Date of Graduation
Master of Science in Food Science (MS)
Kristen E. Gibson
Philip G. Crandall
Second Committee Member
John A. Marcy
Handwashing (HW) is a long established method to prevent disease transmission. Ensuring effectiveness of current HW methods is essential for optimal HW and enhanced disease prevention. The objectives of this research were to 1) conduct a survey of soap type and volume in food service establishments in Washington County, Arkansas; 2) investigate how soap type impacts HW behavior; and 3) determine the difference in microbial reduction between foaming (F) and liquid (L) handsoap. For Objective 1, food service establishments in Washington County, AR were selected based on exclusion criteria and random number generations, and handsoap samples were collected to determine soap type and average volume. For Objective 2, 12 volunteers applied 1.0 g of Glo Germ™ (GG) to their hands and washed their hands, and then hands were swabbed in three locations to recover remaining GG. Swabs were eluted and absorbance was measured at OD370nm to quantify remaining GG using a standard curve. For Objective 3, hands of 24 volunteers were inoculated with approximately 108 CFU Escherichia coli C3000 or 108 PFU MS2 bacteriophage. Following completion of a standard HW protocol, microorganisms were recovered using a glove juice method, and culture assays were completed to determine microorganisms remaining. For the Washington County soap survey, the average volume of F and L handsoap was 0.64 ± 0.21 mL and 1.19 ± 0.46 mL, respectively. For Objective 2, no significant difference in behavior was determined in terms of GG remaining, HW time in the baseline HW and post GG HW, and baseline handrinsing time and post GG handrinse. Average time for the baseline handwash was (F) 11.17 ± 3.93 s and (L) 13.83 ± 7.30 s, and for the post GG handwash was (F) 13.33 ± 6.22 s and (L) 14.25 ± 7.70 s. For Objective 3, no significant difference in efficacy of F and L in overall removal of E. coli and MS2 combined occurred (p=0.56). However, F handsoap did remove significantly less MS2 when compared to E. coli (p=0.0008). This research indicates that use of foaming soap in food service may need to be reevaluated for control of foodborne viruses.
Conover, Danielle Marie, "Comparative Efficacy of Foaming and Non-foaming Handsoap in Reduction of Microorganisms in Handwashing" (2016). Theses and Dissertations. 1504.