Ozone air, odor, car or mold treatment FAQs:

Questions & answers about using ozone to treat indoor or car smells or mold. This article provides questions and answers about the use of ozone generators or ozone treatments for odors, smells, or mold in buildings, cars, or other vehicles.

This article series provides government and other authoritative warnings about using ozone generators and ozone air purifiers in buildings to "purify" indoor air or to "kill mold" in buildings. We give a definition of ozone or O₃, we explain what problems can arise when using ozone generators to try to get rid of odors indoors or to try to kill mold.

FAQs About Using Ozone for Treatment of Indoor Air: Respiratory System

These questions & answers about using ozone to get rid of odors and smells in homes, offices, cars, trucks and RVs were posted originally at OZONE MOLD / ODOR TREATMENT WARNINGS - be sure to read that article.

This quote from a reader's email pretty well sums up what happens if you overdo it when using an ozone generator indoors to try to "kill off" odors:

It's a long story, but I used a high powered ozone generator in our house, to get rid of skunk smell. Now I can't get rid of the left over nitric oxide, or whatever odor or gases, that linger in our house.

I have been leaving the windows open every day, with running the heat on high (85 degrees) at night, to try to force off-gas the odors/gases.

Watch out: We have investigated a number of cases of misapplication of ozone generating machines both to "kill mold" (no good, you're leaving toxic or allergenic particles, and you haven't corrected the reason for mold growth in the first place). We have also investigated several cases of excessive ozone-use to try to remove odors from buildings, including fire or fireplace smells, mold smells, pet or animal smells, skunk odors, smoking odors, etc.

Here is another similar case:

Our dog was sprayed by a skunk and then ran through our house. The skunk smell was terrible. We hired servpro to get rid of the odor. They used the ozone machine and although is helped to get rid of the skunk smell, we now have a lingering chemical smell.

We have had our walls, ceiling, furniture, rugs, clothes, bedding all professionally washed but the smell still remains. What do you recommend? BTW, we live in eastern massachusetts. Thanks for your time and for this service you provide. - S.M.

On 2021-04-07 - by (mod) -

@Laura,

please read OZONE MOLD / ODOR TREATMENT WARNINGS

and perhaps the other articles in this series.

Consider that some sources of odors won't be magically removed by ozone depending on the source and its properties, location, quantity, etc. Permit a crude example:

If there is a dead skunk under your house, no amount of zone oxidation of household surfaces is going to fix that problem.

On 2021-04-06 by Laura

we are 90 percent sure it’s from candles . That being said I’ll check into this patch test . I thought ozone could pretty much get rid of any smell?

On 2021-04-06 - by (mod) -

@Laura

I suspect that if people would follow the ozone generator manufacturer's recommendations, taking into account the building or treatment area volume, and stopping as soon as the manufacturer says is safe - or sooner - that's keeping on the safe side.

If you SMELL ozone the area is unsafe and needs prompt fresh-air ventilation.

And frankly, I would not use ozone at all to address an"odor" or "fragrance" before first tracking down the odor source to see if I could simply remove it. Often the SMELL PATCH TEST KIT we discuss in this article series can do that successfully, quickly, and without any real expense.

On 2021-04-06 by Anonymous

@Laura,
The home is 50 years old. No new construction either . Most recent paint job was 2 years ago .

On 2021-04-06 by Anonymous

@Laura,
How can we ozone safely ( not overdoing).

On 2021-04-06 by Laura - we want to ozone safely

I bought a home ( nothing new In it). No new paint or floors. There is a fragrance smell we can’t out. Cleaning company cleaned top to bottom. Helped a little . Said lots of soot from scented. candles most likely .

This fragrance gives me headaches and brain fog. I can’t tolerate .

We want to ozone safely . 1300 sq feet . Smell is in all rooms but one. There is nothing in home excerpt small leather love seat and a book case .

We were going to put those in garage during ozone. How much should we do the rooms for ? I’m super sensitive and so we will likely air out for days to weeks after .

No people nothing in home except the two things mentioned above. No carpets .

On 2020-09-22 by (mod) - how to remove the residual smell from over treatment with an ozone machine.

Sandy

You'll want to see the other articles in this series, at the suggested at Recommended Articles.

There you'll see that unfortunately when a home is over-treated with ozone there absolutely no way to remove that over-treatment odor without removing the odor-source.

That means finding which materials were oxidized (carpets, upholstery, padding, etc) and removing them.

