Notes

Outline

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Characteristics of Chlorine Dioxide Effective on bacteria, fungi, virus Good effectiveness on biofilm penetration Very low impact of pH on efficacy Good stability in water (=HOCl; >O3) Low off-gassing in soluble form Less corrosive than chlorine No chlorinated Disinfection-By-Products Inactivated/decompose in sunlight

Methods of Production of ClO2 On-site generation; typically for large operations Can’t be shipped; > 10% is explosive!! Very toxic and strong irritant Engineer and restricted space controls required Stabilized (as Sodium Chlorite) Acid activation forms chlorine dioxide in batch Manual acid activation and proportion-pump feed Automated acid activation and in-line feed

Commercially Available Stabilized ClO2 Sanova Acidified Sodium Chlorate forms ClO2 on acid activation Biocide International Oxineâ Purogeneâ Sanogeneâ

Typical Reported Use Rates of ClO2 Produce mist (potable water only)                 5 ppm Produce wash (clean water rinse)            25-35 ppm Water disinfection (flumes)            25-50 ppm Biofilm removal (flumes and lines)            100 ppm Clean out (tanks, trays, bins)          100-200* ppm Storage room walls and floors         200-500 ppm* * Requires ClO2 protective mask

Some Reported Uses in FFV Potato storage : Controls Silver Scurf as fog/mist Carrot storage: Controls Botrytis, Sclerotinia, Thielaviopsis Carrot processing: Flume treatment for biofilm Banana and Mango: fungi control as fog Fresh-cut process water and equipment treatment Tomato: flume treatment for Geotrichum control

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