the various stages of development of the young ants There are two types of ant pest commonly found in Britain


•      The Black Garden ant (Lasius niger)


•      The Pharaoh’s ant (Monomorium pharaonis)


The Black Garden ant lives and nests outdoors, and is not known to carry disease. They forage into buildings in search of sweet tasting things.


They enter through cracks and defects in walls, doors, pipes, and windows.


The Pharaoh’s ant cannot live outdoors in Britain. But it has established itself in many large, centrally heated buildings, where the humidity is high and the food is plentiful. They are essentially protein eaters. It is a small yellowish-red creature readily told from the garden ant.


Life Cycle


The life cycle is similar in stages to that of the fly; it takes the form of




Ant eggs are very small. They hatch into larvae in a period of 3 to 4 weeks.


The larvae are fed by a special secretion supplied by the Queen ant, until they pupate (turn into pupae) and finally emerge as worker ants. They forage for food; this feeds the new larvae emerging from further batches of eggs laid by the Queen ant.


The worker ants do not reproduce. Winged sexual forms are produced each summer; these mate and, while the males then die, the new Queen ants spend the winter underground preparing to begin a new colony in the spring.


The damage they cause


The black garden ant is not known to transmit disease. It is however attracted to food rich in sugar and can prove a pest in the larder.


The Pharaoh’s ant however causes us different problems due to


•      Being a disease carrier


•      Having many Queens to each nest


•      Living only within buildings



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•      Creating new colonies through the Queens spreading throughout buildings


•      Being omnivorous – like us it prefers sweet things but will eat meat, cheese, dead insects and other carrion


•      Being very small (smaller than the Black ant)


It may prove very difficult to eradicate an infestation without specialist help.


Signs of infestation


Here the real indicator of the infestation by ants is sightings. They are totally indifferent to man’s presence and observation – something which can be used to advantage in their eradication.


They can be seen moving in trails to and from their source of food. Black ants soon manage to get a message back to the nest when a foraging worker discovers food!


Control of infestation


As with other pests, prevention is the first consideration. Therefore the maintenance of cleanliness is of the greatest importance. Every crumb of waste should be removed from premises, so as not to attract ants onto the premises in the first place.


Ants can be controlled very easily if their nests can be accurately located. Black garden ants should be traced back to their nest outside where boiling water, poured into the nest, is an effective and cheap solution.


Baits are also available which contain Boric Acid. This is fed to the worker ants who return to the nest and feed it to the Queen and larvae and kill the whole nest as a result. Once the Queen dies there is no future for the black ant colony.


Pharaoh’s ants require different methods of control. In hospitals their small size enables them to penetrate bandages and even to find their way into sterile packs.


Treatment must be systematic. Bands of insecticide in lacquer form (containing dieldrin or chlordane) are applied in a wide vicinity of the area known to be affected. Insecticide needs to be applied to the junctions of walls and floors, around pipe exits, sinks, cracks and the underside of shelves.


A particular way of tracing Pharaoh’s ants nesting points is to lay raw liver poisoned with Boric Acid. This proves useful in two ways


•      The bait is taken to the nest and may kill a good number of ants


•      The bloody liver provides a good indicator (footprints) as to the runs used by the ants and the nest can be located







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Boric acid powder may be pumped into wall and floor cavities. This should give long term protection against ant infestation, at least in those areas treated. If the problem is not easily dealt with in the first instance, it is advisable to seek professional help.




Cockroaches have really been imported into this country. They originate from warmer climates and have become established in Britain, through the years, by being brought in on ships, crates and foodstuffs.


They are creatures used to warm, often moist, conditions. They tend to be more common in commercial and industrial premises than the home. They are most common in multi-storey buildings, such as hotels, apartments and hospitals. Here they get the benefit of central heating together with humidity and access to many rooms.


There are three species which are considered pests to us in Britain


•      Common or Oriental cockroach (Blatta orientalis)


•      German cockroach or ‘Steamfly’ (Blattela germanica)


•      American cockroach (Periplaneta Americana)


The first two, the Common and German, are of the main concern to us in Britain presently.


The Common or Oriental cockroach is the larger of the two, it can reach 2.5 centimetres in length. It is black in colour and is usually found on floors, in cellars, drains, basements and sewers.


The German cockroach is small, yellow, grows up to 1.75 centimetres in length and has 2 black spots towards the font of its body. It is usually found around the tops of walls and along steam pipes in laundries and bakeries.


The male has long shiny wings, but cannot fly. The female is larger than the male, and possesses very short wings. The wings are used for gliding when they jump, say, from table to floor.


