Is it okay to drink ozonated water?

For over a century, ozone technology has been used to sanitize municipal water supplies and bottled water, making ozonated water a common yet misunderstood topic. This process is highly effective at destroying microbes, but many people are unsure about the safety of drinking ozonated water directly from a generator or for therapeutic purposes.

Quick Summary

This article explores the safety of drinking ozonated water, distinguishing between professionally treated municipal water and water from home generators. It covers the ozonation process, its proven disinfection benefits, and potential risks, including the formation of harmful byproducts if the source water contains certain minerals. We examine the unsubstantiated health claims versus the established applications, providing a comprehensive overview for safe consumption.

Key Points

• Ozonated Water is Used to Purify: Municipalities and bottlers use ozonation as a highly effective, chemical-free method to kill microorganisms and purify drinking water.

• Residual Ozone is Harmless: After disinfection, any residual ozone dissipates quickly, leaving no taste, odor, or chemical residue behind; it simply reverts to oxygen.

• Home Ozonation Requires Caution: Home-grade generators are unregulated, and improper use risks inhaling toxic ozone gas or generating dangerous byproducts.

• Beware of Bromate Risk: If your water contains bromide, home ozonation can create carcinogenic bromates; testing your water source is essential before attempting home ozonation for drinking.

• Health Claims are Largely Unproven: Many claims about therapeutic benefits are anecdotal or based on outdated research; robust scientific evidence for ingestion-based health improvements is lacking.

• Distinguish Treatment from Therapy: Professionally treated municipal or bottled ozonated water is safe. Unregulated ozone therapy devices are considered dangerous by regulatory agencies like the FDA.

• Wait Before You Drink: When using a home generator, allow the treated water to sit for at least 30 minutes to ensure all residual ozone has converted back to oxygen.

Understanding the Ozonation Process

Ozonation is a powerful water treatment method that uses ozone, a gas consisting of three oxygen atoms ($O_3$), to disinfect and purify water. When dissolved in water, this unstable gas reacts with contaminants through oxidation, destroying bacteria, viruses, and other microorganisms. Unlike chlorination, ozonation does not leave behind a chemical taste or residue, as the residual ozone quickly breaks down into harmless oxygen ($O_2$).

There are several methods for creating ozonated water, primarily through ozone generators which use either corona discharge or ultraviolet (UV) light to energize oxygen molecules. The resulting ozone gas is then injected into the water. For municipal water treatment, this process is meticulously controlled and followed by post-filtration to remove any particulate matter created during the process, ensuring the water is completely safe for consumption.

Industrial vs. Home Ozonation

While municipal treatment plants and commercial bottlers have used ozonation for decades with strict safety protocols, the rise of consumer-grade ozone generators for home use introduces new considerations.

• Municipal and Bottled Water: The water is treated, and by the time it reaches your tap or is bottled, any residual ozone has dissipated into oxygen. This is why the FDA has deemed ozonated water safe for this purpose.
• Home-Generated Water: When creating ozonated water at home, it is crucial to follow the manufacturer's instructions carefully. The water should be allowed to sit for a period (often 30 minutes) to allow any remaining ozone gas to dissipate before drinking, as inhaling ozone can cause respiratory irritation. The concentration and purity of the treated water are also less controlled than in professional settings.

Potential Health Benefits and Risks

Proponents of drinking ozonated water often cite various health benefits, from improving oxygen levels in the body to fighting disease. However, robust scientific evidence, particularly from recent, large-scale human studies, is largely lacking for many of these claims. Most established benefits of ozonation relate to its antimicrobial properties for sanitization rather than direct health boosts from ingestion.

Potential Benefits (Limited Evidence)

• Antimicrobial Effects: Ozonated water has proven effective in killing harmful bacteria and promoting healing, particularly in dental applications like wound irrigation and treating tooth decay-causing bacteria.
• Antioxidant Response: Some studies suggest that low-level ozone exposure can trigger a protective antioxidant response in the body, but this research is often based on animal models or outdated studies.
• Dental Health: Many dentists use ozonated water to disinfect the mouth and treat certain oral conditions.

Significant Risks and Considerations

• Bromate Byproducts: If the source water contains bromide ions, the ozonation process can produce bromate, a potential carcinogen. This risk is typically managed in municipal treatment but is a serious concern for home users who may not know their water's mineral content. For this reason, many industrial facilities control pH to minimize the formation of bromates.
• Inhaling Ozone Gas: Ozone gas is a toxic respiratory irritant. Mishandling home ozone generators or drinking water with a high residual ozone concentration can cause coughing, chest tightness, and lung damage.
• Lack of Regulation: The therapeutic use of ozonated water is not approved or regulated by agencies like the FDA, highlighting the need for caution.
• Corrosion: Because ozone is a powerful oxidant, concentrated solutions can corrode certain materials, including pipes and fixtures not made from resistant materials like stainless steel.

