Cleaning with Liquid Ozone: What you need to know

We connect with a lot of parents and clients who are doing great work eliminating toxic chemicals from their homes.  They want to do even more, but they don’t know how – and that’s why they’re working with us.  We advocate and implement ozone technology as a Toxic-Free Cleaning option.
The cornerstone of this system is using liquid (or aqueous) ozone to replace chemical disinfectants.  Disinfectants are #1 on our list of 10 Most Toxic, so that’s a great place to start!  Aqueous, or liquid ozone is perhaps the most misunderstood and maligned technology that we utilize, largely because of misunderstandings about ozone in general.  Therefore, it has become the subject of undue concern.

To set the record straight, we’ve compiled a list of FAQs that we’ve received and answered for clients.

1.  How safe is liquid ozone?
Liquid ozone is in fact a strong oxidizer.  However, this does not mean that it is corrosive or combustible in the aqueous form (i.e. a solution of water).  In residential and commercial cleaning applications it is completely safe and won’t harm bare skin.  In fact, it may help to kill germs that your hands may have contacted during the cleaning process.  Therefore, you don’t need to wear personal protective equipment like gloves as you would with harsh, chemical-based cleaning solutions.

The concern with liquid ozone tends to be around it off-gassing and becoming gaseous which dissolved at proper levels and sprayed at safe presures won’t do (see #5 below).  That being said, nobody has ever died of liquid ozone exposure, whereas every day someone dies from household chemical exposure.  In fact, cleaning staff with asthma using our product say their breathing is perfect after working with it for 8 hours, contrary to the effect chemicals had on their breathing by the end of a shift.


2.  Is liquid ozone bad for asthma suffers?

No.  There is much confusion between liquid ozone and atmospheric ozone.  However, high-atmospheric (gaseous) ozone concentrations are bad for asthma and allergy suffers.  It can contribute to those Code Red days which the weatherman warns us about.  Atmospheric ozone is created by Mother Nature to try to break down air pollutants like NOX, VOCs, dust and allergens.  So on those Code Red days, more ozone is being produced naturally because there are more VOCs in the air.  Ozone gas is an indicator that there are other atmospheric contaminants that also affect asthma and allergy sufferers like VOCs, nitrogen oxides, dust and pollen.  Being quicker and easier to measure than the thousands of air pollutants, ozone gets a bad rap.

ozone production from smog

Man-made atmospheric ozone an also be produced by air purifying generators and filters to deodorize and disinfect rooms like operating rooms, hotel rooms, and even weather-damaged homes.  Allergy and asthma sufferers should indeed be wary of such high concentration applications.

Liquid ozone cleaners,  are different than atmospheric ozone generators. They create ozone gas infused into a watermedia, as opposed to the air.  Since ozone is an unstable molecule, it reverts to oxygen faster than the water evaporates without off-gassing.  In this way liquid ozone is a safe and preferential alternative to chemical disinfectants, many of which are themselves asthma triggers.
3.  How does liquid ozone work?
Ozone is a molecule of three oxygen atoms (O3) that is not stable and will breakdown quickly and form radicals that have a high oxidation potential, or redox.  This is what makes it a strong oxidizer and disinfectant.  During the oxidation, only one oxygen atom is used for the chemical reaction forming with hydrogen into OH-radicals.  Harmless to people, the ozone quickly attacks and eliminates contaminants it comes in which it contacts.  The oxidization reacts with the cell walls of bacteria and viruses the same way hydrogen peroxide and iodine do, causing cell poration of the microbe, which leads to its death.  The oxidation also removes electrons of molecules, eventually rendering them inert.  In this way O3 kills the bacteria that cause odors, viruses that cause illness, as well as breaks down bio matter on surfaces that provide the food for microbes.

4.  How much ozone do liquid ozone cleaning solutions contain?

It varies from application and manufacturer.  It can be is as high as 5ppm or more for high-volume industrial settings but is normally around 2-3 ppm for most cleaning and sanitation applications.  We keep ozone levels in water to reasonable levels to prevent off-gassing as ozone in air is regulated by OSHA.  
5.  How long does ozone last?
Ozone in aqueous form has a roughly 15 minute half-life (dependent upon temperature and water quality).  While is is obviously NOT radioactive as “half-life” may seem to imply, it is used because of ozone’s rapid degradation.  In 15 minutes half its solution has lost potency, at which point it is a better cleaning solution than disinfectant for the next few hours.
6.  What residues will liquid ozone leave after it dries?
Contrary to chlorine, which always leaves an oxidation or disinfection byproduct, ozone simply will revert back to oxygen.
7.  How strong is liquid ozone?
Ois is often compared to bleach and other chlorinated products as they are used in many of the same disinfection applications.  When used as such ozone has proven to be 50% stronger and 3000x faster than bleach.