No "cleaner" will have one iota of benefit.

On 2020-09-22 by Sandy

Hello. I have a question about how to remove the residual smell from over treatment with an ozone machine.
I purchased a house 3 months ago that was updated with new laminate floors, paint, and appliances. When the “fresh smell” wore off, I discovered that the sellers were masking the smell from cigarette smoke of the previous owner

I had a company clean and sanitize the air ducts and furnace. A few weeks later the cigarette smell returned.
The air duct cleaning company returned and used an ozone cleaner. The cleaner ran 2.5 days. I believe they over treated my home because now I have an odor worse than the cigarette smoke. It smells like a fire or burning wire. The smell is very intense.

I have tried several cleaners to no avail. Please, what can I do to remove this smell from my home?

On 2018-08-02 by (mod) - ozone treatment of car caused lasting smells

Anonymous by private email said:

Hello, my name is ..., I found your website and I had a few questions. I had to have my car's seats and carpet and ceiling fabric reupholstered due to an ozone treatment that caused a toxic smell that wouldn't go away.

Would you say this is because the auto detailer overdid the ozone and thus it oxidized the fabrics in my car?

It even reeked up my dashboard but I haven't replaced my dashboard because that would cost $3000 plus an additional $1000 for labor. On your website it says
"polyurethane, the presumed coating on some wood floors, can be affected by ozone exposure."

And then I looked up polyurethane and wikipedia says "Flexible and semi-flexible polyurethane foams are used extensively for interior components of automobiles, in seats, headrests, armrests, roof liners, dashboards and instrument panels."

So I think the ozone also oxidized the polyurethane in my dashboard.

I'm just trying to get a better grasp on the science behind how ozone oxidizes carpet and seat fabric and dashboard materials. And thus gives them a toxic smell that burns your lungs and eyes and causes headaches.


MOD replied

It is certainly possible that over-dosing with ozone can oxidize polyurethane foam, vinyl, other plastics, and some paint coatings including materials used in cars. I have had a constant stream of complaints from car owners as well as home owners about over-dosed ozone-treatments that result in persistent odor problems.

You've replaced a lot of material in the car already. I agree that it can be difficult to decide when to spend more and when to give-up on a problem like this one.

Sometimes the odors will subside, with ventilation of fresh air and sunlight; or some materials have to be replaced entirely. Replacing an entire dashboard sounds too-costly to me. Before even considering such a move, insurance-covered or not, I would want to try the smell-patch procedure to confirm that I'd correctly identified the odor source.

Search InspectApedia.com for SMELL PATCH TEST KIT if you want to try that.

On 2018-07-22 - by (mod) - running an ozone generator in our new Subaru caused headaches and new smells

There is a significant risk of making the chemical odors worse in the car or even of destroying it by an ozone overdose as we explain in this article series.

In clear sunny weather try leaving the car in the sun with windows open. Most new-car vinyl odors dissipate.

On 2018-07-22 by Adelle

I bought a new Suburu about 9 months ago. It had a strong new car smell that has mostly dissipated. My husband is very sensitive to odors and says that he is still affected by the odors in the car.

They gave him a headache after a 5 minute drive. I was considering using an ozone generator to remove the odors but now wonder if I might just make things worse. Any thoughts?

Question: What machine or service would be effective in removing toxicity left behind by an ozone generator?

(May 15, 2014) Jeff said:

What machine or service would be effective in removing toxicity left behind by an ozone generator? How to test the air and materials for toxicity if no smell is obvious? At what point is it safe to reuse materials and room? Thank you.

Reply:

Jeff:

I can't name such a machine and don't know one and doubt that such a machine exists, considering the possible causes, effects, & sources of over-dosing an area with ozone treatment.

You can

- clean surfaces that are washable

- dry clean or launder soft goods

- use our Smell Patch Test Kit procedure to identify the prime offending materials that need to be removed completely like oxidized carpet or carpet padding or upholstered furniture -

There is no machine one would put into the room that would "make it safe"

The ozone itself is gone quickly once the machine is off and removed. The odors that remain are from oxidized materials.

Reader Question: Smell from burned pot of baked beans, carpets cleaned, used an ozone machine, now the house smells horrible: I can't find the problem

8/19/2014 Michelle wrote:

Hi My name is Michelle and I just got off with you. The carpet person agreed to come out and only use steam water. I am happy about this and hopefully it takes care of the smell.

