Ozone (\(O_3\)) is a molecule composed of three oxygen atoms. This extra atom makes ozone a powerful oxidant, a substance capable of readily taking electrons from other compounds. When this potent gas is dissolved into water, it creates ozonated water, which is utilized as a robust agent for disinfection and sanitization. Many people encounter this technology in modern dental offices or as a chemical-free method for cleaning and purification.
What Ozonated Water Is
Ozonated water is water that has been infused with ozone gas. The process of adding the gas to the liquid is known as ozonation, which results in a broad-spectrum disinfectant. This water is produced on-site because ozone is unstable and cannot be stored for long periods.
The two main methods used to generate the ozone gas involve electricity or light. One common technique is cold plasma corona discharge, where an electrical current is passed through dry oxygen or air, splitting the oxygen molecules (\(O_2\)) into single atoms. These single atoms quickly recombine with other \(O_2\) molecules to form the triatomic ozone molecule (\(O_3\)). Alternatively, ultraviolet (UV) light at 185 nanometers can be used to split the oxygen molecules. Once generated, the ozone gas is then bubbled into or mixed with the water using specialized equipment.
The Science of Ozone’s Action
Ozone is one of the strongest oxidizers permitted for use in water treatment, significantly more potent than common disinfectants like chlorine. Its disinfecting power comes from its third, loosely bonded oxygen atom, which is highly reactive. When ozonated water encounters a microbe, this reactive oxygen atom rapidly detaches.
The atom immediately attacks the cell wall of the pathogen, causing the cell to rupture and burst, known as lysis. This swift and destructive physical action inactivates the microorganism instantly. Unlike chemical disinfectants that must diffuse into a cell to interfere with its internal functions, ozone’s direct surface attack mechanism prevents microbes from developing resistance. This oxidative burst is effective against all known types of bacteria and viruses, damaging essential components like proteins and nucleic acids.
Practical Applications and Uses
The residue-free disinfection provided by ozonated water has led to its adoption across various sectors. In municipal water treatment, it is used to purify drinking water, often replacing chlorine to inactivate tough pathogens like Cryptosporidium and to remove substances that cause bad taste and odor. This application leverages ozone’s ability to break down complex organic compounds.
The food industry also relies on ozonated water for sanitization, particularly in washing produce and meat. It is applied to surfaces and equipment to control microbial contamination and has been recognized as Generally Recognized As Safe (GRAS) by the U.S. Food and Drug Administration (FDA) for food contact applications. In medicine and dentistry, the antimicrobial properties are used for sterilizing instruments and disinfecting wounds.
For dental applications, ozonated water is used to fight periodontal disease, control caries, and accelerate wound healing in the oral cavity. At home, smaller generators produce ozonated water for cleaning surfaces, sanitizing laundry, and as an antimicrobial rinse for fresh foods.
Stability and Safety Considerations
Ozonated water is highly unstable, which contributes to its safety profile. Ozone has a very short half-life, meaning it rapidly breaks down and reverts back to its stable form, oxygen (\(O_2\)). In tap water, its half-life can be just minutes, though in ultrapure, cold water, it can be extended to a few hours.
This rapid decomposition ensures that ozonated water leaves behind no toxic chemical residue on surfaces or in treated products. While ozone gas is toxic if inhaled, ozonated water is safe for contact and consumption when produced and used correctly. The instability of the molecule means that any residual disinfecting power quickly dissipates, reverting to harmless oxygen.