Abstract: Scrubber sterilization method which initially sterilize a gas scrubber with an initial cleaning with hydrogen peroxide, provide an iodine level of approximately 5 to 10 mg/liter in water which is sprayed into the scrubber to contact the effluent gas stream and kill biological growth, provide injection of more concentrated iodine in water in the event the iodine level in the system falls below a predetermined level, and load the filtrate material in the gas scrubber with iodine to provide an unfavorable surface for adherence of biological growth as well as a secondary sterilization means in the event that the liquid stream with iodine is stopped due to equipment or power failure.