Abstract
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. Project submitted in partial fulfillment of the requirement for the degree of Bachelor of Technology in Environmental Health, British Columbia Institute of Technology, 2016.