Human noroviruses are a leading cause of foodborne illnesses, yet we still lack effective and rapid disinfectants. Carvacrol, a plant-derived phenolic compound, has demonstrated antiviral activity in previous studies. However, most evidence is based on long contact times and has not been evaluated using Tulane virus, a widely accepted human norovirus surrogate. This study investigated the antiviral efficacy of carvacrol, individual surfactants (CTAB and SDS), and carvacrol-surfactant emulsions using a 5-minute suspension assay designed to mimic realistic disinfection conditions. Viral reductions were quantified using plaque assays following neutralization with 3% meat extract. 

Across all treatments, antiviral activity against Tulane virus was minimal, with log₁₀ reductions ranging from -0.509 to 0.635. No formulation achieved a meaningful reduction. Negative log reductions were attributed to normal variability in plaque enumeration when true viral inactivation is negligible. The lack of efficacy observed is likely influenced by the short contact time, the inherent recalcitrance of non-enveloped viruses, and concentration limitations due to cytotoxicity. Overall, these findings indicate that carvacrol-based emulsions and the tested surfactants, at non-cytotoxic concentrations and short exposure times, likely lack ideal efficacy as surface disinfectants against Tulane virus. Future studies should investigate longer contact times, alternative formulation strategies that reduce cytotoxicity, and improved delivery systems to better assess the antiviral potential of carvacrol for food safety and public health applications.