Manual cleaning of machinery, equipment and surfaces is the most common method employed throughout the food manufacturing industry. Because manual cleaning is locally controlled by the operative, the risk of cross contamination can be significantly less than cleaning utilising physical energy input from medium or high pressure water. Other benefits include the relative low cost of the equipment required to carry out these tasks (buckets, brushes, cloths, scourers etc).
Manual cleaning can however be very labour intensive and also extend the length of time needed to carry out a cleaning task efficiently.
Manual cleaning will usually involve either a neutral detergent, a QAC based detergent or a light/medium duty alkaline detergent. A 1-2%v/v solution typically at 45ºC is used. These light duty detergents will not perform as well as the higher alkalinity products on protein or carbonised soils.
It must also be noted that although there can be a significant reduction in the generation of aerosols and overspray in comparison to medium / high pressure cleaning, cross contamination can occur in various other ways, such as using dirty cleaning tools.
Small Item Cleaning
Manual cleaning of small items is essentially carried out in the same manner as domestic dish washing and is used to clean small items including utensils, knives, small machine parts, blades, depositor parts etc. Usually the following method is used:
Remove all gross debris and place into waste container
Pre-rinse using clean low/mains pressure water
Soak in a warm, mild detergent solution (approx. 45(C) for a minimum 20 minutes. Care should be taken when soaking sensitive items such as rubber seals as the hot water may cause them to expand
Scrub with either a scouring pad or brush
Rinse with clean low/mains pressure water
Immerse in a disinfectant solution for a minimum 20 minutes or until next use or reassembly. Disinfectant may have to be rinsed off in some cases, such as during the manufacturing of organic products.
Leave to drain and store dry or alternatively leave immersed in disinfectant solution until use or reassembly.
For heavily soiled small items and parts that cannot be cleaned using a mild detergent it may be necessary to soak in a heavy duty alkaline/caustic based detergent solution (protein or carbonised soil) or an acid based detergent solution (mineral deposits).
Machinery & Environmental Cleaning
The manual cleaning of machinery, walls, floors, doors, drains etc can be very time consuming and will probably not achieve the results that can be achieved using a modern medium pressure wash-down system. However in certain manufacturing and packaging environments manual cleaning is the only option.
The following method is typically employed:
- Remove all gross debris by hand and place into waste container (this may be followed by rinsing off any further debris with low/mains pressure water).
- Scrub/wipe of surfaces using a brush/pad/cloth (floor brush for floors and drains) dipped in the detergent solution.
- Rinse off detergent residue and any remaining debris with clean, low/mains pressure water, buckets of water or wipe off with a clean cloth.
- Spray all food contact surfaces with a disinfectant solution using a trigger/pump-up sprayer or soak in disinfectant solution, leaving in contact for a minimum 20 minutes. Disinfectant may have to be rinsed off in some cases such as during the manufacturing of organic products.
Water fed brushes can be utilised to improve the efficiency of the clean. The brush head can also be fed with detergent solution.