The American cockroach is only brought in on ships, in crates and the like; it is not as widespread as the other types. It does however grow up to 4.5 centimetres long.


Although the Oriental cockroach is sometimes known as the Black beetle, it is not a beetle at all, there are certain positive differences between a cockroach and a beetle.


The cockroach can be identified by the fact that they


•      Run fast, with a ‘scuttling’ action


•      Have long Antennae (feelers), which they wave about




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•      Have flattened bodies – to get through fine cracks


•      Have two small tails at the back


•      Give off a very strong smell


•      Are greasy and leathery to the touch



Life Cycle


The Oriental cockroach lays her eggs in groups of 16, encased by a hard dark brown coating. This egg case is then left in a warm place. The eggs take 2 – 3 months to hatch into Nymphs which are very small cockroaches.


They grow and gain their wings through a series of moults, becoming adults within 10


– 12 months. An adult female cockroach will live for 7 months and may produce 5 – 10 egg cases.


The German cockroach differs only slightly in life cycle. Firstly the egg casing can contain in excess of 35 eggs. More importantly, the female looks after the egg case until the eggs hatch (4 – 6 weeks).


The length of the life cycle depends on the extent of the warmth and humidity. These species do not normally live outdoors in Britain.


The damage they cause


Cockroaches, although they prefer sweet and sticky products, will feed on pretty well anything – they are omnivorous. So, their main concern is finding warm surroundings, with a degree of humidity.


They are nocturnal creatures emerging from the narrowest of cracks at night, particularly near warm places, to forage for food.


Cockroaches always contaminate more than they consume by


•      A very distinctive odour


•      Fouling


•      Gnawing, to a lesser extent


Cockroaches cause damage, and become pests to man by


•      Spoiling food by contact


•      Leaving foul smelling excrement and vomit on food and other surfaces




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•      Tainting foodstuffs and materials


•      Transferring bacteria from their bodies to food – they are capable of carrying Salmonella in the gut for months


•      Their unsightly appearance and unpredictability


•      Breeding in vast numbers


The cockroach has been shown capable of carrying a tremendous variety of pathogenic bacteria. It is this fact that makes them often the cause of food poisoning in catering establishments and of cross infection in hospitals.


Signs of infestation


As cockroaches only come out of their hiding places during hours of darkness, they can at first go unnoticed. The Oriental cockroach will very rarely appear in the light, however the German cockroach may be seen in high places during the day.


Signs of cockroach infestation during the day will include


•      Droppings – resemble tiny specks of black plastic, may be seen on floors and walls


•      Vomit – both species have a habit of vomiting; if it was high level it would indicate a german cockroach


•      Egg cases – may be found behind equipment or cupboards; these would indicate oriental cockroaches as german cockroaches carry theirs with them


Night time is the best time to check for infestation, by using a torch. Cockroaches will be active at night and easier to locate.


Favourite places will always be warm and, therefore, if infestation is likely, warm, dark places should be checked first – the grill and behind the fridge.


Control of infestation


As with ants there are certain precautions which can be taken in order to cut down the likelihood of infestation


•      Do not leave food about


•      Clean surfaces and equipment regularly


•      Repair holes and cracks in buildings allowing cockroaches to enter, live or breed








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•      Avoid having dead spaces; behind cupboards and appliances, boxed-in pipes, false ceilings, hollow partition walls and gaps behind skirting boards


Cockroach infestation is a serious problem and is usually best dealt with by professional companies.


Pesticides which can be used in cases of cockroach infestation include lodofenphos, Fenitrothion, Diazinon, Deildrin and Chlordene.


Boric Acid powder and baits can also be used to good effect.

Control of cockroach infestation by the spraying of pesticides has to be very methodically done.


Patch-spraying should not be practised. This just tends to disperse cockroaches and send them elsewhere until the effect has worn off or until they become immune to the poison used. It can very rarely kill a whole population.


The correct programme for the spraying of cockroaches involves these steps


1.                  Mapping – a night inspection to determine the outer edges of infestation


2.                  First Spray (Day 1) – spraying of outer edge of infestation, including sheds and outbuildings; this drives the cockroaches towards the central area of infestation.


3.                  Second Spray (Day 2 – consists of spraying the remainder of the infested area.


4.                  Follow-up Spray (4 months later) – the spraying operation is repeated to kill the newly-emerged nymphs; this is not necessary for german cockroaches since they care for their eggs.


Spraying should always include ands of insecticide being sprayed around free-standing items, door frames and wall-to-floor junctions.


Surfaces should be carefully cleaned down before using them for food again.


