Hepatitis A virus, poliovirus 1 and echovirus 1 were exposed to either 8 or 16 mg/Qt iodine under controlled extreme water conditions (5 degree C, 5 NTU Bentonite clay and 10 mg/L dissolved organic acids) at three pH values (4.5, 7.0 and 9.5). Virus titers were determined from halogen quenched samples collected at specific time points over a sixty minute contact time. The primary research objective was to determine if globaline (iodine) at present concentration (8 mg/tablet/quart of water) and used according to present instruction (1 tablet, 2 tablets if water cloudy or cold, and thirty minutes contact time) is sufficient protection against HAV or other enteroviruses. Iodine virucidal efficiency was dependent upon virus type, pH and iodine concentration. Iodine stability decreased above neutral pH. The three test viruses survived sixty minutes iodine contact at pH 4.5, 8 and 16 mg/Qt iodine and at pH 7.0, 8 mg/Qt iodine. At pH 7.0, 16 mg/Qt iodine, HAV was not detectable after one minute, echo 1 was not detectable after ten minutes, and polio 1 survived sixty minute contact. At pH 9.5, 8 mg/Qt iodine, showed the most rapid inactivation rate but viruses were detected at sixty minutes. At pH 9.5 and 16 ing/Qt, survival of HAV and polio increased. First order inactivation kinetics were not observed for the three test viruses under trial conditions.