In regulated cleaning applications, EPA guidelines direct us toward disinfection with chlorine and ozone.  For example, disinfecting with 1 ppm chlorine at a water temperature of 59°F and a pH of 7 requires a dwell time of 75 minutes. The disinfection efficiency achieved will be 99.9 percent.  Assuming the same temperature and pH, a concentration of 1 mg/l of liquid ozone water achieves a disinfection efficiency of 99.9% in only 57 seconds.  For this example giardia is the parasite used in the water sample because it is one of the most difficult microorganisms to kill.

8.  How is liquid ozone produced?

Ozone in water can be produced with an electrolytic ozone generating cell, or via corona discharge and dissolved into water via an ozone injection system.  Smaller systems or systems with ulltra-pure water can use an electrolytic cell.  All larger and industrial systems will use a corona discharge ozone generator and injection system.

9.  What other applications does ozone have?

Ozone has many applications on the home and commercially.  We covered cleaning using liquid ozone quite thoroughly by now.  Ozone generators can be made for water treatment plants and are in use all over the world.  There are applications for it in laundry and dish washing, but mostly in commercial or industrial settings.

Ozone generators have been used on both public and private pools as a means of disinfecting pool water.  Similarly, some aquariums use it to keep water fresh and germ-free.  Another important application is air purification.  As an oxidizer it attacks the bacteria at the cell level, killing them and their aerobic activity, which is what causes odors and areas of potential for infection.

SB-100 Ozone Spray Bottle

SB100 Ozone Spray Bottle
SB100 Ozone Spray bottle

The SB100 Ozone Spray bottle uses an electrolytic ozone generating cell to produce ozone in water as the bottle is used. No chance of low ozone levels as ozone is produced real-time while used. Great for small scale cleaning applications

Ozone Injection Systems

OST-40 ozone water system with optional dissolved ozone monitor and ORP monitor.
Ozone Injection System
Mobile ozone water system
Mobile ozone water system


For larger scale applications an ozone water system can be used. Ozone levels in water of 3-5 ppm can be created easily at water flow-rates from 3 – 300 GPM.

Should you have questions about cleaning and disinfecting with liquid ozone, please call our office.

59 thoughts on “Cleaning with Liquid Ozone: What you need to know

  1. Hello
    Ram here from Alberta, Canada.
    I wanted to start a disinfecting company here and wondered if i could produce ozonated water and spray it with an electrostatic sprayer as a disinfectant. do you think i can do this with this machine?

    there is a solution called vital oxide that can be used and i think they use this method or some sort.
    please let me know what you think. thank you

    1. You should check with your distributor for Vital Oxide it uses Chlorine Dioxide. It is different than Liquid Ozone. Both have their appropriate
      applications. Maybe Oxidation Tech can give you a comparison of the two.

    1. Ozone in water is a great disinfectant. The water has a high ORP (oxidation reduction potential) and will kill all pathogenic bacteria and viruses and leave no residual. That’s great. The water does not change other than the added ozone/oxygen. Therefore, the ability for that water to clean, cut grease, ect will not be changed, either better or worse.

      1. I’m not sure that’s true at all.
        Otherwise, why would aqueous ozone be used in laundry, without soap?

        Ie: those super-fluffy (and reliably white) hotel towels.

        1. In laundry applications, we would suggest using detergent with ozone. While less soap and detergent can be used when ozone is used in water, ozone does not replace the need for detergent and soaps. Ozone replaces the need for hot water in laundry applications. This lowers your operating costs by eliminating the energy required for hot water. The elimination of hot water is the main purpose for implementing ozone in laundry applications.

  2. Does Ozone more effective is spray and less, or sprayed and then wipped off. In particular when using against covid-19?

      1. how much concentrated must be the ozone in water applied to a surface (as a spray) to inactivate pathogens?

  3. I still feel that a PPE should be used for spraying ozinated water on my plants to rid these plants of mildew. I generate ozinated water every day in my water bottling plant. I am just a little shy of spraying ozinated water on my plants, and my personal protection.
    Please reply with a for sure answer to this situation.

  4. How safe is it to spray onto a cloth and wipe areas? Does the ozone ppm concentration degrade significantly when going from a spray to a cloth then a surface, if so by how much? do you have validated tests to prove that the PPM on the surface is still potent?

  5. I have been working with zone for many years in mold remediation. It is imperative to understand the levels at which safe operation and effective sterilization can be achieved. ZAt high levels in the air, ozone can be very dangerous if breathed in. I strongly recommend becoming very familiar with all precautions and warning before executing any use. I have a small air/water unit that produces no more than 800g/hr. Setting the timer and calculating square footage and in case of water ounces if using the English standard of measure is indeed imperative. Otherwise it is a great method to clean. Best wishes to all in the future and please err on the side of caution.