Impermeable tiled surfaces can be treated with an oil based insecticidal spray or lacquer, which will provide lasting protection. These should normally be applied by an expert.




Some of the birds that we consider as pests include


•      Pigeons


•      Starlings





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•      Sparrows


They do however only become pests when they invade man’s urban environment.


The feral(wild) or London pigeon is probably the best known pest in the sky to most city dwellers.


Pigeons are descended from the cliff nesting Rock Dove (Columbia livia) hence its nesting habits, which cause it to be found on top of office blocks, public buildings, and under the railway arches.


Other birds came to urban life from the country to look for easier pickings. Gulls however have recently followed the example of the Rock Dove. It used to be considered that the sight of gulls inland meant storms at sea. There are now inland seagull flocks which live around rubbish tips and other sources of food. That’s how we make trouble for ourselves by the way we live!


The damage caused by birds


It would be easy to say that the problem is directly related to the habits of the individual species of bird. This is only partly true. All birds do however present man with certain common problems.


Birds nest in roof spaces of a variety of buildings. In some large food warehouses and stores it is possible that birds are becoming as big a problem as mice. The House Sparrow has been called a winged rat! Sparrows eat foodstuffs and foul them with their droppings. They peck holes in the packaging.


The damage birds cause is


•      Birds’ nests and droppings can block gutters and drains causing water damage to premises


•      Bird droppings carry pathogenic bacteria which are spread readily as excrement dries and powders


•      Birds’ nests contain a variety of other pests (beetles and mites) which in turn may infest stored foods, even after the birds have left


•      Droppings may leave ledges and walkways slippery and dangerous underfoot


Another less obvious danger is that presented by the dead bodies of birds, which remain on premises – in the water tank maybe!


Control of infestation


Birds will usually gain entry through


•      Open doors or windows




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•      Spaces under the eaves


•      Badly fitting ventilators or skylights


•      Damaged roof tiles


To prevent birds’ entry, screens need to be provided to windows and doors.


Eaves should be checked periodically for gaps – if birds can get in, then so can rats! Mesh should be fitted to any gaps as this is more effective than mortar – birds can chip away at mortar.


Always cover water tanks in the roof to prevent possible contamination from bird droppings or even bodies.


Soft plastic repellent jelly can be placed where birds alight and nest. It will effectively repel Pigeons and Starlings, and does no harm to the birds or the building. Wires and netting may also be used to keep birds away from roosting points.


Broadcasting the alarm calls of particular species of birds is also employed by specialist companies.


Bird control contractors can be used where pigeons become a real pest. They are empowered to destroy pest birds, and do so with the use of stupefying bait or even cage traps.




We all now know what pests are. But what about pesticides?


We know that they are designed to destroy pests. We know that they are poisons and should be treated with care. But how do we recognise them if we come across them and what precautions should we take.


The name of each pesticide is based on its target area, such as


•      Insecticides – for controlling insects


•      Herbicides – for controlling weeds


•      Fungicides – for controlling fungi


There are also Bactericides, Rodenticides, Miticides, Nematocides, and Molluscicides.


Despite all the methods of physical or biological control which exist, pests are usually subject to some form of chemical control. Pesticides come in a variety of forms


•      Powders






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•      Oil based spray


•      Aerosol


•      Puffer pack


•      Bait


•      Smoke (fumigation)




There are guidelines to follow in the use of pesticides.


Chemical-bases agents of all types carry instruction labels for the user’s benefit and protection. General rules include


•      Before using any pesticide, read the instructions on the label, and carry them out to the letter


•      Store all pest control chemicals away from children and pets


•      Never transfer pesticides to different containers – if it is absolutely necessary, then always label the new container clearly and boldly


•      If liquid pesticide is splashed, wash off immediately


•      Wash hands after use and always before eating food


•      Never apply insecticides to the fur of animals unless specifically prepared for this purpose – buy the correct proprietary brands for the purpose


•      Destroy by burning, or bury deep, the bodies of rats and mice killed by rodenticides


•      Residues after usage should always be disposed of carefully – wash the containers well and use plenty of water to rinse


•      Do not spray or use near naked flames as many insecticides contain flammable solvents – open windows and doors to improve ventilation when using anything solvent-based


•      Avoid inhaling vapour or fumes from any chemicals used


There are a variety of Acts which control and regulate the use of pesticides. Apart from Government, there are various bodies and guidelines which control the usage and administration of pesticides. These include the British Pest Control Association.







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It is always important to remember that the range of pesticides available to individuals is limited. Whenever there is a case of heavy infestation it is often wise to call upon professional services. They not only have access to a wider variety of pesticides, but also have more equipment and experience.