Reply:

Super, Michelle. Do let me know how that works. Your complaint was that after the carpets were cleaned there was a bad smell that got worse when you ozone-d the house. You added that because of high outdoor humidity and temperatures (South Texas) you didn't want to ventilate with outdoor air.

If he will tell you the brand and product that was used that included a scent I'd be interested in taking a look at that as well.

Reader follow-up:

I returned the ozone generator and I bought some activated carbon. Have you heard of that? A restoration company told me to try it. I put them in Styrofoam cups fill about 3/4 and put them all over the house. One in each bedroom and 2 in the larger rooms. Let me know what you think. I will keep you posted so someday you can pass the word to others.

The incident happened 2 months ago and due to the humidity, I feel as if it's working against me. Once October is here, the windows will be open all day and night. Hopefully that solves the problem.

Reply:

Unlike the ozone, the activated charcoal won't hurt a thing (unless you spill it and make a mess) and it will absorb SOME odors. However more likely if you observe a reduction in odor it will be from a combination of dissipation and ventilation

. I'm doubtful that activated charcoal in cups on floors can possibly remove any substantial odor source any more than waving the vacuum cleaner wand in the air in the kitchen can pull out dust bunnies from under the couch.

It wont' hurt though. Keep me posted.

Reader follow-up:

Do you think the smell will go away eventually with time?

Reply:

I just don't know. I would expect the odor to dissipate - that is diminish with airing out and fresh air.

But I've had complaints from folks who ozone-oxidized synthetics or foam that smelled for months until the material was tossed.

If we're not sure we've identified all of the odor sources we're flying blind - or holding our noses.

Reply:

Have some good news. I noticed my kids rooms smell worst and the odors are coming from their room. I just walked into their closets and found that socks, formal clothes and anything with that polyester or padded texture was the source.

I am washing all their clothes and will steam the carpets with hot water. I can't believe it, You are so right about trying to identify the items. I walked outside and clear my nose and then went into each room. I am happy and working on this at the moment.

Reply:

nice going. And thanks for the follow-up.

Question: odors remain after thermal fogging and ionization treatments

(Jan 10, 2015) Anonymous said:
After using servpro to cleanup after smoke damage to our home , the thermal fogging and ionization odor still remain strong ? Is this dangerous to my Family ?

Reply:

Anon:

Ionization treatments, in concept related to ozone treatments, attempt to remove some airborne particles or possibly molecules by causing them to retain an electrical charge that in turn causes them to plate out on building surfaces. This procedure cannot remove an odor source however.

I'd start by asking the company what treatments they used and then I'd take a look at the MSDS for those chemicals.

I'd continue by determining if the treatments were applied in accordance with the manufacturer's instructions.

Question: ozone to remove protein smoke odor, now strange odor remains

(Feb 21, 2015) Michael said:
My house was cleaned with ozone in order to remove the protein smoke odor. It was cleaned and re-painted as well: ceiling and walls. Now I have strange odor, which is not a smoke

. I suspect the oxidants odors coming from surfaces. It is clear how to remove the odor from the carpet - replace the carpet. However, I do not really understand how to remove it from the walls. Should I re-seal and re-paint the walls? If yes, what paint should I use?

Reply: what is in smoke & why odors remain after an odor-treatment program

Michael,

Really? "Protein smoke odors" ?

Since you describe an odor complaint that remains after a post-fire treatment it is most likely that the odor is coming from one or more building surfaces. People's complaints of odors that remain or that are "new" after post-fire odor-treatments typically come from one of two underlying sources:

Surfaces or materials that have received deposits of burned materials have not been adequately cleaned, sealed, or removed and are continuing to release molecules (or even particles) that smell.

The treatment itself, if it was not properly conducted, can produce new odors and smells from a sealant coating or from over-dosing with ozone as is discussed in this article series.

Therefore, before using an odor sealant (such as is used after a fire) and before repainting, you might have better and more economical success by identifying the odor source. Try the easy smell patch test kit described at

SMELL PATCH TEST to FIND ODOR SOURCE

When you've identified where the odors are coming-from you have a much better chance at a successful odor-cure.

(Feb 23, 2015) Michael said:
In fact, what I have done is a kind of partitioning test. I removed my loveseat and chair from the room, which was affected by smoke and further ozone and a chemical cleaning treatment done by professionals, and put inside of the garage.

Garage is a cold place that was not affected by smoke. After 1 week I have smelled this furniture and discovered that I have similar smell in the rooms (specifically where carpet is.

