Study: Sanitizer Formulation Impacts Efficacy, Guidance for Use in Food Settings Needed
A recent study from the Arkansas Center for Food Safety underscores the importance of application time and product formulation in the effectiveness of hand sanitizers—critical tools in preventing the spread of foodborne viruses.
The Arkansas Center for Food Safety is a part of the Arkansas Agricultural Experiment Station, which is the University of Arkansas (U of A) System Division of Agriculture's research arm. The study was conducted by Kristen Gibson, Ph.D., U of A Professor of Food Safety and Microbiology and Director of the Arkansas Center for Food Safety; alongside Francis Torko, Ph.D. student and Research Assistant in the Department of Food Science at U of A.
Using 30 volunteers, the study evaluated five commercially available foam hand sanitizers. Results showed that rubbing hands until the sanitizer dried led to significantly greater viral reduction compared to the standard 10-second rub. This finding is especially relevant in food environments where hand hygiene is essential to minimizing microbial contamination risks.
The study also tested both alcohol-based and benzalkonium chloride-based sanitizers against surrogate viruses representing those that cause gastrointestinal distress (i.e., norovirus) and respiratory symptoms (i.e., influenza, coronavirus). According to U.S. Centers for Disease Control and Prevention (CDC) estimates, norovirus is the top contributor to foodborne illness in the country, causing 5.5 million cases in 2019 alone. Additionally, most viral outbreaks (e.g., norovirus) are caused by contamination from ill food workers.
Notably, the research revealed that formulation, rather than just active ingredient concentration, plays a pivotal role in sanitizer efficacy. For example, a 63 percent isopropanol product showed a greater log reduction than a 70 percent isopropanol product due to differences in formulation.
This finding is in line with previous studies cited by Drs. Torko and Gibson, which demonstrated significant differences between products with similar active ingredient concentrations, as well as a lack of significant differences between products with varying active ingredient concentrations. For example, studies showed that reducing glycerol (a moisturizing ingredient that slows alcohol evaporation) in sanitizer formulations positively impacted efficacy.
The insights are valuable for high-contact settings like food establishments, where hands frequently interact with surfaces and food, increasing the risk of pathogen transmission.
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The study also emphasized the need for evidence-based practices to guide sanitizer use in real-world conditions, including proper volume and rubbing duration.
Supported by the U.S. Department of Agriculture’s National Institute of Food and Agriculture (USDA-NIFA), the research contributes to ongoing efforts to strengthen food safety protocols and reduce viral contamination risks in food handling environments.
