Evaluating the effectiveness of alcohol-based hand sanitizers compared to alcohol-free hand sanitizers

Description

Background and Purpose: Hand washing is one of the most important critical control points in public
premises in preventing the spread of bacteria and viruses. There is vast research on the effectiveness of
alcohol-based hand sanitizers in killing germs. However, the efficacy of alcohol-free hand sanitizers lacks
real-world evidence. With little to no guidelines in which one type of hand sanitizers may be more
appropriate depending on the types of public premise such as food establishments, hospitals, work place, or
schools, Environmental Health Officers(EHOs)/ Public Health Inspectors(PHIs) will need to educate the
public and operators on the effectiveness of these hand sanitizers and their advantages and disadvantages.
The purpose of the study was to compare the effectiveness of alcohol-based hand sanitizers and alcoholfree
hand sanitizers by conducting statistical analyses of the reduction in mean E.coli counts.
Methods: 60 pigskins were prepared (30 for alcohol-based hand sanitizers, 30 for alcohol-free hand
sanitizers), which were inoculated with E. coli, then applied either alcohol-based hand sanitizers or alcoholfree
hand sanitizers. After 48 hours of incubation for E.coli growth, E.coli was counted. The difference in
mean E.coli counts before applying hand sanitizers and after hand sanitizers was calculated, then compared
between the two hand sanitizers.
Results:
The mean E.coli reduction count (CFU) from alcohol-based hand sanitizers (30 samples) was 10.200; the
median was 11; the standard deviation was 1.7889; the range was 5.0000.
The mean E.coli reduction count (CFU) from alcohol-free hand sanitizers (30 samples) was 10.233; the
median was 10.5; the standard deviation was 0.8976; the range was 3.0000.
The statistical t-test resulted in p-value of 0.1034.
Conclusion: There was no significant difference between the two types of hand sanitizers. Both the
alcohol-based hand sanitizers and alcohol-free hand sanitizers effectively reduced the number of E.coli
counts (CFU) by averages of 10.2000 (92.7% reduction) and 10.2333 (93.03% reduction) respectively.
While the BC Centre for Disease Control recommends 60 percent alcohol hand sanitizers to prevent the
spread of germs, this research showed that alcohol-free hand sanitizers with sulfactants, allantoin, and
benzalkonium chloride (SAB) formula is just as effective in killing germs. Therefore, EHOs/PHIs can
educate the public and operators on the advantages and disadvantages on the two types of hand sanitizers in
preventing the spread germs during the flu season and give practical advice or guidance on which type of
hand sanitizers would be most appropriate in restaurants for example., Peer-reviewed article, Published., Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2016., Peer reviewed, Alcohol-based hand sanitizers, Benzalkonium chloride, E. coli, Alcohol-free hand sanitizers