Hand rubs containing alcohols such as isopropanol (IPA) or ethanol (EtOH) are widely
used for hygienic hand disinfection, and are presented in different formats (i.e.
liquid, gel or foam).
To determine if there is any difference in efficacy between these two active ingredients
in the three formats. In addition, an assessment of the drying time was undertaken.
Two non-commercial, ‘standard’ formulations were tested in each format: one containing
60% IPA, and the other containing 80% EtOH.
EN 1500 tests were performed with 20 volunteers to assess efficacy. The reference
product was 2 x 3 mL of 60% IPA for 60 s, as described in EN 1500 (2013). The test
products were 3 mL of liquid, gel or foam format; one full EN 1500 test was performed
for each formulation (60% IPA and 80% EtOH). To assess drying time, two different
volumes (1.5 and 3.0 mL) of the test formulations in liquid, gel or foam format were
applied to the hands of 15 volunteers. Volunteers self-reported when their hands were
dry; at the end of the test, the volunteers were asked to rate the time taken to dry
on a three-point scale (too short, OK, too long).
This study found no difference in antibacterial efficacy attributable to formulation
or format for the two ‘standard’ ABHR formulations, as assessed by EN 1500. When measured
objectively, the EtOH-based formulations dried more rapidly than the IPA-based formulations,
and for both formulations, gels took longer to dry than other formats. User perception
of drying time broadly agreed with objective measurement.
Given that there was no difference in efficacy and only moderate difference in drying
time, it is proposed that ABHR in liquid, foam or gel format may be appropriate, provided
that the specific product passes the required efficacy and safety standards.