Abstract
The Kinetics of inactivation of poliovirus type 1 and bacteriphage f2 by aqueous chlorine were affected by the chlorine concentration, temperature, pH and ionic content. Chlorine had little effect above pH 9 or in the presence of ammonia. In most cases the kinetics were not compatible with exponential decay, probably due to heterogeneity in the virus preparations. Chlorine dioxide, bromine chloride, iodine and ultraviolet light were all found to be effective virucides for polioviruses and f2 and remained effective at pH 9 in the presence of ammonia. Loss of infectivity of poliovirus or f2 was not accompanied by any structural change observable by electron microscopy except in the case of iodine disinfection where poliovirus became permeable to negative stain and f2 did not adsorb in a specific manner. In doses much greater than those required for loss of infectivity all disinfectants produced structural changes in the virions.