Cleaning and sanitising in food businesses
Legislation requires food premises including fixtures, fittings and equipment to be kept clean. Utensils, equipment and surfaces that come in contact with food must also be sanitised. This may include equipment used to clean food contact surfaces, for example cleaning cloths.
- the difference between cleaning and sanitising
- steps to effectively clean and sanitise
- chemical types
- types of sanitisers
- tips for chemical sanitising
- importance of thoroughly cleaning and sanitising mechanical equipment
Cleaning is the process of using a detergent and water to remove residual food matter, visible dust, grease, dirt, stains and odours from all surfaces, fixtures, utensils and equipment.
Sanitising is the process of killing food poisoning bacteria (what you cannot see) and is achieved by using heat and/or chemicals. This process should reduce the number of microorganisms to a level that does not compromise the safety of food with which it may contact and does not permit the transmission of infectious disease.
- Pre-clean - remove dirt and food by sweeping, scraping, wiping or rinsing with water. Remember to disassemble equipment before if applicable.
- Wash - use warm water and detergent. Soak if necessary.
- Rinse - rinse off detergents and any remaining food or dirt.
- Sanitise - sanitise to eliminate/reduce microorganisms to safe levels.
- final rinse - rinse off sanitiser (if necessary).
- dry - air dry, use a single use towel or clean tea towel.
It is important to know the general categories of chemical types to ensure you are using the appropriate one.
Detergents are soap in liquid form. They attract and wash away grease, dirt and debris from surfaces. They do not kill bacteria.
Sanitisers are chemicals that are capable of destroying microorganisms including food poisoning and other disease-causing bacteria. When manufacturer’s instructions are followed, they can reduce surface contamination by bacteria to a safe level.
Disinfectants are commonly household cleaning products suitable for toilets and floors but not always for food contact surfaces. They generally contain deodorants. They must not be used as sanitisers for food contact surfaces (unless advised by the manufacturer that it is safe and suitable to do so).
Sanitising is not a substitute for cleaning and is most effective at killing food poisoning bacteria when performed after cleaning. The two most commonly used methods of sanitising are heat and chemicals, or a combination of both.
Hot water must reach a minimum of 77oC for at least 30 seconds to be effective. A heating element should be used to keep the water temperature at 77oC or higher. Water at this temperature can be dangerous, so this method is recommended for use with specialised equipment such as dishwashers or other processing equipment with cleaning-in-place technology.
It is important to note that there is a difference between how commercial dishwashers and domestic dishwashers work. In general, commercial dishwashers use high water temperatures (above 80oC) whilst domestic dishwashers use a lower temperature (around 65 to 68oC). Since domestic dishwashers operate at lower temperatures, it is important that the longest cycle time and hottest temperature setting should be used for effective sanitation to occur.
It is the businesses’ responsibility to ensure the dishwasher used is effectively sanitising. To demonstrate this, businesses may require technical specifications for the specific dishwasher model they are using. For further information, refer to Safe Food Australia, Appendix 4.
Tips for effectively sanitising with a dishwasher:
- know your machine – how does it work, what are the effective temperatures, what onsite variables affect operation, what monitoring do you need to do to ensure its effective operation
- ensure you are using the correct detergent/chemical type (if applicable)
- use the hottest rinse cycle available
- ensure staff are aware of correct operation and which rinse cycle to use
- check that equipment and utensils are clean when removing from the dishwasher
- clean the dishwasher to ensure no build-up of food residues
- maintain and service the dishwasher correctly.
Chemical sanitisers are also an effective way to sanitise. Some dishwashers are designed to also use chemicals to sanitise. Food businesses must ensure that any chemical sanitiser used is “food grade”, as specified by labelling and material safety data sheets, and that it is used and stored in a manner that will not contaminate food. Food grade indicates that it is safe for food contact surfaces. When using chemical sanitisers, it is important to always refer to the manufacturer’s instructions.
When sanitising manually, the following methods can be used:
- items that fit in a double bowl sink – wash in detergent and hot water in the first bowl and then sanitise using a chemical sanitiser and water (if applicable) in the second bowl (adhere to manufacturer’s recommended contact times).
- items that do not fit in a sink and all other food contact surfaces – thoroughly clean and then use a spray bottle to apply the sanitiser.
In both instances, allow sufficient time for the sanitiser to work and then allow to air dry or wipe off with a clean sponge, cloth or single-use paper towel.
Commercial sanitisers are available from a range of commercial chemical suppliers and retailers. The most commonly used sanitisers used in food businesses contain chlorine or quaternary ammonium compounds (QUATs) as active ingredients. These must be used in accordance with the manufacturer’s instructions. It is also important to check that the sanitiser you use is food grade along with any other information on its effectiveness in sanitising and ensuring it does not inadvertently contaminate food.
Bleach is an inexpensive chemical that can be used to sanitise. Only plain, unscented bleach should be used and generally range from 4% to 10% chlorine (the active ingredient) as indicated on the label. Diluted bleach solutions (see table below) should be made up every 24 hours as the chemical breaks down and becomes ineffective after this time. Contact time may vary between brands but 10 minutes is a good rule of thumb. Utensils, equipment and surfaces can be left to air dry (no rinsing required) unless stronger concentrations than recommended are used.
Concentration for sanitising with bleach
- Household bleach (4% chlorine) — 2.5mL in 1L water OR 25mL in 10L water
- Commercial bleach (10% chlorine) — 1.0mL in 1L water OR 10mL in 10L water
Other chemical sanitisers
Other chemical sanitisers include organic sanitisers and combined detergent-sanitiser chemicals. Sanitisers with peracetic acid, hydrogen peroxide or organic acids as active ingredients are examples of organic sanitiser and must be used in accordance with the manufacturer’s instructions. Specially designed detergent-sanitiser chemicals may be appropriate for some small businesses with limited sanitation requirements and a single bowl sink. These must be used in accordance with the manufacturer’s instructions and should be effective on lightly soiled surfaces with no protein or fat residues.
Other alternatives such as vinegar, lemon juice and methylated spirits should not be used as sanitisers. Vinegar and lemon juice are weak acids and not effective at sanitising. Methylated spirits can leave chemical residues on surfaces which may taint food rendering it unsuitable. Citrus based cleaners are not proven to have a sanitising effect and should only be used as cleaning agents.
- ensure your chemical sanitiser is food grade
- sanitisers are most effective at the correct dilution – check the manufacturer’s instructions
- prepare diluted chemical solutions as required to ensure it remains effective (for instance, daily if required)
- sanitisers need time to work – check the contact time required as they vary for each product
- check if the sanitiser needs to be rinsed off after it has been applied
- check the expiration dates of your chemicals to ensure the active ingredients are still effective
- chemicals must be clearly labelled (PDF 336KB), especially when they are transferred from their original packaging
- chemicals must be stored (PDF 336KB) away from food and food storage areas to minimise the risk of contamination
- ensure utensils, equipment and surfaces are dry after sanitising before reuse
- ensure your staff know how to correctly use your chemical sanitiser.
Sometimes, mechanical equipment can look clean on the outside but may be dirty on the inside. Mechanical action may draw food and bacteria into the inside areas of equipment where bacteria can grow, multiply and then contaminate the next food that is prepared with the equipment.
So it is important that all equipment can be dismantled enough for it to be thoroughly cleaned and sanitised.
See the Cleaning and sanitising – mechanical equipment fact sheet (PDF 115KB) for more information on how to effectively clean and sanitise mechanical equipment.