Abstract: A method for production and storage of hypochlorous acid is disclosed. The method comprises using high purity water achieved by a combination of softening and reverse osmosis steps. The shelf life is further improved by storing the hypochlorous acid in opaque PET bottles or Nylon/PE bags or nylon bags in a box. Solutions stored in opaque PET bottles exhibit the best stability. Anticipated uses of the extended life hypochlorous acid solution include sanitizer for food contact and non-food contact surfaces, a streak-free cleaner for smooth surfaces and a cut flower life extender. Other biocide uses include water treatment in oil and gas production, cooling tower, lazy river and swimming pools, process water distribution systems, drinking water, portable humidifier, fish tanks and treatment of metalworking fluids and lubricants.