When it comes to the efficacy of surface sanitizers designed for inactivating the norovirus — a foodborne illness that causes diarrhea and vomiting — not all surface sanitizers are created equal, according to a new study.

Researchers from North Carolina (NC) State University are suggesting that total formulation — otherwise known as the active ingredients and non-active ingredients of sanitizers and disinfectants — impacts a surface sanitizer’s or disinfectant’s efficacy against norovirus.

To make this determination, the researchers applied human norovirus and Tulane Virus (a virus similar to human norovirus) to laminate material to demonstrate the efficacy of four commercially available food contact surface sanitizers with assorted active ingredients including ethanol, bleach, quaternary ammonium, and a lactic acid and surfactant blend. According to the team’s findings, the alcohol-based (ethanol) sanitizer reduced the amount of virus on the surfaces while the other products performed less effectively.

Further, the researchers performed a wiping test using paper towels. The laminate surfaces where paper towels were used to wipe the products were tested for the presence of residual virus. While the surfaces treated with the ethanol-based product were completely free from the virus, the paper towels used with the other three products contained high concentrations of the virus, and residual virus still remained on the surfaces after sanitizing.

“Surprisingly, there are few controlled scientific studies that have sought to evaluate the efficacy of commercial disinfectants in inactivating human norovirus on surfaces,” said Lee-Ann Jaykus, Ph.D., William Neal Reynolds professor of food microbiology at NC State. “The same can be said for studies that address the importance and value of wiping, which is a common step in the sanitization process. Our work confirms a long-suspected phenomenon that there are differences in the anti-noroviral activity of various commercial sanitizers, despite the fact that some are allowed to make label claims of such activity. Label claim applications are based on data collected using a different culturable surrogate than Tulane virus, one which is often more sensitive to inactivation than is human norovirus. Hence, users should take caution, even when using products making such label claims. As for wiping, this step results in removal of 99-99.9% (2-3 log) of virus but fails to reach the >99.99% (4 log) reduction standard required for a product to be considered efficacious. Importantly, it the sanitizing product does not inactivate norovirus, the towels used in wiping can harbor residual virus which poses a potential cross-contamination risk.”

The study, The Efficacy of Commercial Surface Sanitizers Against Norovirus on Formica Surfaces With and Without Inclusion of a Wiping Step, appears in the Journal of Applied and Environmental Microbiology.

To contact the author of this article, email mdonlon@globalspec.com