A method of assessing the efficacy of hand sanitizers: Use of real soil encountered in the food service industry

In many outbreaks of foodborne illness, the food worker has been implicated as the source of the infection. To decrease the likelihood of cross-contamination, food workers must clean and disinfect their hands frequently. To ensure their effectiveness, hand disinfectants should be tested using rigorous conditions that mimic normal use. Currently, several different methods are used to assess the efficacy of hand disinfectants. However, most of these methods were designed with the health care worker in mind and do not model the specific contamination situations encountered by the food worker. To fill this void, we developed a model that uses soil from fresh meat and a means of quantifying bacteria that is encountered and transferred during food preparation activities. Results of studies using various doses of para-chloro-meta-xylenol and triclosan confirm that the method is reproducible and predictable in measuring the efficacy of sanitizers. Consistent, dose-dependent results were obtained with relatively few subjects. Other studies showed that washing hands with a mild soap and water for 20 s was more effective than applying a 70% alcohol hand sanitizer.