I believe that I need to really push my insurance adjuster to cover the carpet replacement.

This way, one of the major suspicious factors will go away. My air ducts were sealed by ServPro. I hope this will take care of another factor that could potentially affect the air.

What is weird is that kitchen cabinets are producing a unique odor, which is probably a combination of cleaning chemicals with ozone that is still doing outgassing.

Reply:

Michael: I'd still do some further smell-patch testing work as you may find that treatment either left some surprising surfaces smelling from inadequate cleaning or sealing, or if ozone was used it may have oxidized materials causing new odors to emanate.

Question: reader warns against ozone generating devices

Janine said:

DO NOT LET OZONE GENERATING DEVICES INTO YOUR HOME NO MATTER WHAT

Ozone's Impact on Public Health by Charles Weschler. specifically pages 7,8,9, and Table 1 for reaction products of household materials and ozone.

Our home was treated with hydroxyl and ozone generators for smoke odour. Rubbers, plastics, items with skin or cooking oils, among others, were visibly and materially degraded ("melted",embrittled,discoloured,)

On contact with items,surfaces and air in our home,we suffered irritative symptoms,and became ill and chemically sensitized,eventually having to abandon it and all our belongings.

The restoration industry is decades behind the current and available science - in 21 months have not been able to produce a damage assessment and restoration plan that addresses all the issues of material degradation due to indoor ozone chemistry, leaving us owning a house we cannot live in.

We have no assurance that the sources of our health problems will be removed and the house be restored to pre-loss, un-ozoned condition.

All scientific, government and health organization information confirms the damage and health issues, even industry organizations. The insurance industry does not want to acknowledge these credible sources. We have a lot more information -and pictures - anyone who has had this type of experience needs to speak out.

The use of these machines has to stop, especially as their use is endorsed by the insurance industry, homeowners are not warned of the potential for material damage(some is non-visible) and the toxic by-products left behind, and considering there are no guidelines for the restoration industry to remedy the damages their machines cause.

The "certified" restoration professional treating our home for smoke odour had no knowledge of harmful by-products from the ozone reactions he was promoting to "clean" the air.

Reply: properly-used ozone is effective for some applications but is too-often over-used, causing trouble

Janine,

While we have published various reader complaints about mis-application and over-dosing of ozone treatments that result in further IAQ or odor or even health complaints, there are valid and effective uses of ozone, provided that the process is properly applied and monitored by people who know what they are doing and providfed ozone is used where and how it works.

Ozone is not a panacea for odors and smells in buildings and unfortunately too often it seems that people think that if some is good, more is better, overdosing and oxicizing and creating more trouble than before. In my OPINION.

[The reader cited the following]

• Weschler, Charles J. "Ozone's impact on public health: contributions from indoor exposures to ozone and products of ozone-initiated chemistry." Environmental health perspectives (2006): 1489-1496.
  
  Conclusions: Indoor exposures to ozone and its oxidation products can be reduced by filtering ozone from ventilation air and limiting the indoor use of products and materials whose emissions react with ozone. Such steps might be especially valuable in schools, hospitals, and childcare centers in regions that routinely experience elevated outdoor ozone concentrations.

We do not completely share Weschler's conclusions because ozone itself is so highly volatile that ozone molecules don't tend to hang around long in buildings - unless an ozone generator is left turned on in the building itself.

It would seem that a significant number of complaints about "ozone" may in fact be generated by odors emanating from oxicized materials that were exposed to an overdose of ozone during building "treatment" for odors. - OPNION - DF.

Also see more complete research at

• OZONE MSDS [PDF]


• OZONE REFERENCES & OZONE GENERATOR INSTRUCTIONS

Question: the car we want to buy smells, the dealer says get used to it and says will use their ozone generator to fix the smell

(May 19, 2015) R. C said:

Firstly, thanks so much for providing this an excellent resource, there seems to be a lot of misinformation out there on the web on this topic. Your website, is the first that I feel I can trust.

I'm hoping that you can help advise. There is a car that I am interested in buying second-hand, and I was basically almost ready to hand over my cash. I tested the air-conditioning, and discovered a very strong source of mould smell.

The car dealer said no problem, every car has its own odour and is just something that you can get used to, and that in any case he'd use his ozone generator and that would fix it.

Also, some anti-mould spray was sprayed down the air vents. However, after reading several of your articles it seems like neither of these approaches is appropriate.

