Ozone treatment & ozone gas hazards home page:

This article explains the hazards associated with use of ozone gas indoors as a "mold remedy" or as an "air purifier" or as a "mold killing agent".

While there are established uses of ozone in industrial applications and in certain sterilization applications, environmental testing experts and authorities such as the US EPA do not recommend use of ozone for mold treatment.

Use of ozone indoors can be hazardous and can cause oxidation or other adverse reactions with other materials and chemicals indoors.

Ozone Gas Hazard FAQs

These questions & answers about the dangers of improperly-used ozone and ozone generator hazards were posted originally at OZONE HAZARDS - be sure to read that information too.

On 2019-11-13 by (mod) - is UV light on AC coils useful?

UV light has useful applications in some systems but in my view the light is ONLY going to treat surfaces on which it shines. It is not and can not treat airborne contaminants since they don't hang around in moving air through the duct system. And the UV will only treat some (not all) biological contaminants - as we noted at HVAC SYSTEM ODORS

High levels of ozone are indeed unsafe as you will read in this article series;

However properly adjusted and used there should be NO detectable ozone smell in the air you breathe; if you smell ozone then the system isn't working properly.

On 2019-11-12 by Anonymous

Would you render your opinion about using UV lamps on AC coils in an HVAC system? It's my understanding that ozone is produced when these lamps are in use and I have concerns about the level of ozone produced and health hazards. Thank you, in advance, for your thoughts.

On 2018-06-27 by (mod) -

That sounds doubtful and extreme.

However there are some cleaning companies who specialize in removing odors from clothing.

Only if clothing were actually oxidized or damaged by ozone - very rare in my experience - might it be beyond salvage. That MIGHT occur with some synthetic fabrics.

Couches and other heavy upholstered items, on the other hand, can be impossible to deodorize if contaminated by mold or if damaged by ozone over-dosing.

Before throwing away anything costly like a couch it would be smart to do some odor source detection to be sure that the to-be-tossed item is in fact the culprit.

Please see SMELL PATCH TEST to FIND ODOR SOURCE

for an inexpensive and easy way to test various surfaces and materials to be sure you've correctly identified the odor source.

On 2018-06-27 by Ilya

I tried to Launder it couple times, no results.
So basically my couch and my clothes are all gone.

On 2018-06-27 by (mod) - stuff smells after the ozone machine was run for weeks

Ilya,

Unless the ozone machine is still running, or has been off only minutes, you won't smell ozone from its operation as Ozone is so reactive and volatile that it disperses quickly.

But you could be smelling oxidized building materials that are now off-gassing. Sometimes that can continue almost indefinitely unless the materials are either removed or for those that can be, sealed.

If that's the case, the apartment was overdosed in ozone.

Laundering should help with clothing.

On 2018-06-26 by Ilya

My landlord put a big ozone machine in the middle of the room in 670 Square feet apartment.
Not sure of the model, but it was laying on a cart and looked big.

It ran for about 35-40 hours nonstop.
It’s been a week and when I walk in inside the apartment it smells ozone.
All cloth and pretty much anything made from fabric smells as ozone.

What should have been normal hour usage for my apartment (approximate)?
Is there a way to restore my cloth back to normal smell?
I tried to Launder it, but it still smells.

On 2017-05-16 by (mod) - Regarding ozone toxicity in my car

I cannot comment on what a dealer can or cannot do without your consent, as that's more of a legal question. My opinion is that when I drop my car off at a dealer for repair expect them to do what's necessary and to do it responsibly and competently.

It's possible if there is a strong chemical odor in your car that was not there before and if you know that the car was treated with an ozone generator, that some of the materials in the car interior may have been oxidized to the point of outgassing a terrible odor.

If that's the case then it is not easy to get rid of that odor although sometimes a combination of ventilation and fresh air and sunshine can help.

Ethio the problem persists then I suggest using a

SMELL PATHC TEST KIT ... search this website for that phrase using the search box just above...

To see if it is possible to identify a particular material in the car that is the primary order Source - such as carpeting or carpet padding.

If we are lucky the other source is a material that can be easily removed and replaced.

On 2017-05-16 2 by Chris Ann

Regarding ozone toxicity: Dealer did unnecessary repair on my 2016 Honda Pilot. I brought it in for a smell that was coming from the air system when I used defrost/remote start, etc

. I did not report any cabin smell, but odor that only came through the air vents specific to using the defrost. The car is new and has never had any cabin odor and the service order was very detailed before I left in spelling out the problem. For some reason, the tech used an ozone generator in my vehicle.

When I picked it up Friday afternoon, it smelled like a combo chemical/masked new car smell, was only drivable with windows down. I assumed it was related to the work they did and tried to air it out over the weekend, but it remained undrivable. My 16yr old daughter has asthma and allergies and I have allergies.

