Inactivation of Hepatitis a Virus and MS2 by Ozone and Ozone-Hydrogen Peroxide in Buffered Water

The comparative inactivation of highly purified hepatitis A virus (HAV) and MS2 by 1 mg H₂O₂/L, 2.0 and 0.4 mg O₃/L, and 2.0 mg O₃/L plus 0.6, 1.0, or 1.6 mg H₂O₂/L, at 3-10°C, in 0.01 M phosphate buffer (pH 6-10) was determined. Both HAV and MS2 were completely inactivated (3.9-6 log₁₀) within 5 seconds in ozone solutions. Hydrogen peroxide did not inactivate MS2, but did inactivate 95% of the HAV. Both HAV and MS2 were completely (3.3-5.5 log) inactivated within 5 seconds in the oxidant mixtures at pH 6-8, but MS2 survival exceeded that of HAV at pH 10. MS2 was found to be a good model for predicting HAV inactivation by ozone and mixtures of ozone and hydrogen peroxide when both viruses are purified in the same manner.