Papaya (Carica papaya L.), belonging to the family Caricaceae, is rapidly becoming an important fruit internationally, both as fresh and processed products (Paull et al., 1997). The fruit is climacteric and susceptible to postharvest losses due to ethylene-induced ripening. Currently, there is a high level of interest in postharvest applications of ozone for decay control and as a potential sanitizer against human pathogens. Ozone has been affirmed ‘Generally Recognized As Safe’ (GRAS) status as a food processing aid and is compliant with the Environmental Protection Agency Disinfection by Products Rule (US-FDA, 1997).