I'm still considering whether to buy this car or not. The car is about $2000 cheaper than a comparable used car which does not have a mould smell in the ventilation system.

Therefore my thoughts are: if I could say just take the car to a company that could guarantee complete mould and odour removal for say less than $1000, then I should buy the car.

Otherwise, I should just walk away and pay more for a car which doesn't have this problem in the first place.

What I've had difficulty working out from my reading so far is the likely commercial costs, and success probability in any removal attempt.

Would you buy the car?

Thanks in advance.

Reply:

Thank you for the vote of confidence R.C. We work hard to provide researched, authoritative and unbiased information, and we are strict about having no financial relationships that could jeapordize your trust. To that end, we also much welcome questions, suggestions, or critique.

About mold smells in cars, indeed that can be tough to get rid of, and it is in my opinion NOT something to ignore or just "get used to". We had a client, an audiologist who knew that they had mold in their offices at a problematic level - but no one working there was much bothered until a customer, a teenager who was asthmatic, came in for a hearing test.

Shut into the hearing test booth he went into anaphylactic shock in response to the MVOCs that were present at a high level. And even people who are not bothered by mold can become sensitized to it by exposure.

At inspectapedia.com/mold/Car_Mold_Catastrophe.php we illustrate a worst case moldy car, while
at
inspectapedia.com/odor_diagnosis/Odor_Diagnosis_Car_Mold.php you'll find a less scary recounting of finding and fixing mold smells in vehicles.

I would be *very* careful about relying on ozone treatments - that can sometimes create a worse hazard, as you'll see warned in the

article OZONE MOLD / ODOR TREATMENT WARNINGS. Best is to find and remove the moldy material - such as carpeting.

I am also a little cautious about "guarantees" to remove "mold smell" which itself is a claim that is a bit of a red flag since we need to remove the mold (the source) not the "smell".

I suggest the following: invite the seller to cure the mold problem for themselves - which also relieves them of the liability of selling a car that could be a problem for some users. The price can be adjusted upwards for the actual cost of the cure.

I would not buy the car without either having it satisfactorily cleaned or with the assumption that I might spend $1000. only to find that I was going to abandon the vehicle if that treatment was not successful

. It can take weeks or longer to be sure that a treatment is successful. Changes in humidity, temperature, and ventilation can mask or renew a mold smell if the moldy source was not removed.

Question: car dealer used ozone to remove smoking odor. Is there a lasting effect or hazard?

I am considering purchasing a used vehicle from a dealer. It came to them with horrendous odor from the previous owner that smoked heavily in it. They used on ozonator in it for 3 days. Should I be concerned about the lasting negative effects of that? - by private email, Anonymouos, 22 July 2015

Reply:

Yes if the vehicle interior has a plastic or chemical odor. You have not said whether or not the car interior smells. Check by sitting in the car with windows all closed. Note that changes in temperature or humidity may also affect odor levels in any inclosed space.

Perhaps not if the ozone treatment was not over-done (which is often the case)

Reader follow-up:

Would you mind elaborating, or directing me to a website that could help me understand the ramifications, so I can make a clear decision?

Reply:

Sure see CAR SMELL - Mold DEODORIZING - though the discussion is about mold odors the same issues remain for deodorizing other smells inside a vehicle.

Basically ozone is a highly reactive oxygen molecule that interacts with (oxidizes) most substances with which it comes in contact. If you over-dose a car interior, which is very easy to do as it's a small, enclosed space, with ozone, you may oxdize the interior fabrics, headliners, upholstery, carpets.

If that has happened you'll know because even if the original odor (say cigarettes) is no longer noticeable you'll smell a strong, pungent chemical odor.

Unfortunately once we've oxidized such materials the only effective fix is to replace them. This problem comes up in car deodorizing as well as building odors where carpets or other furnishings can be affected by over-dosing.

and see

OZONE MOLD / ODOR TREATMENT WARNINGS

Let me know if after reading those articles you have more questions.

Question: using ozone treatment to clean up heating oil smell / fumes after a spill indoors

I have been googling to try to find a question to a problem I have.

Someone broke into my cabin and stole a toyo stove I had in there.
Whoever it was left the fuel line on and about 250 gallons of home fuel flooded the area.

Insurance will handle the ground fuel clean-up. (Fuel ran through the floor and into the crawlspace-- and through the ground soil, pad.

As for the cabin itself, Insurance has said it will pay to replace everything touched by fuel.

