A recent survey of mains-fed water coolers in several premises (see earlier blog) has shown that microbial contamination of the inside of taps is considerable, even a short time after a sanitising service visit. This is particularly acute with high-use coolers in public areas such as schools and hospitals. In some cases the insides of the taps were colonised with the opportunist pathogen Pseudomonas aeruginosa. Whereas, healthy users would not necessarily be harmed, those with compromised immune systems may well be affected. This may be critical in certain hospital departments.
Although the recommendation to spray the insides of the taps regularly with a disinfectant spray, such as hydrogen peroxide, may well alleviate the problem temporarily, the re-contamination is likely to occur rapidly. An earlier blog describes the use of anti-microbial surface treatment to provide a longer-lasting disinfectant or bacteriostatic effect in several applications. Application of sprays which provide a long-lasting anti-microbial effect inside cooler taps is now possible. These sprays are taint-free and safe for use on water contact surfaces. However, further work is required to establish the efficiency in use of these sprays, for example, how long-lasting are they, does the applied spray need to dry out inside the tap, how much is flushed out when the tap is used again and how much could end up in the water to be drunk? We know more about peroxide sprays, which are also taint-free and harmless in the water (peroxide is sometimes used to purify water), so that more work needs to be done with the new anti-microbial sprays that have recently appeared on the market.