Headache, irritated throat, and irritated breathing from being in the car for 20 mins. Brought the car back to dealer yesterday morning specifically about the smell, not knowing they had done the ozone generator until tech told me today. Tech said that he "didn't know there would be a smell after" and apologized.

He actually said that I must be "sensitive" to the smell. Undrivable smell confirmed by myself, husband, daughter, service rep yesterday morning, and service tech this afternoon. My questions are:

1. Can the dealer do an ozone generator treatment without my consent?

2. Does it sound like they over-ozoned or did it incorrectly based on the strength of the odor? Low 80s today and they have it out in the sun with windows open and it's even stronger smelling with a hot interior.

3. The entire interior is cloth, foam seats, carpeting, etc, a car! From what I have read here on the various FAQ, it seems that it is likely that oxidation of the interior materials is something that can't be corrected?

4. Is there any way for them to fix it? How long would it take?

5. Should I have the levels measured?

6. Is any level of exposure acceptable, not to mention a teen with asthma?

I am just looking for some insight and thoughts. I believe that it make be irreversibly damaged, but do I expect that they will just say, oops and send me away? (Going into car dealer questions, sorry.) Again, just trying to educated myself before I hear from them with whatever they might propose so I know if they are being truthful and I agree to anything. Thank you so very much.

On 2015-06-01 by Anonymous

Is Formaldahide( I can't spell good) part of Ozone?

On 2015-06-01 by Anonymous

how to detect Famaldihide?

Question: I and my cat are suffering symptoms of ozone exposure?

What do you do if you think you and your cat are suffering symptoms of ozone exposure in your home? I think it is from an air purifier I removed, but sumptoms persisting the next day. - Anon 7/31/11

Reply: cats versus people & respiratory irritants

Anon,

Consult your doctor and

see 3 STEPS to ASSESS POSSIBLE HARM from OZONE GAS O₃ EXPOSURE

Anon, high levels of ozone could be a respiratory irritant and at quite high levels more dangerous. But ozone gas itself is so highly volatile that once the ozone source is removed, you and your cat would no longer be exposed to ozone in that home - in minutes to hours the ozone will have become depleted - gone.

Therefore if you and kitty are suffering it makes sense to see your doctor who may in turn refer you to a pulmonologist.

In my OPINION the potentially harmful effects of any indoor air quality hazard may be greater for pets like your cat than even for most humans - that's because the pet

- has smaller body mass
- has a higher respiration rate
- may be inhaling dust and irritants found closer to floor level

So kitty may merit a trip to a catpulmonologist - or at least a veternarian who has experience with animals suffering from respiratory distress

Question: Ozone enthusiast (or seller) objects to ozone warnings

Ozone is more of a threat to current businesses who depend on ozone-less products such as chemicals or standard purification than it is to humans. If used properly, O3 is very safe. Theoretically it CAN be harmful. Fact is, there has yet to be proven incident in the past 100 years of O3's use to my knowledge.

Obviously you wouldn't run it all day and share the same environment with 03 just as you wouldn't spray fragrance or a chlorine based substance in the air and hang out in it. I will agree for household air purification it can be touchy due to misuse. As a gas o3 should be exhausted form the living environment.

However, For cleaning surfaces, meat, produce, toilets, hands, etc..... OZONE is perfectly safe. If contained in water, it is perfectly sensible to be used around the house, in a restaurant, food processing facility etc. And. it can be used for a prolonged period of time. - Anonymous 8/1/11

Reply: See the expert citations

Ozone at high levels is more than theoretically harmful - take a look at the authoritative citations earlier in this article and also at the bottom of this and our other Ozone articles.

Those sources are clear about the hazards and cite sources such as the U.S. EPA who cannot be considered " ...businesses who depend on ozone-less products such as chemicals ..."

Using ozone as a "magic bullet" to "cure" toxic mold problems is an incorrect approach that risks not only the consumers' money but when mis-used, creates additional problems by oxidizing certain building materials and causing worse odors than before.

We agree that there are safe and appropriate uses of ozone, properly selected and applied. It is not a mold remedy nor a magic bullet.

InspectAPedia is an independent publisher of building, environmental, and forensic inspection, diagnosis, and repair information for the public - we have no business nor financial connection with any manufacturer or service provider discussed at our website.

We are dedicated to making our information as accurate, complete, useful, and unbiased as possible: we very much welcome critique, questions, or content suggestions for our web articles. Working together and exchanging information makes us better informed than any individual can be working alone.

