BACKGROUND: Low concentrations of hypochlorous acid (HOCl) have been shown to exhibit both antibacterial and anti-influenza virus activity, but HOCl still has not been used to kill human rhinovirus (HRV). To model the antiviral effect of nasal irrigation with low-level HOCl in patients with the common cold, we tested the effects of a low concentration of HOCl on HRV infection of primary human nasal epithelial cells (HNEC). METHODS: Cells were infected with HRV for 24 hours and treated with HOCl three times, for 5 minutes each time, at 12 hour intervals. The effects of HOCl on rhinovirus-induced secretion of IL-6 and IL-8 were assessed by ELISA and HRV replication was determined by viral titration. RESULTS: HOCl treatment significantly inhibited HRV-induced secretion of IL-6 and IL-8 and significantly reduced viral titer. The effects of HOCl peaked at 1 minute after HOCl generation and decreased thereafter. CONCLUSION: These in vitro findings indicate that nasal irrigation with low-level HOCl solution may improve clinical symptoms in patients with the common cold.