Ozonation vs. Chlorination

Comparing ozonation and chlorination for water treatment reveals key differences in effectiveness, byproducts, and application.

| Feature | Ozonation | Chlorination | Effect on Taste & Odor | Leaves no residual taste or odor; can improve water's natural taste. | Can leave a distinct chemical taste and odor. | Disinfection Speed | Acts very quickly, in seconds, against a wide range of microorganisms. | Requires longer contact time to be effective. | Chemical Residue & Byproducts | Leaves no chemical residue, reverting to harmless oxygen ($O_2$). Can create bromates if bromide is present. | Leaves a residual disinfectant that can form potentially harmful disinfection byproducts (DBPs) like trihalomethanes (THMs). | Effectiveness | Highly effective against a wide range of pathogens, including giardia and cryptosporidium. | Some parasites, like giardia and cryptosporidium, are resistant to chlorine. | Initial Cost | Higher initial equipment cost. | Lower initial equipment cost. | Residual Disinfection | No residual disinfection in water distribution systems once it reverts to oxygen. | A residual disinfectant remains in the system, preventing microbial regrowth. |

How to Approach Ozonated Water Safely

If considering home ozonation or any therapeutic use, it is crucial to proceed with caution and prioritize safety.

Best Practices

1. Use Reliable Equipment: Invest in a high-quality ozone generator with proper safety features and follow all instructions meticulously.
2. Ensure Safe Air Handling: Always use a generator in a well-ventilated area to prevent inhaling toxic ozone gas.
3. Allow Dissipation Time: After generating ozonated water, wait at least 30 minutes before drinking to allow the residual ozone to return to oxygen.
4. Know Your Source Water: Test your tap water for bromide levels. If bromide is present, the risk of carcinogenic bromate formation makes home ozonation inadvisable for drinking.
5. Consult a Professional: For therapeutic applications or specific health concerns, consult a doctor or a qualified water treatment specialist before beginning any regimen.

A Word of Caution

The FDA explicitly states that ozone therapy devices used outside professional medical settings are dangerous and potentially toxic, cautioning consumers against their use. While the FDA has approved ozonated water as a food-safe antimicrobial agent for food contact, this is a different application from ingesting therapeutic concentrations.

Conclusion

For drinking water, the ozonation process as used by municipal water suppliers and commercial bottlers is highly safe and effective, leaving behind no harmful residues. The potential issues arise with the unregulated use of home ozone generators, where the risks of inhaling toxic ozone gas and forming dangerous bromate byproducts can outweigh the unproven therapeutic benefits. It is critical to differentiate between professionally treated, safe drinking water and potentially risky home-generated water or unproven ozone therapies. While ozonated water is a powerful tool for disinfection, caution, proper procedure, and professional consultation are essential for safe use.

Frequently Asked Questions

Is drinking ozonated water dangerous?

Professionally treated municipal or bottled water is safe because the unstable ozone has already dissipated into oxygen before consumption. However, drinking water from a home generator immediately after treatment can be dangerous due to inhaling toxic ozone gas or forming carcinogenic bromates if the source water contains bromide.

How is ozonated water made?

Ozonated water is made by infusing water with ozone ($O_3$) gas, typically produced by an ozone generator using electrical discharge or UV light. This process is controlled in industrial settings to ensure safety and effectiveness.

Does ozonated water have any real health benefits?

While some proponents claim therapeutic benefits like increased oxygenation, most of these health claims lack substantial, recent scientific evidence. The primary established benefit of ozonation is its powerful disinfection ability, not its direct health effects when ingested.

Why is ozone gas dangerous but ozonated water can be safe?

Ozone gas is a toxic respiratory irritant and should not be inhaled. However, when used to treat water, the ozone quickly breaks down into harmless oxygen, leaving behind purified water with no ozone residue, making it safe to drink.

Can I use a home ozone generator to make safe drinking water?

Using a home ozone generator for drinking water carries risks, primarily the inhalation of ozone gas and the potential for carcinogenic bromate formation if your water contains bromide. It is safer and more reliable to use ozonated water that has been professionally treated and bottled or supplied by a municipal water plant.

What is the difference between ozonated and oxygenated water?

Ozonated water uses ozone ($O_3$) for purification, which eventually breaks down into standard oxygen ($O_2$). Oxygenated water contains extra dissolved oxygen molecules ($O_2$) from the start, a different product altogether.

Do ozone water systems leave a taste or smell?

No, one of the key advantages of ozonation is that it removes contaminants that cause unpleasant tastes and odors, and the ozone itself dissipates, leaving the water tasting fresh and clean.