Question: Ozone generator in my marine salt water tank

I personally use an ozone generator in my marine saltwater tank i dose approximatly 35 mg per Hr. for 4 hrs. per week with a calcium reactor dosing at 20 Mg per Hr. I use large charcoal fines in a sock filter over the overflow canister off of the protein skimmer to eliminate the odor. (IT WORKS GREAT)

By the way screw the FDA they will approve any drug on the market only to take it off of the market in 5 years or less with major law suites. - Tuffguy 9/26/11

Reply:

Tuffguy, in a marine tank using ozone is a completely different process than using an ozone generator to "clean" indoor air. I appreciate that we may not always be happy with the level of FDA enforcement and the difficulties faced by that agency, but nevertheless, there is an absolutely stunning abundance of authoritative research on this topic and not much room left for wild arm-waving.

Question: how long will air quality issues last in an overexposed ozone treated home?

Can a house that was overexposed to ozone approximately four years ago in an attempt to kill an animal odor still be subject to air quality issues today? If so are there tests that can be run regarding this? - DP 10/18/11

Reply:

DP, I don't know. All of the ozone over-oxidation issues I've investigated were so bothesome to building owners/occupants that they were dealt with in weeks to a month or so by finding and removing oxidized materials that could not otherwise be salvaged, cleaned, or re-coated with a suitable sealant.

However I can report that people with whom I've consulted on this matter have asserted that once certain materials have been over-dosed with ozone sufficient to damage the material (apparently by a form of oxidation), when bad smells ensued, they did not appreciably diminish until the problem was solved.

So I agree that one could imagine that a home overdosed with an ozone generator several years ago, if that is indeed what happened, may still have odor sources if nothing was done in the mean time to address the problem.

Question:

After breathing a high dose of Ozone, is it possbile to absorb it and unrinate it out? As after breathing it in at my workplace, I believe I could smell it in my urine. - Anthony 12/19/11

Reply:

Anthony, see Can we detect dissolved ozone in human urine? in this article.

And if you have a concern for personal exposure to high levels of ozone,

see 3 STEPS to ASSESS POSSIBLE HARM from OZONE GAS O₃ EXPOSURE

Question: sewage sludge, smells, illness, we need diagnostic help for our home

4 years ago my neighbor hauled raw sewage sludge. my house still reeks horrid. we vomited & dirreah for 9 months. our eyes & throat still burns. how can we find out what happening to our beautiful farm home. is there any advice u could give us to help same our home. We were forced to move off our farm. any advice. - Karen Ellerbach 2/26/2012

Reply:

Karen it sounds serious enough that you should find an expert to inspect, test if needed, and diagnose the problem as well as to specify the cleaning or cure for your home.

From the brief comment you've offered I suspect that the home was not properly cleaned and that at this point professional investigation, probably some demolition and cleaning and sanitizing are needed.

You should also consult your doctor if you have not already done so.

Question: can ozone treatments in apartment be dangerous to the apartments above or below?

If treating an apartment with ozone to remedy a odor, can it be a hazard to unit above or below? - Brian 1/20/13

Reply: possibly, though unlikely. Here are some factors to conside:

Brian,

No one can give a definitive answer to your question with what basically amounts to no data whatsoever about the method of ozone treatment, its extent, levels reached, air movement between apartments, apartment contents, exposure duration and other factors that would be involved such as cross-movement of air between the two spaces by various means including convection currents, pressurization differences, or common-shared HVAC ducting.

However it seems unlikely.

Only if occupants of an adjacent area actually smelled ozone during the treatment time would the question seem likely to arise.

Question: how to treat ozone exposure

(May 8, 2014) JORGE said:

HOW TO TREAT A PERSON inhaled OZONE? AND THIS WITH CHEST PAIN AND LACK OF AIR 2 WEEKS?

Reply:

See your post and our reply at inspectapedia.com/sickhouse/Ozone_Treatment_Warnings.htm

Question:

(Oct 20, 2014) B bennett said:
I am looking for part of an article that describes the "ozone created problems - can lead to more problems than before". A contractor used two large ozone generators in our house months ago and there is still something in the air that we cannot tolerate.

Reply:

Suer Mr. Bennett.

These articles describe ozone-created problems such as the oxidization of building materials leading to additional odor complaints as well as health concerns from over-exposure to ozone.

...

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Continue reading at OZONE HAZARDS or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see these

Recommended Articles

• MOLD CLEANUP GUIDE- HOW TO GET RID OF MOLD - home
• OZONE HAZARDS - home
• SMELL PATCH TEST to FIND ODOR SOURCE

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OZONE HAZARD FAQS at InspectApedia.com - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.

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INDEX to RELATED ARTICLES: ARTICLE INDEX to BUILDING ODOR DIAGNOSIS & CURE

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Citations & References

In addition to any citations in the article above, a full list is available on request.

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