FAQ, Frequently Asked Questions about Ozone.

QUESTION: What is Ozone?

ANSWER: Ozone is O3, or three oxygen atoms combined to form a single molecule of ozone O3. Oxygen is the most abundant element on earth and constitutes over 20% of the air in the earth's atmosphere. The oxygen atom is negatively charged and therefore unstable on it’s own, therefore is found as O2 and is most stable in the diatomic, O2 state. Ozone is the triatomic state of the oxygen element to create O3.

Ozone as an element is unstable and will revert back to oxygen naturally over time.


QUESTION: How is Ozone produced?

ANSWER: Ozone does occur in nature and is produced from electrical discharges such as lightning, and UV light. These same ozone production methods can be replicated and used commercially. A third method has also be developed where electrical discharges directly in water produce ozone. This is Electrolytic ozone generation.

Learn more about ozone production here:



QUESTION: Does ozone have an odor?

ANSWER: Ozone gas does have a distinct odor, while oxygen has no odor. Ozone has a fresh and typically pleasant odor at low concentrations. However, as the concentration of ozone increases it becomes irritating and has a sharp, pungent smell.

Ozone smells may be noticeable after a thunderstorm or near copy machines.

Note: as a person becomes acclimated to the odor of ozone, olfactory fatigue set’s in and the odor of ozone becomes less noticeable. If you are working in a an area that could have high ozone levels never trust your nose as a human safety device.


QUESTION: HOW long has ozone been used commercially?

ANSWER:  Ozone was first identified by a Dutch chemist, Van Marum in 1785. The name Ozone was first given to this molecule in 1840 by a German scientist, Friedrich Schonbien. It was at this time that interest in ozone was spurred with the first commercial ozone generator was developed in 1866. Ozone was initially used commercially in drinking water with the first full-scale plant-treating drinking water coming online in 1893 in the Netherlands. The first drinking water plant to come online in the USA was in 1903 in Niagara Falls, New York.

After this, the commercial use of ozone expanded rapidly to air treatment, wastewater applications, food processing, bottled water and others.

Learn more about the history of ozone here:



QUESTION: How long does Ozone last?

ANSWER: As soon as ozone (O3) is formed it begins to decay naturally back to oxygen (O2) due to the out-of-balance electron charge it possesses in the O3 form. The rate at which this natural reaction takes place is based on two primary factors.

  1. Temperature – higher temperatures increase natural reaction rates of O3 to O2 and therefore shorten the time that ozone exists in either air or water. Specific details on the time differences can be found at this link: https://www.oxidationtech.com/ozone/o3-half-life.html

  2. Oxidation Reactions – The primary goal of using ozone is the oxidation reaction that occurs. Ozone is an oxidant and will react with any compounds that can be oxidized. A greater number of oxidization compounds will cause O3 to react to O2 faster. A short list of common compounds ozone reacts with and the reaction kinetics can be found at this link: https://www.oxidationtech.com/ozone/ozone-reactions.html


QUESTION: Can Ozone be stored?

ANSWER: Ozone can be dissolved into water, that water can be quickly frozen into ozonated ice. In the frozen state ozone in water as ice can be stored for long periods of time, months and potentially years. There are limited practical uses for ozonated ice, and there are no other practical, or functional methods that we know of that can be used to store ozone in the O3 state.


QUESTION: Is Ozone harmful, and what, if any, are the long-term effects?

ANSWER: Ozone has been known for well over 100 years, therefore a great deal is known about it. Several regulatory agencies, including OSHA - Occupational safety and health agency - have stipulated that the safe allowable levels of ozone in air based upon the historical safety of ozone. These are outlined in detail here: https://www.oxidationtech.com/ozone/safety.html

Note: all ozone exposure limits are time-based. Higher ozone levels in air have a shorter allowable time-frame, and inversely longer time periods have much lower ozone limits.

The temporary affects of unsafe ozone levels would range from headaches to sore throats, irritation in the eyes, nose and the like, similar again to what we would experience in a traffic jam (where unsafe ozone levels are common).

