“…the kitchen is probably the most important area in relation to the harbouring and transferring of infection” (Source 1)
Would you rather eat off your chopping board or off your toilet seat? Research findings would indicate the toilet seat to be the better option!
Check out the graph below: the kitchen is actually the room with the most bacteria in the home, including faecal coliforms, which are bacteria from human or animal waste. The kitchen sponge or dishcloth was the most contaminated site of all those tested, with over one million times the number of bacterial colonies found on the toilet seat. (Source 2)
Faecal coliforms are among the many pathogens that can cause food poisoning if they enter the human body. If your household includes young children, pregnant women, the elderly or the immunocompromised, they are likely to be particularly susceptible to food poisoning.
Approximately 5.4 million Australians get food poisoning each year, resulting in, on average:
Kitchen hygiene aims to prevent pathogens from entering, spreading around, and multiplying in the kitchen. These can occur in two key ways:
1. Cross-contamination - from food, people, pets and other household locations, or between kitchen locations e.g. via contaminated dishcloths and sponges which can act both as reservoirs and disseminators of pathogens
2. Inappropriate food handling, including storage and preparation
Cross-contamination can occur when you touch a contaminated site, such as the toilet flush, door handle, hand towel or kitchen sponge, and then touch food, a site which will come into contact with food, or a site on your body where the germs can gain entry to your system, e.g. your eyes or mouth. An estimated 80% of germs are spread by touch. (Source 4)
Therefore handwashing is the first key way to help prevent cross-contamination. Hands should be washed before preparing food and immediately after handling raw foods, especially poultry. There are many different hand hygiene products to suit different tastes and requirements. Click here to read more about hand hygiene.
Surface cleaning and disinfecting is also very important. Cleaning removes soils and grease which can encourage the growth of bacteria, and disinfecting reduces the numbers of pathogens to safe levels. Particular care is needed with benchtops and chopping boards before and after contact with raw foods as pathogens can survive on surfaces for considerable periods of time, especially when moisture is present. (Source 5) Floors need to be swept regularly and cupboards kept free from food spillage or leakage that could attract pests.
Surfaces can be cleaned with kitchen cleaners or general purpose cleaners. Some of these cleaning products include disinfectant agents, or specialised disinfectant products are also available. Disinfecting contaminated surfaces followed by paper towel wiping has been reported as the best hygiene practice for decontaminating surfaces which have contacted raw meat. (Source 6) Other specialised kitchen cleaning products include oven cleaners, stainless steel cleaners and drain cleaners.
Dishwashing of plates, cutlery, glasses, cookware and utensils removes food residue, grease and bacteria. Post-wash rinsing then removes dislodged food debris and detergent residue from the washed items. In fact, rinsing has been shown to be a vital step in decontamination, with unrinsed dishware actually increasing cross-contamination in the home. (Source 6)
Dishwashing by hand uses mechanical energy from scrubbing, thermal energy from hot water and chemical energy from a hand dishwashing detergent. Hand dishwashing detergents are liquid or gel formulations designed to remove baked-on food residues but to preserve the life of delicate crockery and be mild on hands. Pre-soaking greasy or lodged foodstuffs in hot water and dishwashing detergent can help the cleaning process. Hot water can also kill some microorganisms.
Automatic dishwashers use mechanical energy from water pressure and chemical energy from an automatic dishwasher detergent. Automatic dishwashing detergents are available as powders, liquids and tablets, and are specially formulated to be low-sudsing as foam would inhibit the effective scrubbing action of water. Rinse aids help reduce residues and streaks on washed items following rinsing.
Care needs to be taken with damp cleaning cloths and sponges – whether for surface cleaning or dishwashing - as they can encourage the rapid growth of microorganisms. Different cloths should be used for different jobs to prevent cross-contamination, e.g. a dishcloth used to wipe up raw meat juice should not also be used to dry hands. Cloths should also be cleaned and disinfected or replaced regularly.
The key to good food handling is temperature control. Food poisoning bacteria grow best from 6-60 °C, so food which has been left at these temperatures can cause food poisoning. Even if food is reheated and bacteria are killed, some produce toxins that are not destroyed by heat. Therefore, kitchen hygiene also includes suitable food storage and preparation to minimise the time food spends in this temperature ‘danger zone’.
“Doggy bags” from restaurants or takeaway outlets can present particular risks. If you take food home, it should be refrigerated as soon as possible and reheated so it is piping hot before consumption. Any uneaten “doggy bag” leftovers should be discarded after 24 hours. (Source 7)
The NSW Food Authority provides key food safety tips – “Keep it cold”, “Keep it clean”, “Keep it hot” and “Check the label” – at www.foodauthority.nsw.gov.au/consumers/keeping-food-safe/key-tips/. For more information call the NSW Food Authority helpline on 1300 552 406.
Finally, a hygienic kitchen is pest-free. Keeping food securely covered, removing food debris from floors and benches promptly, and disposing of rubbish in a securely covered bin will help. Click here for more information on pest control in the home.
Source 1: Scott, E., Bloomfield, S. F. and Barlow, C. G. 1984, “Evaluation of Disinfectants in the Domestic Environment under 'In Use' Conditions”, in The Journal of Hygiene, Vol. 92, No. 2. pp. 193-203
Source 2: Rusin, P., Orosz-Coughlin, P. and Gerba, C. 1998, “Reduction of faecal coliform, coliform and heterotrophic plate count bacteria in the household kitchen and bathroom by disinfection with hypochlorite cleaners”, in Journal of Applied Microbiology, Vol. 85, pp819-828
Source 3: NSW Food Authority www.foodauthority.nsw.gov.au/foodsafetyandyou/keeping-food-safe/key-tips
Source 5: Bloomfield, S. F. & Scott, E. 1997 “Cross-contamination and infection in the domestic environment and the role of chemical disinfectants”, in Journal of Applied Microbiology, Vol. 83, pp 1-9
Source 6: Kagan, L. J., Aiello, A. E. & Larson, E. 2002, “The role of the home environment in the transmission of infectious diseases”, in Journal of Community Health, Vol. 24, No. 4, pp 247-467
Source 7: Queensland Health 2015, Food safety information for doggy bags www.health.qld.gov.au/publications/portal/food-handling-business/doggy-bags.doc