Home > Procedures and Methods of Cleaning

Whatever the location, industry, soiling type or circumstances, cleaning and disinfection comprises six basic stages:

• pre-clean: sweeping, wiping or scraping off loose debris, pre-rinsing and/or pre-soaking;
• main clean: applying detergent and loosening of the main body of dirt;
• intermediate rinse: removal of loosened dirt, chemical neutralisation of cleaning agent residues;
• disinfection: destruction of residual micro-organisms;
• final rinse: removal of disinfectant residues; and
• drying: removal of final rinse water.

In the absence of visible soiling, the pre-clean may be omitted. The main clean and disinfection can take place in combination using specific chemicals known as sanitisers. (This becomes a three-stage process, i.e. main clean/sanitise, rinse and dry. Where there is no risk of taint the rinse may be unnecessary.) Drying can either be natural, as in air drying, or physical, using disposable paper towels, hot air or a clean dry cloth. Cleaning and disinfection solutions should be changed regularly to ensure the chemicals are working effectively and recontamination of surfaces and equipment does not occur. Cleaning equipment used for raw food areas should not come into contact with that used for ready-to-eat foods and all equipment should be cleaned and disinfected prior to storage.

Manual equipment and utensil washing (clean out of place):

Manual dishwashing is only recommended for washing-up in catering premises, public houses and retail outlets selling high-risk foods, when suitable dishwashing machines are not available. It also applies to food-processing, packing and distribution plants where small items are handwashed. Thermal disinfection is most effective if double sinks are used but a suitable chemical disinfectant, such as hypochlorite in a tablet form may be used, to minimise condensation problems and health and safety risks. However, the rinse water should still be hot enough to allow air drying. The full, six-stage procedure should always be followed:

• remove any heavy or loose soil by scraping and rinsing in cold water;
• place articles in the first sink in detergent solution at 53°C to 55°C, scrub with a nylon brush and/or wipe with a clean cloth to loosen dirt residues, if temperatures are too high, e.g., 60°C+, proteins may be baked on and it will be too hot for hands;
• re-immerse in the first sink to wash off loosened dirt;
• place articles in the second sink to rinse off detergent;
• leave for sufficient time at a high enough temperature to ensure disinfection and rapid air drying, for example, 82°C for 30 seconds. Dilution (large volumes of water in sinks) will also aid disinfection. Baskets for disinfecting purposes should be maintained in good condition and inspected regularly. They should be loaded so that all surfaces of crockery and equipment are fully exposed to the rinse water. Hollow items such as cups should be placed on their side; and
• remove articles, allow to drain and evaporate dry on a clean, disinfected surface.

A rinse aid may be added to the rinse water to promote smear-free drying. Items should then be removed and stacked in a clean, protected area ready for re-use. Containers and pans should be stored inverted to minimise the risk of contamination.

Mechanical equipment and utensil washing:

Mechanical dishwashing is preferable to, and often more economic than, manual washing, provided the machine is used according to the manufacturer’s instructions. Machines, in addition to cleaning, are also a highly efficient means of disinfecting small items of equipment and should be used for articles such as the removable parts of slicing machines, polypropylene chopping boards and other items which come into contact with high-risk foods, provided that no damage to the item will result. The sequence is as follows:

• remove excess food into suitable waste bins; if necessary pre-soak or spray, unless the machine is fitted with a pre-wash cycle;
• pack articles in a neat, orderly fashion so that items do not overlap, place racks in the machine and operate the wash cycle of hot detergent solution (49°C to 60°C), unless automatic;
• operate the rinse cycle (82°C to 88°C), with injection of rinse aid; and
• remove racks, allow cleaned items to drain and evaporate dry.

As a rule-of-thumb guide to the efficiency of a machine, if items coming out are too hot to handle and dry rapidly to a clean, smear-free finish, then the machine is operating correctly. Better hygiene results are usually obtained from mechanical washers compared to manual washing because:

• machines use higher temperatures for washing and rinsing;
• stronger detergents can be used;
• there is always a hot water disinfection stage, unlike single sinks;
• the water does not get cooler or dirtier with use; and
• air drying of crockery and utensils is more likely.