Ozone dissolved in water is not considered unsafe and has no regulations on contact or usage. However, ozone dissolved in water can be off-gassed from the water and re-enter the air-space. In this condition, the above safety issues are applicable as ozone is in the air.


QUESTION: What are the applicable regulations regarding Ozone?

ANSWER: Ozone is regulated by OSHA and the EPA. OSHA regulates safe levels of ozone in the workplace. The EPA sets national ambient air quality standards (NAAQS) for ozone but has no industrial regulations in place. Learn more about ozone regulations at the link below:



QUESTION: How can you tell the level of Ozone?

ANSWER: Ozone can be measured in a variety of methods with single-use badges, handheld ozone monitors, and fixed-mount ozone safety devices. Each device has it’s unique nuances, features and accuracy. See link below for details on ambient and liquid ozone measurement devices:



QUESTION: How does Ozone work?

ANSWER: Ozone is an oxidant and does it’s work through the oxidation process. Oxidation is a chemical reaction in which electrons are LOST by atoms, ions or molecules. Reduction is the GAIN of electrons. Regardless of the name similarity, oxidation reactions need not actually involve oxygen atoms or molecules.

Oxidation, for non-chemists and those who have forgotten high school chemistry, is commonly just burning or rusting. If done instantaneously, it is an explosion. If done rapidly, it is burning. If done slowly, it is corrosion. When acting at a molecular level, it is just plain oxidation or part of the oxidation-reduction process. It can occur in gaseous or solid states as well as in liquids

While ozone is very powerful, it has a very short life cycle. When it is faced with odors, bacteria or viruses the extra atom of oxygen destroys them completely by oxidation. Any compound that can be oxidized can, and will be oxidized by ozone. A short list of common compounds ozone reacts with and the reaction kinetics can be found at this link: https://www.oxidationtech.com/ozone/ozone-reactions.html


QUESTION: Can ozone be dissolved into water?

ANSWER: Ozone is used in many water treatment and disinfection applications that require ozone to be dissolved into water. However, is ozone is generated as gas and therefore some action must take place to dissolve this gas into water, or any other liquid. Ozone is only partially soluble into water. The link below provides details and instructions on how to dissolve ozone into water:



QUESTION: How does ozone kill bacteria?

ANSWER: Ozone kills bacteria through a process called lysis, or cellular disruption. Lysis refers to an action that breaks down, or destroys the cell wall in order to release inter-cellular materials. Ozone oxidation will lyse (rupture) the cellular wall of the bacteria causing the internal materials to leak out of the cell. This action kills bacteria completely rather than merely ceasing the reproduction of the bacteria cells. This process is immediate, when ozone oxidizes the cell wall the bacteria is lysed and rendered inactive. However, it may take time for ozone to react with each bacteria cell and render positive results, or there may be other factors in real-world environments preventing the oxidation of bacteria by ozone.


QUESTION: Does ozone also kill viruses?

ANSWER: Ozone will deactivate virus by attacking the protein of the virus. Virus is a chemical entity and not living organisms. But it has DNAs that replicate fast. Ozone attacks this DNA and will render any virus inactive and unable to replicate. This process is immediate, when ozone oxidizes the protein of the DNA the virus is rendered inactive. However, it may take time for ozone to react with each active virus and render positive results, or there may be other factors in real-world environments preventing the oxidation of DNA protein by ozone.


QUESTION: Does ozone kill mold?

ANSWER: Ozone kills mold spores in air and water. Mold can only reproduce through mold spores there therefore, in the presence of ozone mold will not reproduce and will eventually die completely. This process may take time and is not immediate.


QUESTION: How does ozone eliminate odor?

