Comparing the effectiveness between gel and foam hand sanitizers

Abstract

Background: Hand sanitizers are commonly used as an alternative to washing hands with warm water and soap. There are a variety of different hand sanitizers including gel and foam and they are known to kill several bacteria. Many factors play a role in the effectiveness of hand sanitizers such as the alcohol concentration and the techniques used to apply hand sanitizers. Alcohol based hand sanitizers must have an alcohol concentration of 60 - 70% to be effective. There is currently no legislation regulating hand sanitizers and there is a lack of research focusing on differences between foam and gel hand sanitizers. This research study investigates effectiveness of gel compared to foam hand sanitizers by evaluating the prevalence of Escherichia coli (E.coli) on pigskins. Methods: To compare the hand sanitizers, microbiological sampling was completed. E.coli was introduced onto 65 pigskins. Five pigskins were used as a baseline to determine the average amount of Colony Forming Units (CFUs) of E.coli present prior to the application of hand sanitizers. One set of the 30 pigskins was applied with gel hand sanitizer, whereas the other 30 was applied with foam hand sanitizer. The pigskins were swabbed with QuickSnap swabs and plated onto 3M Petrifilms. The 65 petrifilms were incubated at 35oC for 48 hours. After incubation, the CFUs of E.coli present on the petrifilm were enumerated. The difference in CFUs was calculated to determine the reduction in E.coli and the overall effectiveness of hand sanitizers. Results: The data was analyzed by using the statistical software, NCSS. Statistical analysis showed that the findings were statistically significant and the null hypothesis (Ho: no difference in CFUs of E.coli between foam versus gel alcohol-based hand sanitizers) was rejected with a power of 0.9997 at p-value of 0.00000. This indicates that there is a difference in the ability to reduce E.coli between gel and foam hand sanitizers and gel sanitizers appeared to be more effective. Conclusion: These results indicate that there was a difference in the effectiveness between foam and gel hand sanitizers in reducing E.coli that was inoculated onto pigskins. However, consumers should be aware that hand sanitizers do not completely eliminate all pathogens. Though gel hand sanitizers are more effective, they should only be used when there are no other methods of keeping hands clean.