Abstract: Milk or other beverages or foods may be preserved by adding thereto a minor amount of an aqueous germicidal solution of elemental iodine, hydrazine as hydrazine hydrate, and an organic carrier, such as polyvinyl pyrrolidone, with sufficient water to dissolve the other constituents. Such beverages include fruit juices and soft drinks. The germicidal solution may also be employed advantageously for purifying water to be used for drinking or swimming pool purposes, and also for purifying sewage effluent. The polyvinyl pyrrolidone largely overcomes the odor and taste of the iodine in the solution, while the hydrazine completely overcomes the iodine color. Nevertheless, the germicidal effectiveness of the solution is maintained. Sufficient hydrazine is employed to cause the iodine to be dissolved in the water and to remove the iodine color. A modified aqueous solution containing only elemental iodine and hydrazine as hydrazine hydrate may also be employed for the same purposes.