ANSWER: Ozone is very effective at eliminating odor in industrial, commercial, and residential applications. The use of ozone for odor removal is popular throughout many industries. Most all odor is organic in nature and susceptible to oxidation. Ozone will oxidize carbon-based odors (smoke and some wastewater odors) to create CO, and CO2, while Ammonia (NH3) based odors will oxidize to NO and H2O. Hydrogen Sulfide (H2S) is oxidized to H2O and SO2. Ozone will eliminate odors in air and in water.


QUESTION: When ozone is used for odor removal can the odor return?

ANSWER: The odor that ozone oxidizes will not return. However, it is always possible that new odorous compounds are created, or released due to environmental changes.


QUESTION: What size ozone generator do I need?

ANSWER: The size of ozone generator will depend upon the application and your goals. We have ozone application experts on-staff and are willing to discuss your application and guide you to the proper solution. = https://www.oxidationtech.com/contact-us-101.html

If you have some info on your application and are looking to calculate ozone demand, see our ozone conversions and online calculators at link below:




QUESTION: How is ozone related to, or produced from Smog?

ANSWER: Ozone is formed at ground level by a chemical reaction between Nitrogen Dioxide (NO2) and/or Volatile Organic Compounds (VOC's) and UV rays from sunlight. The difference between this unhealthy ozone production and commercial ozone production, or natural ozone production in our ozone layer, is that ozone production from smog is an unhealthy cycle that is hard to break. In ozone production from smog the air quality is altered long term, ozone does not simply break down into harmless oxygen, but instead recombines to form NO2 in the atmosphere and re-start the unhealthy cycle again See link below for more details:



QUESTION: I have ozone values or units I do not understand, how do I convert to...?

ANSWER: We have a full list of commonly used, and peculiar ozone units of measure at the link below:



QUESTION: Ozone is corrosive, what materials should I use in my system?

ANSWER: Ozone is an oxidantTherefore is will oxidize materials just as oxygen will naturally oxidize materials in our world around us. Only ozone as a more powerful oxidizer will oxidize all materials faster.

When determining if a material can be used with ozone consider how that material holds to normal oxidation outdoors in fresh air. Or if using with water, how does material hold up to chlorine in city water. If the material breaks down over time, ozone will only speed that up by 100 times or more. For more details on ozone-resistant materials see link below:



QUESTION: What are some ozone applications, how is ozone used?

ANSWER: The largest use of ozone in the world is drinking water. Ozone is used as a disinfectant in water in large drinking water plants. The most commonly known use of ozone is odor control. Ozone is commonly used for odor elimination in disaster restoration. There are a wide variety of additional ozone applications, and more added every year. Additional ozone applications can be revised at link below:



QUESTION: How can I eliminate ozone?

ANSWER: Ozone naturally reverts back to oxygen over time. However, if high levels of ozone need to be eliminated and reduced quickly there are options. The following methods are commonly used:

  • Manganese Dioxide/copper oxide catalyst (Carulite)

    • Most commonly used. Effective for very high levels of ozone.

  • Carbon

    • O3 + C = CO2 or CO + O2. Very effective, however heat is generated in the process and this is a potential fire hazard.

  • Thermal oxidizer

    • Heat destroys ozone quickly

  • Aluminum oxides

    • Various forms can be used

  • UV light @ 254 nm wavelength

    • Can destroy ozone efficiently in water
    • Is not efficient in reducing ozone levels in air


QUESTION: Why isn’t ozone used more often? Are there any pitfalls?

ANSWER: Ozone is amazing and has many commercial uses. However, there are nuances to the use of ozone that make it challenging to implement properly. Below are a few of those issues to consider.

  • Ozone cannot be stored and must be produced by mechanical equipment on-site. Reliability issues with this equipment with minimal backup options can create challenges.

  • User success reports from other uses may be difficult to obtain. Many industries survive and operate under a veil of secrecy

  • Research is still ongoing for many ozone applications

  • Ozone is exciting and “easy to sell”, historically ozone has been oversold by overzealous salespeople without proper context on potential challenges.

  • Other impurities in air or water can create undesirable by-products in the oxidation process

  • All ozone systems must be designed with personnel safety in mind.