Standardising the testing of disinfectant wipes

There has been quite a bit of discussion lately about the suitability of laboratory testing methods for wipes. This is a crucial issue, and may explain to a large degree the differences in wipe performed when tested in parallel. For example, a study of wipes with sporicidal claims found that few actually demonstrated meaningful sporicidal activity!

A recent study in the Journal of Hospital Infection aims to standardise the testing of disinfectant wipes using an ASTM method. The protocol depends on using a “Wiperator”, which standardises the pressure and motion used to apply the wipe to the inoculated test surfaces. The new test protocol was put through its paces by three laboratories testing the efficacy of five disinfectant wipes against two common pathogens (S. aureus and A. baumannii). Reassuringly, all of the wipes tested achieved a >4-log reduction on the test bacteria within 10s of wiping, and 3/5 wipes tested achieved a >7-log reduction on the test bacteria. However, only one of the wipes tested (based on 0.5% accelerated H2O2) prevented the transfer of bacteria to another surface.

This methodology solves a number of common problems with other methods used to test the efficacy of disinfectant wipes, especially standardising the pressure and wiping motion; the inclusion of a measure of the risk of onward transfer of bacteria to other surfaces is another important inclusion in the protocol. It seems likely that this disinfectant wipe testing standard will quickly become the gold standard method.