The comparative study of ClO 2 disinfection was discussed in the previous section; the similarity of inactivation of PO1 and /X174 was apparently fortuitous, in that the porcine enterovirus, which resembled PO1 biologically, lost infectivity much more rapidly than PO1 and either bacteriophage (Olivieri et al. 1983) . We compared an FRNA coliphage (MS2) and a small DNA coliphage (/X174) with HAV under various conditions of inactivation: MS2 inactivation was fairly similar to that of HAV during heating in water and milk, especially at 72°C (Mariam and Cliver 2000b) . Both phages were more susceptible than HAV to drying and to ClO 2 disinfection. A UV disinfection study yielded decimal inactivation doses for FCV, HAV, PO1, MS2, and /X174 of 47.85, 36.50, 24.10, 23.04, and 15 .48 mW s/cm 2 , respectively .