It is safety that is of prime concern- pesticides should kill pests and harm nothing else.


It is perfectly possible however that cleaning operatives may come across baits, traps and sprayed areas in the course of their work. This should not happen without their being aware that an area is under treatment and what precautions they should take. To make sure that is always the case, the approach to pest control must involve everybody working in a building.




As suggested the best methods of pest control are preventative. If we can remind ourselves of the parts of a pest control system


•      Prevention


•      Inspection


•      Restriction


•      Destruction


All of these elements have a lot to do with the cleaning services. As the people most often working unsocial hours, cleaning operatives are working when the pests are working. Since the operatives are cleaning surfaces at all levels, they are most likely to see telltale trails, smears and droppings.


Because of the need for detective work to establish the presence of pests before they are left alone to become an infestation, it is widely accepted that pest control routines must be integrated into everybody’s work.




It should be part of every cleaning operative’s task to report damage to the fabric of the areas in which they are cleaning. Never mind that they never do anything about it


– the first step to getting something done is to keep up the pressure.

Prevention means observation and report


It makes the cleaning job easier if surfaces are continuous and well maintained; that’s right in line with the need for pest containment.


Don’t forget either that point about the sheer cleanliness of any area removing the opportunity for food from pests. It has been said by the distinguished authors of a




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book on wild life in the house and home that the daily use of the vacuum cleaner is the most important method of keeping pests under control.






A detailed inspection by one pair of eyes once in a while, is not nearly as good as the continuous observation of a substantial number of people. Cleaning operatives particularly need to be trained to recognise pest signs so that action can be taken before the problem is so obvious that extreme measures have to be taken to cope with it.


We have referred to the greasy trails left by rats along the walls and floors of their runs. There are other signs


•      Droppings


Cockroach droppings look rather like mouse droppings but a bit smaller


House mouse droppings are cylindrical and usually about 6 millimetres long and 2 millimetres across


Rat droppings are cylindrical and, in the case of the adult rat, about 17 millimetres long and 6 millimetres across


•      Footprints


Insect tracks are difficult to identify because they have six legs


Mice and rats have four distinct toes on the forefoot and the much larger hind feet have five toes


•      Smell


Flour mites give a sickly, sweetish smell to grain and flour


Cockroaches have a distinctive sweetish smell


Mouse urine (a plentiful commodity) has a strong smell


Cleaning operatives also need to know what methods are employed to control pests and what they look like in place. Not only from a personal safety point of view, but also so they don’t interfere by cleaning or clearing away


•      Insecticidal lacquers


•      Traps






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•      Baits








Here too the cleaning service has a part to play. If prevention by cleanliness and reported observation fails, then efforts may need to be re-doubled


•      By replacing routine cleaning by deep-cleaning to eliminate food sources for pests


•      By alleviating maintenance shortcomings in the short run by extra drying and sanitising of areas




Depriving pests of food and water is the surest way to their destruction. Cleaning techniques which leave areas, and the equipment that cleaned them, clean and dry, is prevention and destruction.


Otherwise the cleaning service’s job is to keep itself informed of destruction processes going on and make sure it doesn’t interfere with them.




There’s no apology for adding a fifth stage in the pest control system. That system depends on information about pests


•      Sightings


•      Breakdowns in defences


•      Action taken against infestations


The cleaning manager needs to see that the Pest Control Book gets some entries from the cleaning service. And that it is consulted regularly to see what pest control treatments are planned and in force.


The building’s Pest Control Officer needs information to guide action. For this there are three important sources


•      Details of breakdown in defences – broken or missing drain covers, missing dustbin lids, leaking taps or sink bends, broken pipe flanges into floor ducts


•      Details of sightings – time, suspected pest, location and evidence details


•      Action taken – reported to pest control operative, baits removed on instruction, reported to maintenance



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All of these should be recorded. Details of sightings from a variety of sources is important evidence for action, but it has to be built from a record over a period.





The subject of waste management has become more and more important in the last twenty years. Our society produces more waste than ever due to


•      Modern packaging methods


•      Hygiene requirements in food service and retailing


•      The increased use of disposable items ranging from throwaway razors in the home to disposable needles and syringes in the hospital


•      The increasing number and size of newspapers and magazines


Unfortunately this has been accompanied by carelessness and indifference on the part of the general public as to where they dispose of waste. People of all ages seem to throw their cigarette ends and general rubbish out of cars as they drive without a second thought. The streets of any residential area are littered with crisp packets, sweet wrappers and the like discarded by passers-by.