  6. How liquid ozone is effective against coronavirus? In the light of recent events, this problem is more acute than ever, and perhaps a global solution is in your hands.

  7. Hello
    chethan from India
    How can i disolve ozone gas in to water to get liquid ozone. is there any specfic method? please advice

    1. We provide ozone water systems, and even a small ozone spray bottle.
      Let us know what volumes of water you are working with and we can give you specific equipment advise.

  8. Where to purchased please ? I lived in Florida. I used to have a Lotus counter top unit. Tersano do not sell them anymore. Could you help ? Thank you.

  9. I am from India. We would like to use Liquid Ozone in ulv foggers to disinfect office areas….Can you pls let us know if this is possible…where can I procure this system…We will need many systems…

    Also, if Ozone is sprayed in foggers – is it dangerous to people , if they inhale…


  10. Hi i want to use it in my pilates studio on rubber mats and equipment. I have got the ozone on tap now. Can i just use microfiber clothes to wipe and clean down with once I have sprayed or soaked my cloths in ozone?

  11. Dear sir
    From India. If i want to use liquid ozone to disinfect humans at working areas. how much PPM of ozone need to dissolve in water so that they should not effect by ozone from inhaling it.
    Can we use this method to disinfect humans. please suggest me sir.

    1. For disinfection ozone levels in water should be at least 2.0 ppm
      At this level, some ozone will off-gas from the water and could cause unsafe ozone levels in air. Be cautious of ozone levels in air.

    1. Ozone is generated as a gas. Any ozone generator will produce ozone gas that can be pumped into an enclose space safely. Ozone monitors can then be used to measure ozone gas in that space and control the ozone generator to the desired set-point.

  12. I am thinking in using liquid ozone for spraying costumers hands. when a costumer approaches to buy a watermellon or a fish, his hands should be sprayed with liquid ozone. So the desinfection should be an automatic process. What do you think of the idea?

  13. Hi. Will Ozone kill mould in the bathroom? Will it destroy pet urine odours as effectively as an enzymatic formula?

  14. Hi I have a question about using the spray bottle – is it normal to smell the ozone after you’ve applied it? Does that mean the ozone levels are too high or is this to be expected? Thanks look forward to your response.

    1. You should smell some ozone in air. Ozone will off-gas from the water and enter the air space. You will smell this ozone in air. Should not be a safety concern. Ozone in air is safe up to 0.08 ppm for long-term use. The human odor threshold for ozone is typically 0.2 ppm. Therefore, you can smell ozone in air at levels well below the safety limits.

  15. i work in a dental office
    and since the outbreak of corona the Dr. has started using
    ozonated water to sterilize everything…
    since then some of our camera lenses have become foggy and some of our equipment is malfuntioning
    my question is can this have anything to do with the ozonated water being used
    as disinfectant and at night he puts on two machines that emit ozonated air purifiers

    1. I would not suspect that ozone water for disinfection is causing any issues. Ozone in water is very stable and easy to manage. I would question the ozone air purifies. Ozone in air is reactive with rubber and plastic materials. This could damage sensitive seals on the camera for example allowing ambient air (with humidity) to cause your issues. Use ambient air ozone generators in these applications with caution. Or obtain ambient ozone meters to measure and regulate ozone levels in air to safe, and sustainable levels.

  16. I wish there was some research on breathing in ozonated water mist and that it is safe for humans? Any guidance on that?

    1. It is mostly irrelevant to do this research. Ozone at any substantial level in water for antimicrobial use (above 2.0 ppm) used as a mist will off-gas enough ozone into the air space that the level of ozone in the air will be unsafe to breathe (above 0.3 ppm). Therefore, the safety of the mist itself is moot.

      1. Sorry Joel, I am somewhat confused. Your reply to Jennifer about smelling the ozone in the air after using the spray bottle is that the “smell ozone in air at levels well below the safety limits.”. But your reply to Marcos on “breathing in ozonated water mist” is that the “mist will off-gas enough ozone into the air space that the level of ozone in the air will be unsafe to breathe”. Both these 2 response of yours sound contradictory. Have I interpreted wrongly?

        1. Ozone in air is in the gaseous form. The SB100 spray bottle produces ozone levels of 1.5 – 2.0 ppm in water and sprays this water at a very low pressure. When we test ozone levels that have off-gassed from this low-pressure spray we find ambient ozone levels in air below 0.05 ppm = very safe.