However, they will be using ozone-hydroxyl treatment on the walls.
It has taken 7 months to settle this issue with insurance and so the vapors have set in the cabin all this time..

Can you tell me how effective you think the ozone-hydroxyl treatment would be?
The upstairs was not touched by fuel, however it did have vapor exposure all this time.

I would very much appreciate any comments you can offer.

Thanks,
Mary - by private email, kept private, 22 March 2016

Reply:

You or I would have to do further research, but I suggest you start by searching InspectApedia.com for OZONE WARNINGS where you'll see that very often contractors over-dose a building interior with ozone in the hope of eliminating a smell that has deeper roots - causing a serious new odor problem and greater costs than ever.

Question: my son put an ozone generator in the room for 6 hrs now a week later EVERYTHING smells horribly

(Dec 15, 2015) sharon kopple said:

My daughter painted her nursery with 5!!! coats of paint. my son put an ozone generator in the room for 6 hrs now a week later EVERYTHING smells horribly and gives us a sore throat. The windows are open .
We have had the clothes outside for 3 days, washed some. Nothing has helped. Please we are desperate to find a solution.

Reply:

Sharon, air out the room, use the smell patch test we describe to confirm the odor soyrce, and then you'll know if you need to remover oxidized carpet / padding, I'c repaint with a post fire sealant.

Don't do the ozone trick again.

OZONE MOLD / ODOR TREATMENT WARNINGS

Question: run gas heaters whike running an ozone air purifier?

(Mar 1, 2016) Thomas sapp said:
Can you run gas heaters whike running an ozone air purifier?

Reply:

"Can" meaning physically possible, of course. But, then, I don't run ozone purifiers, for reasons discussed in this article series.

 

Question: how high will ozone gas concentrations be under these conditions ... ?

2016/06/19 Bill said:

Here's a good question. In an apartment building, if there are three ozone generators that max out at 57 grams per hour (designed for 1500 sq foot usage) shock treating three 700 square foot completely unventilated suites on the same floor, with fan in suite, taped off while concentrating but untaped when the machines were removed (but fans left running in suites), then moved to 2-3 other suites on the same floor and started again...

How high do you think the concentration of gas could reach in the hallway, ballpark?

The easiest evacuation point for the gas must be under the front door into the hall, given the seals on doors+windows in suite.

Unsure of hallway square footage, likely 2-3000 sq/ft. Assuming that the generators were designed to maintain 6ppm+ in a 1500 sq/ft room, could they potentially reach 12ppm+ in a 700 sq/foot room?

How dangerous would such a hallway be, then? I realize there are a lot of unknown variables that make it difficult to judge, but I ask because I was made to set up these machines and was exposed to this hallway for 45-60 minutes, experienced confusion, stinging eyes, and now have lung irritation. I could smell the gas in varying levels in the halls but was told it was normal.

Confusion didn't help in stopping me from working in the halls. Employer screwed me really, really bad, I just don't know how much gas might have built up in the hall or how much I was exposed to.

Based on research, 1.5ppm for 2 hrs is confusion onset. Myself and a coworker experienced confusion, forgetting where we were going, what we had just done etc after 20-30 mins. I can't help but think that given the circumstances there must have been at minimum 1.5ppm in the halls in certain areas, more likely 3ppm+ if there were particularly bad areas?

Any information is helpful, thank you. I do have moderate lung irritation right now, constant fatigue, and was prescribed a long term puffer, something I've never had to use before. I had inflamed bronchi 4-5 days later when I visited a doc (Honestly did not understand the severity of the incident until then).

Thank you

For claritys sake, the front doors to suites were taped off from the hallway. The gas could be smelled as soon as the door was closed and I was taping them. Neither me nor a co-worker were told to open doors/windows to ventilate the rooms, or replace tape after removing the generators, so after concentration the space under the doors to the hallway was wide open (and again, the easiest evacuation point), approximately 3/4 of an inch, maybe a full inch high space between door and floor.

Reply:

Bill

The questions you raise and potential hazards you note are not something that can be honestly, accurately, professionally assessed from an e-text. One would need to be on-site, making visual observations, interviewing occupants, considering building history, construction details, layout, air movement - many factors - to reach any credible opinion.

Even claims of output of an ozone generator cannot be generalized to guess at the actual ozone concentration in air without more data.

I agree with more general observations such as your ability to smell "ozone" indoors. If someone can smell ozone then it's certainly plausible that they're being exposed to a too-high concentration of that gas to be safe.

