We are frequently advised to wash our hands before handling food. Why is practising good hand hygiene critical?
In this article, we explore various aspects of hand hygiene and its importance in food handling.
How do germs get onto our hands and the food we eat?
In the course of our daily activities, our hands inevitably come into contact with many surfaces where germs are present. Through these contacts, our hands become contaminated with germs, and act as vehicles to transfer germs to our food.
Some germs that can be found on our hands and can cause food poisoning include bacteria like S. aureus
and E. coli
. These bacteria can multiply rapidly when the food contaminated by the bacteria is left within the “temperature danger zone
” of 5o
C – 60o
C”, and cause food poisoning.
How does hand washing remove germs from our hands?
Proper hand washing can effectively remove many harmful bacteria and viruses such as E. coli, Salmonella, C. perfringens, S. aureus and norovirus. Proper hand washing involves two key aspects – the washing technique and drying.
The proper washing technique involves rubbing your hands together with soap and water for at least 30 seconds. Water by itself is ineffective in removing germs. Soap is needed to lift dirt, oil and germs off the skin, and the rubbing action helps to break up the dirt and germs.
The other aspect of handwashing is drying. Moisture enables the transfer of bacteria and therefore, it is important to dry hands thoroughly. The use of paper towels has been shown to be more effective than electric dryers for the drying of hands, as the rubbing action not only reduces the drying time, but also further removes residual germs. Reusable hand towels may be used but they should be changed frequently, especially when they become wet.
When should we wash our hands?
It is important to wash our hands before handling any food, especially food that is ready for consumption. In addition, we should always wash our hands after the following activities:
- Handling raw food
- Handling garbage and other waste material
- Using the toilet
- Touching money
- Cleaning surfaces
- Blowing nose or covering a cough or sneeze
The following 8 steps of hand washing are recommended:
- Wash palms
- In between fingers
- On the back of hands
- At the base of both thumbs
- On the back of fingers
- On fingernails
- On both wrists
- Rinse and wipe dry with paper towels
For more information on the 8 hand washing steps, please refer to MOH HealthHub - "Keep your Hands Clean"
Is hand washing necessary if gloves are used when handling food?
Gloves provide an additional barrier between bare hands and food. Therefore, the use of gloves helps to reduce the transfer of germs from hands to food, if they are used properly.
However, the use of gloves does not replace proper hand washing. Dirty hands will contaminate the gloves. Hence, proper washing of hands should be done before donning a fresh pair of gloves.
Gloves should also be changed frequently as they can become contaminated as easily as our hands and can similarly act as vehicles to transfer germs to food. Gloves can also be damaged easily, and small holes may form during usage. As such, it is important to change to a fresh pair of gloves frequently, particularly when switching between tasks (e.g. after handling raw food, money or garbage, or touching exposed skin, nose or eyes). Gloves used for food preparation should also not be used for other tasks.
Notwithstanding, there may be instances when the use of gloves may pose safety risks and/or are not practical. These include the preparation of machine-pressed sugarcane juice, clapping of roti prata and moulding of sushi:
(i) Handling of sugarcane for mechanical juicing
- Gloves may get trapped in the juicer machine and food handlers may not be able to extricate their hand in time, posing an occupational safety risk for food handlers.
- In addition, there is minimal duration for bacterial growth or toxin formation and the food safety risk is relatively low as sugarcane juice is generally chilled with ice and/or consumed instantly after juicing.
(ii) Clapping of roti prata
- Due to the hot and oily texture of prata, it is not practical for food handlers to don gloves.
- The momentary act of clapping of the prata immediately after cooking is unlikely to result in significant microbial contamination.
- In addition, prata is generally consumed when it is hot or in a relatively short period of time after it is cooked. Hence, there is minimal duration for bacterial growth or toxin formation and the food safety risk is relatively low.
- The prata should be clapped immediately after frying while the prata is hot, and done by the food handler preparing the prata as he/she would have washed his/her hands before preparing the food.
(iii) Moulding of sushi
- Most sushi restaurant chains use machines to shape the sushi rice. However, in cases where the sushi is moulded or rolled by hand, it is not practical for food handlers to don gloves while doing so due to the stickiness of sushi rice.
- After preparation, sushi is generally displayed in chillers. As such, there is minimal duration for bacterial growth or toxin formation and the food safety risk is relatively low. Food handlers are required to ensure that food is kept out of the “temperature danger zone”.
Hence, it is important for proper hand washing to be done before preparing any food. This applies to all types of food preparation, and regardless of whether gloves are used.