          To create a mist from water a higher pressure spray is required, or a shearing action from the spray nozzle will be required. Within this action, we have always found that a great deal of the ozone that was dissolved in the water off-gasses from the water. For antimicrobial interventions, an ozone level in water of 2.0 ppm or higher should be used if a short contact time of 3-seconds or less is desired. At high dissolved ozone levels if we shear (off-gas) much of ozone gas from the water so it enters the air space it will reach levels of ozone greater than 0.3 ppm.

          However, we are always interested in hearing someone else’s experience. There may be spray nozzles that work better than what we have tested, or other mechanical equipment. We would be glad to hear from other experiences.

          1. Joel,
            I am interested in using a concentrated ozone for cleaning sports equipment. I want to mix it with water in a battery operated sprayer or a fogger. Both products are manufactured by Ryobi. Could you tell me more about my delivery methods/ mixtures, and recommend what is best?

  17. When using liquid ozone to sanitize tanks, does the liquid need to touch all surfaces or is it good enough to spray the liquid on the tank floor and allow it to offgas to sanitize the walls and lid?

    1. The water should cover and coat all surfaces. When ozone is dissolved into water all of that water has a high ORP level and will inactivate bacteria through the lysis reactions. Ozone gas however is a special consideration. The gas is not electrically charged, only the ozone molecule has the potential to create the oxidative burst required for cell wall lysis. Therefore, the ozone molecule must react near that bacteria. This may happen but is not guaranteed. Therefore, ensure the water contacts all surfaces for best results.

  18. Can it be ingested? Many in my workplace filled up spray bottles several weeks ago and are still using them. But isn’t it just water by now. That’s 96 half lives in one day and it has been 2 weeks.

    1. If using the SB100 ozone spray bottle or similar alternative this is fine. The water is converted to ozone as it sprays out of the bottle.

      If filling a spray bottle with ozone water this will not work as there is no way to know how fast the ozone decays in the bottle. It is not an option to use ozone water in a spray bottle and carry that around hoping the ozone stays in the water.

    1. Ozone in water is not toxic to plants and will not cause any harm. However, if ozone off-gasses from the water while it is sprayed on the plants the ozone in air is harmful to plants. Therefore, great care should be taken when applying ozone water to living plants.

  19. Good afternoon everyone,
    As rec centres begin to open back up to the public, we have been searching for different ways to help reduce the spread of covid-19 through our facilities. We have begun to use the Ryobi 18v fogger/mister device paired with the Tersano aqueous ozone cleaning solution to fog dressing rooms and touch points after each booking. Employees have been instructed to wear an N95 mask, with a clean shaven face, disposable rubber gloves, and eye protection while operating the fogger. Since we started using the fogger a few days ago, multiple staff have complained that they have a ‘sterile’ smell stuck in their nose for hours after their shift is over. The staff have used the Tersano product in conjunction with other cleaning products for a few years now, and we have not had these reports prior to using it in the fogging machine. I attempted to recreate what the employees were experiencing, but I didn’t find I was bothered me at all. Just curios if anyone else is experienced these issues in the workplace, or if I should be exploring other reasons for the complaints.

    Thanks, Jay

    1. Does Tersono add anything else to the water other than ozone? I know that has been the case as they would adjust the PH of the water. If so, I would question that.
      If you do have ozone in the water the fogger is using, that ozone in water is certainly almost all flashed off the water and enters the airspace as ozone gas. Depending upon the level of ozone in the water, you may easily achieve ambient ozone levels unsafe for people to breathe. My guess is you are exceeding the OSHA limit for ozone in air. If you wanted to verify this you could purchase a low-cost ozone monitor to verify ozone levels in the air. See link below for a good example.

  20. Hi can you tell me the concentration of ozone for the spray bottle unit, also for that unit is it just a electrode electrifier or is it a air fed electrifier Regards

    1. The SB100 provides 1.5 – 2.0 ppm ozone in water. It is shipped with an ozone test kit to verify actual dissolved ozone levels in water and verify this ozone level in water.

  21. Can you buy liquid ozone sprayer to use on dog urine in carpet? Will it get the stain out and remove the urine and or bacteria?

  22. Interested in ozonated water for sterilizing mushroom growing medium. Seems more efficient than steam sterilization and safer than chemicals. Research papers use up to 500 ppm gaseous ozone for mushrooms, seems like that is hard to do. What level of ozonated water would accomplish the same disinfection, and would that be safer than 500 ppm air?

    1. Ozone in water of 5-10 ppm would be sufficient in this application.
      However, it is more common to use ozone gas to disinfect these growing beds as the gas does a good job of permeating the porous surfaces and does not add water to the environment.
      When the room is cleaned out, and the growth medium is removed consider using ozone water for sanitation.

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