Application Note: Dissolved Ozone Measurements In Bottled Water

Bottled water is regulated at the federal and state levels and by industry to ensure that it meets all applicable safe water standards. The FDA regulates bottled water as a food product, and bottled water companies must comply with the FDA's Quality Standards , labeling regulations, and Good Manufacturing Practices (GMPs). On a global level, the Codex Alimentarius Commission, the food standards body of the World Health Organization (WHO), also guides bottled water standards. To some degree, the bottled water industry is also selfregulating. The International Bottled Water Association (IBWA) whose 1,200 members produce about 85% of the bottled water available on the market has developed regulations to complement federal and state standards.

Ozone (O3) is a preferred disinfectant for bottled water because it leaves no residual taste, color or odor. However, O3 is relatively expensive to produce and if it is not accurately controlled it has the possibility of creating some undesirable disinfection byproducts. For these reasons, it is essential for bottled water plants to monitor and control their ozonation process at precise levels.

Mineral waters that contain bromides will oxidize to bromate when exposed to excess levels of ozone. The FDA has limited bromate to less than 10 µg/L (ppb). To ensure proper disinfection and limit bromate formation, the International Bottled Water Association (IBWA) recommends that ozone be applied in the 1.0 to 2.0 milligram per liter (mg/L) range for a period of 4 to 10 minutes contact time. Application at this level helps maintain a 0.1 to 0.4 ppm residual ozone level at the time of bottling and provides an additional safety factor as the bottles can be disinfected and sanitized while being filled with product.

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