Bill said:
Thanks for the answer. I expected that kind of reply, I know there's so many variables at play there. I figured the situation would need to be recreated in order to know for sure, it's truly impossible for any of us to know how much gas we were exposed to other than general observation on symptoms and the experience..

Appreciate it though, thanks again.

(mod) said:

If you had actual quantitative measurements - (the dose makes the poison) you'd want to see OZONE EXPOSURE STANDARDS at inspectapedia.com/sickhouse/Ozone_Exposure_Standards.php

Ozone is volatile - it doesn't stay around, but my point about being able to smell it remains worth considering. If you or people with whom you work are experiencing respiratory distress, lung complaints or similar worries it's worth mentioning the possible ozone exposure when consulting with your/their doctor.

Bill said:

I did contact my doctor. He didn't seem to be very knowledgeable about it. I was prescribed a long term corticosteroid inhaler, it must be helping because my lungs still feel awful and I've been using it for a week.

At the very least - there should be nobody walking the halls in which 3 unventilated suites are running commercial generators, without proper equipment, right?

Bit of background here. It made national news in Canada. After having done some research all week for mine and co-workers benefit, I still have few answers. Seems like ozone is a pretty grey area in general.

• CBC News, "Multinational company defends its use of ozone gas after Fort McMurray wildfire, ServiceMaster says ozone generators are 'a necessary part of wildfire cleanup'", 20 June 2016, original source: www.cbc.ca/news/canada/edmonton/multinational-company-defends-its-use-of-ozone-gas-after-fort-mcmurray-wildfire-1.3642991
  
  Excerpt: Some workers for the Fort McMurray wildfire cleanup say they were exposed to harmful ozone gas and other unknown airborne contaminants while working for a restoration company called ServiceMaster at the beginning of June.
• Warnica, Marion, "Fort McMurray wildfire cleanup crew says ozone machines made them sick, Ozone machines reduce odours by emitting gas that can irritate nose, throat, lungs", CBC News, 20 June 2016, original source: http://www.cbc.ca/news/canada/edmonton/fort-mcmurray-wildfire-cleanup-crew-says-ozone-machines-made-them-sick-1.3642987
  Excerpt:
  One man went to hospital and several others have reported feeling sick, after being exposed to ozone gas and other potentially unknown chemicals during wildfire cleanup efforts in Fort McMurray. CBC News has interviewed four workers and obtained accounts from two witnesses — all with firsthand knowledge of indoor cleanup work at four properties.
  
  Each described how both fellow workers and some residents returning to live in the city were exposed to ozone gas and other unknown airborne chemicals from ozone generators, which are a type of industrial air freshener that experts, Health Canada and the U.S. Environmental Protection Agency all say should not be used in homes or occupied spaces.

Comment:

(June 21, 2016) Bill said:

I will definitely be booking your pages for future reference as well. This site has some of the best info available online, thank you for collecting it.

Reply:

For space and to permit live links I moved our discussion to the current end of

OZONE ODOR TREATMENT FAQs at inspectapedia.com/sickhouse/Ozone-Treatment-FAQs.php

in a section titled
Question: how high will ozone gas concentrations be under these conditions:

Your questions are helpful. Thanks back to you.

Question: house ozoned to rid the odor neutralizing powder that was put INTO the furnace - smells remain

(July 19, 2016) Katherine Lyons said:

we had our house ozoned to rid the odor neutralizing powder that was put INTO the furnace and should not have been...what is the average time to ozone a 900 square foot house?

Reply:

Katherine I can't answer your question. I do not believe that "time" and "square feet" is enough to specify a treatment time, since we don't know the ozone generating equipment being used, the concentration of ozone that is being produced in the indoor air, the building air change rate per hour, the building layout, floors, and air movement patterns, nor the placement of the equipment, nor the problem that the ozone treatment was supposed to solve.

But as you will read in this article series, common problems with ozone treatments in buildings include

- mis-use of the ozone generating process: using ozone is not generally appropriate for building odor problems; finding and removing the odor source is more effective, reliable, and safer.

- over-dosing with ozone, resulting in oxidation of building materials and severe ongoing odors after treatment

It would be helpful if you could tell me what furnace problem was being solved and what "odor neutralizing powder" was put into the furnace, where and how it was applied, and what the product was.

You can also use the page top or bottom CONTACT link to send details or photos.