At the same time the Local Authorities have been finding waste clearance an expensive and difficult matter because of


•      The sheer increase in volume


•      The number of parked cars in streets obstructing sweeping machines and even defying the efforts of the one-man-power dust cart


•      The increase in the variety of waste – some of it dangerous, like aerosol cans


•      The desire to re-cycle as much waste as possible


•      The danger of land-fill tips generating methane gas and giving rise to land-slip problems when the land is reclaimed and built on


The Cleaning Service and Waste


Our concern as cleaners is not in the grander issues however. We are principally concerned with waste as a cleaning and hygiene problem in and around buildings. But we all need to understand that waste is a national problem which will not be solved by the great and the food or any marvellous national plan. It’s a matter of


•      Getting our own areas organised for efficient waste disposal





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•      Building in the hygiene requirement to the collection and storage of waste


•      Being aware of the health and safety requirements for dangerous or potentially dangerous waste items


•      Playing our part in persuading the users of buildings to be less careless in littering their work areas and putting the wrong kinds of waste into containers which aren’t designed to take them


You probably already know that up to 40% of an office cleaner’s job can consist in emptying waste bins and removing the contents to a disposal point. When you add to that the amount of litter and dirt which cleaning removes, we have a powerful interest in the subject of waste management.


Then too there is kitchen waste to be considered, not forgetting that eating at desks has become commonplace. The absence of a kitchen in a building doesn’t mean that there aren’t food residues to be disposed of.


Types of Waste


Each type of waste will have its own hygiene or other health and safety risks which we’ll discuss later. In the meantime what sorts of waste do we handle and where do they eventually go to. A broad summary is


Type of Waste




Oil, grease or wax impregnated

Incinerated or removed by specialist contractor



Sold as swill, incinerated or removed by local





Bottles, cans, old wiring, plastic

Removed by the local authority



Must not be incinerated because of the danger of



explosion. Removed by local authority


Paper, cardboard, rags

Often has a salvage value and needs to be stored



separately for removal. Otherwise incinerated or



removed by local authority



Confidential papers placed in padlocked bags and



removed by specialist contracts who guarantee



destruction under conditions preserving an



organisation’s secrets. Sometimes shredded within



the organisation and disposed of as ordinary paper





The table covers most types of domestic and commercial waste. There are other types with which we may be concerned.




This comes from hospitals, surgeries and clinics and covers


•      Soiled dressings, swabs and plaster


•      Disposable scalpels, syringes and needles






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•      Disposable bed linen, couch covers and the like


All of this must be regarded as infected and handled and stored separately from other kinds of waste.


The sharp items will be placed in a special sharps box to prevent accidents in handling the waste.



Any clinical waste container must be handled with care in case an error has been made in disposing of sharps


Other items will be placed in coded bags according to the disposal policy of the unit.


All infected waste must be incinerated.




This may include anything which is a waste produce of an industrial process


•      Scrap plastic, metal, wood and so on


•      Oils and cutting compounds


•      Waste including dangerous chemical elements or radioactivity


Some industrial waste is recycled – oil for example is tanked away by specialist contractors who process it to remove contamination.


The dangerous waste is subject to Government regulation as to storage and disposal. The regulations are backed up by regular inspection and licensing of premises.



Waste Collection


The containers used to hold waste will vary according to the type of waste and the kind of establishment that generates it. However there are some general points to be made


•      Infected and dry kitchen waste needs to be kept in bins with a well fitting lid lined with a disposable sack – to prevent contamination of the surroundings and to keep out pests


•      Bins and other waste containers must be cleared before they are two-thirds full


– to avoid overflows and enable liners to be securely closed


•      Waste containers should be of sufficient size or in sufficient numbers to contain the waste generated between clearances to waste disposal




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•      Waste clearances should be organised at the right frequencies according to the demands of each area


•      Containers set aside for particular classes of waste must be clearly labelled or colour-coded to make sure they can be used correctly






Kitchens produce wet, dry and solid waste.


Wet waste can be put through a waste disposal unit as it is produced and passed directly into the drains. Failing that it needs to be kept in containers with a smooth impermeable finish which can be cleaned efficiently.

Containers must be kept covered at all times


Wall-mounted sack holders with close-fitting lids and sacks of plastic or waterproof paper are best for small dry waste items and cans and bottles. Since this waste is also contaminated with food particles it must be sealed and removed to the waste area when each sack is no more than two-thirds full.


Dry cardboard and other outer packaging should be transferred to the waste area as it is produced.