To get the best results mechanical washers, such as dishwashers, should be well maintained and cleaned regularly. Food debris should be rinsed off before loading and the machine must be packed correctly and not overloaded.

Cleaning a cooked meat slicing machine

Pre-clean:

• switch off power socket and remove the plug;
• set the slice thickness control to zero;
• dismantle the machine, pre-clean and pass removed parts through the dish[1]washing machine. Alternatively, thoroughly clean removed parts in a sink using detergent and hot water at 55°C and then disinfect in second sink or using a chemical disinfectant. Where the machine is of a type that has a removable blade, a blade guard must be fitted before the blade is removed. Cleaning may then commence, with the proviso that no person may clean a slicer or other dangerous machine unless they have reached their eighteenth birthday and have been properly trained; and
• clean and disinfect the machine carriage using clean cloths, taking particular care with the electrical parts.

Post-clean:

• reassemble the machine very carefully to avoid possible accidents;
• disinfect parts handled or otherwise contaminated;
• check the guards are properly fitted, reconnect the power and switch on the machine. Test run to check safe working. This procedure is vital because accidents have been caused by guards having been improperly fitted after cleaning. If any adjustments have to be made, the machine should be switched off and disconnected and the test run repeated;
• switch off the machine, disconnect the plug and cover with a freshly laundered tea towel or other suitable covering; and
• supervisor to check.

Clean in Place (CIP):

CIP (Clean-in-Place) is a method of cleaning the interior surfaces of pipes, vessels, and processing equipment without disassembly. CIP has replaced manual cleaning in industries that require frequent internal cleaning of their processes. Industries that require high levels of hygiene include dairy, beverage, brewing and many food processors. The benefits to industries that use CIP include:

• cleaning is faster as equipment does not need to be dismantled;
• less labour is used to dismantle equipment, reducing costs;
• can be repeated frequently as required; and
• less risk of a chemical hazard to operatives.

To ensure the effectiveness of CIP, equipment must be carefully designed. For example, there must be no inaccessible crevices and pockets in pipework that could trap debris and bacteria. The process involves passing non-foaming detergents and disinfectants through processing equipment. The combined effects of solution turbulence, chemical energy and heat remove solid debris and micro-organisms from food processing equipment.

Cleaning schedules:

Cleaning schedules or scheduled cleaning procedures are essential to ensure effective cleaning, and will assist a due-diligence defence. They must be clearly and concisely written, without ambiguity, to ensure that instructions to staff are easy to follow and result in the objective of the cleaning schedule being achieved throughout all areas of the food business premises.

Written schedules should specify:

• what is to be cleaned, e.g., ceilings, walls, floors, working surface, equipment, chopping boards, etc.; who is to clean it;
• when it is to be cleaned (frequency);
• how it is to be cleaned;
• the time necessary to clean it;
• the chemicals (and dilution), materials and equipment to be used, and the contact time necessary;
• the safety precautions to be taken;
• the protective clothing to be worn; and
• who is responsible for monitoring and recording that it has been cleaned.

Supervisors should ensure that, after each cleaning session, all items specified in the schedule have been cleaned satisfactorily and any equipment that has been dismantled is safe to use.

Clean as you go

Items like knives and food preparation surfaces are likely to be contaminated with micro-organisms. These items should be cleaned and disinfected throughout the work period. Staff should implement a ‘clean-as-you-go’ policy by clearing away and cleaning up as they work, and immediately after completing a task.

