Point-of-use filters: the next generation?

Tom Makin, BSC Hons, MWMSoc, chief consultant at ‘UK-wide, independent and impartial water quality specialist’, Envirocloud, discusses the ever-expanding range of point-of-use (POU) water filters now available to protect patients, staff, and visitors, against potentially harmful waterborne microorganisms, and reports on the positive results from a recent NHS hospital trial of a POU filter from a German manufacturer, which is reportedly ‘fully reprocessable’, and thus, following use, the filter cartridge and the housing can be decontaminated and re-used.

Point-of-use (POU) filtration is not a new weapon in the war against opportunistic waterborne pathogens. POU filters have been available in the UK for more than 15 years now, and have proven effective against a variety of microorganisms, such as Legionella, Pseudomonas, Stenotrophomonas, atypical Mycobacteria, Burkholderia, Giardia, Cryptosporidium, and many more. What is new, however, is that we now have a wide variety of POU filters available on the market, all of which are of slightly different construction and design, and vary in their efficacy. 

The concept behind POU filters is quite simple – create a physical barrier which attaches directly to the end of a tap or shower hose that has suitably sized pores which allow water to pass through, yet safely retain any planktonic bacteria and larger microorganisms such as protozoa. The reality, however, is much more complex. Assuming that the filter matrix is capable of physically removing all bacteria from the passing water, there are two main issues we commonly face. Firstly, the filter must attach perfectly to the chosen outlet. Any water leaking from between the filter, the filter adaptor, and the outlet, may allow potentially contaminated water to come into contact with vulnerable persons and result in infection.