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STUDIES OF THE HYGIENE OF KITCHEN CLOTHS & TOWELS
Keith Redway & Brian Knights

SUMMER 1998

The steady increase in the incidence of food poisoning cases in the UK and the 1996 E. coli outbreak have increased interest in all aspects of food hygiene and have helped to further demonstrate its importance in wholesale, retail, catering and domestic situations. The summer months see an increase in food poisoning cases caused by various bacteria such as Salmonella and Campylobacter species and, although the reasons for this are various, one of the main ones is the higher temperature (even with a British summer!). Higher temperatures will encourage bacteria to breed more rapidly and increase the risk of food poisoning occurring.

Various studies carried out at the University of Westminster have consistently shown that reusable kitchen cloths (e.g. dishcloths, non-woven cloths and sponge cloths) rapidly become colonized with various types of bacteria and the number of these is likely to be greater during the summer. After only one day's use in a domestic kitchen, the average reusable cloth contains over one billion bacteria! This is not that surprising because many bacteria can divide every 20 minutes under favourable conditions and reusable cloths in a kitchen provide everything that they need for rapid growth, i.e.


GROWTH OF BACTERIA

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To see larger version of graph, click on it and then use BACK button on your browser to return to this page.

The graph shows that if you use a reusable kitchen cloth at breakfast and leave just one bacterium in it, by mid-afternoon there could be over 1 million present and over 1 billion by the time of the 6 o'clock News.

However, it is more likely that not one but thousands of bacteria will be left in the cloth after breakfast and so the problem is actually worse than this graph suggests. Of course, bacteria do not usually continue to divide regularly every 20 minutes because they eventually run out of food and space but on average 1 billion is reached in a reusable kitchen cloth in less than 24 hours.


What can be done?

  1. Disinfect reusable cloths (e.g. using bleach) or wash them at a temperature of at least 70oC regularly.
    However, because the number of bacteria usually builds up to over 1 billion in less than 24 hours, this precaution, although recommended, is unlikely to prevent this increase unless it is carried out at intervals that are impractical in the average kitchen. It does help to keep numbers down, though, as does drying the cloth regularly. Unfortunately, bacteria soon re-establish themselves in any type of reusable kitchen cloth.

  2. Change cloths regularly.
    Again, although this is an obvious measure to take, most people would not want to change their cloth every day, or more than once a day, because of the expense.

  3. Use cloths impregnated with disinfectant.
    Studies have shown that these work quite well for a few days but then the effect of the disinfectant wears off and the cloths becomes colonized with as many bacteria as ordinary cloths. The newer types of cloth where an anti-bacterial agent is incorporated into the material work better for longer but the numbers of bacteria, although significantly less than those found in an ordinary cloth or sponge, are still considerable. Also, they are more expensive than ordinary cloths and sponges. Additionally, recent studies show that bacteria can become resistant to the anti-bacterial agent.


  4. Use anti-bacterial sprays and washing-up liquids.
    These can have a beneficial effect on the numbers of bacteria but are unlikely to inhibit them completely in a reusable cloth. Also, they are expensive and no substitute for good hygiene practices. As previously mentioned, bacterial resistance may be a problem.

  5. Use single-use cloths and towels.
    Single-use wipers are recommended for catering establishments and they would also improve hygiene in a domestic kitchen. Kitchen paper towels are the most obvious solution  to wiping up in the kitchen because they are:

  6. * single-use (do not transfer bacteria from one object to another)
    * dry (do not encourage the survival and growth of bacteria)
    * disposable (any bacteria are removed to the waste bin rather than being transferred to hands or food)
    * unlikely to encourage bacterial resistance (they do not contain unnecessary anti-bacterial agents)

    The use of kitchen paper towels is recommended for all appropriate wiping tasks in the kitchen.

Click here for more information on the University of
Westminster studies on kitchen cloths and towels