Hospitals and Clinics


We have already discussed much of the requirements of these areas. However since a hospital also has kitchen, offices, workshops, stores, remedial units and transport facilities it is the variety of waste which is usually the problem.


Much of it arrives at the collection and disposal service from different areas which operate their own waste control disciplines. What can be forgotten is however that the portering staff also need to know what the rules are so they can handle it safely and dispose of it correctly. A clear waste management policy and staff training in procedures is essential.


Either separate types of sack holders for different wastes or different coloured liner sacks are used to distinguish the type of waste and indicate the precautions necessary for handling.


Close fitting lids are needed for clinical waste containers and containers used for transport to the waste holding area should have the same. Sacks for general waste need to be sealed and their transport container should also have a lid.


Hotels and Offices






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General waste is usually bagged. The waste containers in which it is collected are usually lined to speed up collection and to provide a hygiene precaution against the variety of items which may have been disposed of by guests and office workers.


Office and hotel waste is more likely to contain tobacco ash from smokers. The commonplace caution of the ‘60’s and ‘70’s of having metal waste bins to contain the fires caused by careless smokers has declined with the declining number of smokers of the ‘80’s. Nevertheless there are still sufficient addicts around to present a hazard. Ashtrays should be emptied into metal bins, and not into paper or plastic sacks, as a precaution against smouldering embers bursting into flames.


The Design of Waste Holding and Disposal Areas


We have discussed the part that uncontrolled waste can play in providing pests with a comfortable life cycle. You’ll remember also that a powerful requirement for pest control is the fear and revulsion that people fee for them.


Bad waste management creates the same kind of reaction – even from the kind of people who never bother about controlling their own litter. Overflowing bins with litter blowing about and generally untidy waste areas are taken as a sign of careless and indifferent management.


If you want a good system of waste management then the waste holding and disposal area needs to be designed for hygiene. That’s the hygiene of the whole site of course


– not just the waste area.


•      It must be big enough to take the waste for the whole site; and then a bit more to allow for strikes, bank holidays and other variations from normal waste removal service


•      It needs a waste bin cleaning area with


Plentiful hot and cold water supply


A pressure lance with detergent injection or a steam cleaning machine


Drainage with the surrounding area in well-finished concrete with adequate falls to the drain to prevent the collection of pools of water


Sufficient hose lengths to enable the whole waste area to be washed down once a day


Raised grids for the binds to be upended to drain and dry before being returned to use


•      The whole of the bin handling and storage area needs to be concreted with adequate drainage and falls to drains – this includes the access for the delivery and removal service; it is here that spills will occur which need to be cleared up promptly and hygienically; a hard continuous surface will deny flies and other pests the opportunity to burrow and continue their life cycle





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•      All bins must have well-fitting lids which are included in the bin cleaning programme


•      If the whole area is under cover, then the fire resistance of doors must be at least half-hour and the building must be vermin-proof


•      If the whole area is not under cover then there must be cover for any ordinary dustbins in use to protect them from the weather and from being blown over in windy weather


•      The waste area must be divided and signposted according to the classifications of waste and its disposal arrangements set out in the waste management policy


•      A vehicle washing bay should be provided for trolleys and vehicles used for the transport of waste around the site


•      The site should be as far removed as practicable from the other buildings on the site


You will see that the emphasis is on scrupulous cleanliness – this is more certain as good hygiene practice than the employment of disinfectants which can lead to complacency about hygiene standards.


Waste Management Policy




Sections 2 and 3 of the Health and Safety at Work Act 1974 impose on employers a duty to do what is reasonably practicable to dispose of waste in a way which does not endanger any person.


Section 30(1) of the Control of Pollution Act 1974 defines waste as including any articles and substances which are



•      Scrap material


•      Effluent


•      Unwanted surplus substance arising from any process


•      Any substance or article which needs to be disposed of as being broken, worn out, contaminated or otherwise spoiled.


Explosive and radioactive substances are dealt with under their own Acts – the Explosives Act 1875 and the Radioactive Substances Act 1960.


Collection and Disposal






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The Collection and Disposal of Waste Regulations 1988 define wastes that can be treated as household, industrial and commercial waste. The regulations provide that mineral or synthetic oils and greases, asbestos and clinical waste may not be treated as household waste. Special arrangements are needed for their collection and disposal.


Other parts of the Regulations deal with licensing the use of plant and equipment to dispose of waste.


The Control of Pollution (Special Wastes) Regulations 1980 cover wastes that are dangerous to life or have a flash point of 21◦C and above. Prescribed medicines are an example.


Waste Disposal Sites


The Control of Pollution Act requires that sites used for waste disposal are licenced with a Waste Disposal Licence issued from the Local Authority.


