Evaluating two methods of testing residual sanitizer concentrations in food service establishments

Abstract

Objective: Utensils and tableware are food contact surfaces that have the potential to transmit disease-causing microorganisms if not washed, cleaned and sanitized correctly in a food service establishment. To prevent utensils and tableware from becoming vectors of disease, it is essential that operators and staff are able to adequately sanitize them and accurately test for it in a quick and convenient manner. It is also essential that Environmental Health officers are able to test whether adequate sanitization is occurring during their routine inspections. Currently there are no guidelines indicating the correct method of testing. Therefore, this study investigated two methods used to test residual sanitation concentration in a dishwasher. The purpose of this research was to determine if there is any difference in the two methods currently being used, and if so, which method is the more reliable one. Methods: LaMotte Chlorine Test Strips were used to detect the levels of chlorine in a commercial dishwasher. The chemically treated strips were dipped onto a freshly wet and washed utensil and directly in the rinse water of a dishwasher. Results: The difference in the mean of 60 samples from two independent groups was analyzed. Thirty samples were obtained from location one, the dishware l, and thirty samples were obtained from location two, the rinse water of the commercial dishwasher. The mean residual concentration was calculated and compared. The means demonstrated there is a significant difference (p = 0.035)between the two groups; the average residual concentration was lower for the dishware compared to the rinse water. Conclusion: Dishware is a vector capable of transmitting disease causing microorganisms if not sanitized adequately. Thus, it is important to ensure that dishes in a food service establishment have been thoroughly sanitized. The testing of that requires a consistent and reliable method. It is safe to assume that testing on the dishware is the best course of action to err on the side of caution.