The role of the supervisor in cleaning:

Effective planning, supervision and organisation is required to ensure coordinated and satisfactory cleaning. Supervisors must ensure that there are always sufficient cleaning materials and suitable facilities available and staff are given clear instructions and/or training on cleaning and using cleaning equipment. It is essential that staff fully understand instructions and procedures with regards to cleaning and disinfection, in particular with regards to dilution, application methods and contact time. Providing measuring containers and identifying ‘fill’ levels on buckets and other vessels will assist staff to ensure the effectiveness of procedures. The supervisor should check that staff clean and correctly store cleaning equipment after use. Equipment should be checked for damage and items like worn brushes, for example, should be replaced. Staff can be motivated to clean if supervisors lead by example, demonstrate the correct way to clean and disinfect and monitor cleaning activities. Praise should be given for high standards and disciplinary action may be appropriate for unsatisfactory cleaning. Competency testing may be used to test knowledge and satisfactory implementation. Posters and notices may also be useful to encourage cleaning.

Supervisors will need to monitor the standard of cleaning by careful observation/inspection and occasionally using swabbing techniques such as ATP (adenosine triphosphate) or Vericleen which indicate the presence of food, dirt or bacteria in a few minutes and microbiological swabbing which provides results in several days. Cleaning schedules should also be checked to ensure they are being signed by the cleaner as they may be required for a due-diligence defence.

Regular auditing of the cleanliness of premises and equipment, including checking that cleaning schedules have been signed off by the supervisor will be necessary to verify that cleaning is effective. Monitoring the amount of cleaning chemicals used each week may also indicate the effectiveness of cleaning. Too little spent on chemicals indicates ineffective cleaning and too much may indicate wastage.

If the standards of cleaning are unsatisfactory the supervisor may need to:

• provide better training/instruction;
• provide more resources (time and/or materials/chemicals/equipment);
• provide closer supervision and increase frequency of monitoring;
• motivate staff to improve standards; and
• discipline staff for poor performance

In-house and contract cleaning:

Food businesses usually employ an external contractor for some tasks that they cannot undertake effectively themselves. These tasks may include specialist cleaning of extractor systems and drains, waste collection and disposal. Large catering, manufacturing and retail businesses often contract out all their cleaning requirements. The advantages of using an outside contractor for cleaning include:

• the contractor provides specialised expertise and trained cleaning staff to achieve a standard of cleaning that in-house staff may not be able to provide;
• a reputable cleaning service will be fully insured which will protect the food business and its equipment in the event of theft or damage;
• an external cleaning service removes the burden of cleaning from in-house staff, enabling them to concentrate on their core responsibilities like retail service, cooking and food production, therefore raising staff morale;
• a comprehensive efficient cleaning contract can reduce the food business’s operating costs;
• cleaning services may be provided when the food business is closed, say during the night. The food business’s activities will not be interrupted;
• the contractor provides specialised equipment as well as cleaning chemicals saving costs to the business;
• an effective cleaning contract reduces the risk of foodborne illness and provides a visual standard of cleanliness that creates a favourable impression to customers; and
• a well-run and fully documented cleaning contract may contribute to a due-diligence defence.

There are disadvantages of employing an external cleaning contractor, as opposed to keeping cleaning in-house:

• there may not be sufficient in-house management expertise to fully evaluate proposals for services and their costs;
• a poorly drawn up contract may fail to adequately cover key cleaning tasks and responsibilities on the part of management and the contractor;
• the food business’s management may not adequately supervise the services provided by the contractor resulting in unacceptable cleaning standards;
• external contractors may be selected on cost grounds alone. The cheapest contractor may cut corners using unsuitable or ineffective cleaning chemicals, or poorly trained staff. Insufficient time may be allocated to key cleaning tasks;
• contract staff shortages may result in poor cleaning standards or interruptions in waste collection, for example. Poor cleaning standards may result in a foodborne illness incident;
• there may be significant litigation costs in terminating an unsatisfactory cleaning contract, as well as costs arising from enforcement action taken because cleaning standards do not meet standards required under food safety legislation. A customer audit of the food business may identify an inadequate cleaning contract, or one that is poorly supervised by management; and
• the management of a food business have full control over in-house cleaning. Management understands the cleaning requirements of the business, and has the incentive to operate an effective cleaning schedule using well-trained employees. The external contractor may not have the same level of commitment to achieving and maintaining high standards of cleaning.

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