Where a contractor is used, the producers of waste must satisfy themselves that the contractor is competent and the site to be used is licenced and suitable for the waste.


Anyone who acts contrary to requirements of these Acts and Regulations may be liable to a fine of up to £2,000 and/or imprisonment for up to two years.


Setting up a Waste Management Policy


The legal requirements we have just covered show the need for an organised approach to waste collection, handling and disposal.


Employers need to consider


•      What wastes they are producing


•      Whether any of them require special measures because they are subject to regulation


•      From a purely economic point of view, whether any of them have a salvage value which makes it worthwhile separating them from other waste to sell them off – rags, paper and cardboard, metal and oil are the commonest examples


•      Whether, on the particular site, there is potentially a hazard to people from any kind of waste making it necessary to adopt particular methods or precautions with it


There is also the requirement under the Health and Safety at Work Act to provide an organised system of work; and to keep the premises clean. These provisions require the employer


•      To clear waste systematically






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•      To clear it as frequently as is necessary to keep premises unlettered and safe to work in


•      Not to cause a hazard in the waste clearance process itself


If there are catering arrangements in a building, then the Food Hygiene Regulations and the Pest Act will require


•      That food waste is kept and cleared so that it is not a source of contamination or infection


•      That pests are controlled and cleared – their feeding and breeding environment being the presence of waste


The Department of the Environment issues publications to guide employers in various aspects of waste. These cover, for example


•      Pesticides


•      Solvents


•      Mercury


•      metals


•      wood preservatives


•      asbestos


•      preparation of waste disposal plans


Waste Disposal Authorities (Local Authorities) are also an expert source of guidance.


A successful waste management policy will therefore


•      identify the waste produced by the organisation


•      define how it is to be Collected


Handled Stored Disposed of


•      say how many and what type of waste collection bins are to be provided for each work area and the frequency of collection




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•      provide training for staff producing waste in correctly disposing of it and follow up to ensure that procedures are being followed


•      train the waste handlers in safe methods of clearing the various types of waste


•      define the requirements for a competent contractor to clear waste from the site


•      define the hygiene routines to keep receptacles and transport in a clean, odour-free and safe condition


•      provide for inspection and enforcement to maintain standards by way of linkages to staff disciplinary codes and contract conditions


Remember pest control and waste management is not somebody else’s responsibility


– it is the responsibility of everyone working in a building.


It is particularly important that cleaning people feel themselves to be involved and have the information necessary to contribute.


Pests are very difficult to control once they have reached the numbers which mean an infestation. Prevention is better than cure. Prevention requires that people are aware of the dangers and have a system into which they can report for action to be taken.


Waste management is of even closer interest to cleaners, if it isn’t done well they will have to clean up the mess. But it is also very much tied into the prevention side of pest control.


Supervisors and managers of cleaning services have a real part to play and need to act positively to make sure that their service is involved and effective.


Waste Management Equipment


In addition to the humble bin, which itself has undergone a lot of re-design in recent years, there is a variety of equipment to assist site handling and storage of waste. There are also devices to prevent undesirable effluents reaching drains.




These were once the thing for rubbish collection in large buildings. Their most notorious form is in large blocks of municipal flats. The equivalent of a small lift shaft rises from the ground floor to the top floor of the building. Hatches are provided at each floor level into which refuse, hopefully bagged, can be put to fall into a large, wheeled rubbish container in the bottom of the shaft.


Chutes have fallen into disfavour because of


•      abuse – people putting old chairs and the like into the hatch which jam in the chute and cause a stinking mess for the caretaker to clear




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•      the piston effect of falling debris pushing contaminated air through the exit door of the chute to the detriment of passersby – laundry chutes were abandoned in hospitals following a study of their cross infection effects


•      hygiene problems – chutes may be fitted with in-place spraying systems for cleaning but the contamination caused by rubbish needs vigorous scrubbing for removal followed by drying which was not provided for.


Disposal Units


These are fitted to the waste outlets of sinks to grind up food waste and flush it down the drains. Their successful operation requires


•      a good flow of water throughout


•      regular cleaning and deodorising


•      selection of the food residues the equipment will cope with – string, gristle, sinew will wrap themselves round the grind impeller and fatty substances tend to form into a ball




There are many designs of these in a variety of sizes. Their common purpose is to crush rubbish into a smaller compass so that it can more easily be handled and stored. The rubbish is placed loose in a chamber and a ram compresses it into a block.


Sometimes the compactor acts as a baler for cardboard and paper, not only compressing it but binding it ready for removal.


Glass Breakers


These are designed to safely break waste bottles, lighting tubes and other glass items into glass cullet which can be sold or otherwise disposed of. The amount of lass waste needs to be high to make this worthwhile.


Petrol Interceptors


It is illegal to discharge any inflammable liquid to the drains. In garages and other areas where this is likely to be a risk, an interceptor tank is fitted. This traps the petrol and allows it to evaporate off.


Grease Traps


These are commonly fund in kitchens. The grease enters the trap and sinks onto a perforated tray as it goes sold under the action of cooling water in the trap chamber.








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The tray must be removed and cleaned not less than once a week.





Monitoring is usually taken to mean the inspection that a client carries out on cleaning work done under contract, either in-house or by an independent contractor.


Random Inspections


For a random inspection there is no notice given that a particular area or environment is to be examined. The manager or supervisor simply turns up and checks the standards of cleanliness and hygiene.


Such inspections may hope to find out the usual standard for the time of day or season.


The results of such an inspection and further action to be taken, if any, should be carefully considered. The conditions under which the inspection were carried out may not have been usual. Like any other quality check, it is best carried out immediately after cleaning has been done.


Notified Inspection


Prior notice is given that an inspection will or may take place.


The exact time and location may be given. Alternatively a more vague time scale may be stated, such as, ‘sometime next week’ or ‘sometime tomorrow’.


It is as well to know or find out


•      why the inspection is being done


•      by whom


•      for whom


•      what further possible action can arise out of it.


One type of inspection may for example be a formal inspection of the hygiene standards. This may be a far different event from a routine quality check.



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As for the psychology of inspections, it is expected that people prepare for inspections. Extra attention is given therefore to the finer points during the inspection. If, after due notice and preparation, areas are found to be inadequately cleaned, then it will probably be assumed that, on a more routine level, they are cleaned rarely if ever.


Inspections may simply be notified for the sake of convenience. An inspection may just be to find out the level of bacteria in the air. The placing of personal or collective responsibility or blame may not be the intention of the inspection. You still need to know why there is to be an inspection.


Evaluation of the Cleaned Result


Does it look clean?


Is there no visible soiling on surfaces areas or articles?


To test this a clean white tissue can be taken and rubbed on the surface. If it is as clean at the end as it was at the beginning then you can be satisfied.


Window sills, tops of cupboards and ledges are often wiped with a finger to make sure there is no soil present. Desk slides, chair spiders, chair rails, tops of doors, skirting tops are favourite ‘trap’ areas inspected to find out whether thorough cleaning is being done routinely.


Does it smell clean?


Absence of unpleasant odours coming from a surface article or area.


An unpleasant smell may indicate poor cleaning technique, misuse of chemicals or of equipment.


Does it feel clean?


When a finger is rubbed over a surface does it feel greasy? This should not be so, unless the grease is paraffin oil for the purpose of dust trapping.


Does it compare well with other similar areas?


A comparison between two similar areas post-cleaning will test consistency of standard. If one is clearly less clean, then methods, materials and staff may need to be looked at.


Reduction or increase in problems


Potential problems are affected by the nature of the location where cleaning is done and the processes which are carried out there.


Your indicator may be a rise in the rate of staff or patient infection, spoiled food or computer failures.



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If the unsatisfactory event can clearly be identified and connected to a change in cleaning methods, materials or staff then a more thorough investigation may be needed to pinpoint and remove the problems.


A rise or fall in bacterial or particle counts


This kind of soil is invisible. It may be related t a rise or fall in other problems or improvements in the cleaning situation. This depends on the degree of change and the type of contamination involved.


Monitoring is by agar settle plates, contact plates or air samplers. Levels are recorded and tracked on a graph to detect variation.


If an upward trend is noted and investigation may result. This may well embrace cleaning methods, materials and staff.


The conclusion to the investigation may require a change in cleaning frequency, re-training of staff or a change of methods and materials altogether. It could be that the methods used, although thorough, are ineffective against the particular contamination or surface type.


Time and effort


The time and effort put into cleaning and maintenance do not always reflect the standard attained.


For example, just because a man spends six months painting a picture does not make it a work of art, or even competent for that matter. So too, because an operative is endlessly working at the favourite job and skimping the others; or using their favourite technique rather than the one you laboriously taught them.

Time and effort must be used effectively and competently.


Method, materials and training are the key.


Evidence from pests


It is often true that two or three pests, such as cockroaches, spotted during the day means many more exist in hiding.


Good housekeeping and standards of hygiene will reduce pest problems. To the greatest extent, the presence of pests is a poor reflection of hygiene standards.














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