Question: 3 large machines used to ozone the house

(Aug 14, 2016) Anonymous said:
Hello, Our house is 900 square ft and there were 3 large machines to ozone the house.....the ozone started on friday night at 5:00 and ended sunday afternoon at around 3:00...the machines ran all of the time without stopping.

Reply:

OK Anon, but other than raising the concern of ozone over-treatment discussed in OZONE MOLD / ODOR TREATMENT WARNINGS, and the concern of mis-use of ozone to "cure" house problems such as mold or an odor source that's not been found, I don't see a question here.

Question: How do you protect electronics during ozone treatment?

(Oct 23, 2016) Jack said: How do you protect electronics during ozone treatment?

Reply: research on effectives of & control of corrosive gases on electrical equipment

Good question, Jack. Below I'll cite some research pertinent to the effects of ozone on electrical and electronic equipment. If you have additional citations and research or specific field experience with this problem, let me know.

IMO you'd need to either remove the equipment from the ozone treatment area or you'd need to wrap it in mylar (best) or heavy poly and seal it against gas intrusion.

• Muller, Christopher O. "Control of corrosive gases to avoid electrical equipment failure." Purafil, Inc., webpage: www. purafil. com/literature/control-of-corrosive-gases. pdf (1999): 1-13.
• Fare, Thomas L., Ernest M. Coffey, Hongyue Dai, Yudong D. He, Deborah A. Kessler, Kristopher A. Kilian, John E. Koch et al. "Effects of atmospheric ozone on microarray data quality." Analytical chemistry 75, no. 17 (2003): 4672-4675.
• Piasecki, W., G. Bywalec, M. Florkowski, M. Fulczyk, and J. Furgal. "New approach towards protecting electrical equipment insulation systems against Very Fast Transients." In 2007 Annual Report-Conference on Electrical Insulation and Dielectric Phenomena, pp. 89-94. IEEE, 2007.

Question: mattress smells after ozone treatment for mold

(Oct 12, 2015) Marlene said:
A ozone machine was used as part of a mold clean up in my master. Mold is gone, but the ozone machine has interacted with my mattress which is releasing a toxic byproduct that is nauseating.

Everything is removed from the room except four hard wood pieces of furniture, wood bamboo flooring and a flat screen TV.

Walls washed down and floors steam cleaned. Nauseating smell still exist. It's been one month that we have been unable to sleep in our room. Any further suggestions of how to get rid smell?

Reply:

You may need to apply a sealant coating such as those used after a building fire, sealing walls, trim, floor.

See MOLD SANITIZER, SPRAY, BIOCIDE USE GUIDE

Question: powdery substance found after ozone treatment for smoke odors

(Nov 6, 2015) Jean said:
An ozone machine was used in my apartment to remove the smoke odor left from previous tenant. The maintenance man set the machine up in a small bathroom, shut the door and left running for 8 hours.

I returned and their is white powdery substance everywhere. Is this substance toxic or dangerous? Should we take any special precautions?

Reply:

Jean I have no idea what the white material is - that'd be tough to guess from an e-text. Certainly it's unusual. Perhaps something else was going on.

Ozone itself will be long-gone the machine has been removed.

Damp mop or HEPA vac up the mess.

...

General Use of Ozone Generators nor Ozone Shock Treatments as a "Cure" for Building Mold or Other Smells & Odors is Not Recommended

Watch out:  Ozone is a highly toxic, oxidizing gas. It can be absorbed into the body via inhalation, skin or the eyes. It can also oxidize building materials. See the Ozone hazard and use warning articles listed at the end of this article.

Watch out: In-Home or "portable" ozone generators and industrial or "shock treatment" ozone generators not only fail to find and remove the source of mold or building odors, in addition ozone concentrations generated by ionic air purifiers can exceed (industrial) levels permitted by U.S. Environmental Protection Agency.

...

Continue reading at OZONE MOLD / ODOR TREATMENT WARNINGS - topic home, or select a topic from the closely-related articles below, or see the complete ARTICLE INDEX.

Or see OZONE ODOR TREATMENT FAQs-2 - more-recent questions and answers about using ozone to treat mold or odors in buildings, cars, boats, RVs etc.

Or see these

Recommended Articles

• MOLD CLEANUP GUIDE- HOW TO GET RID OF MOLD - home
• MOLD CLEANUP - MISTAKES to AVOID
• OZONE AIR PURIFIER WARNINGS
• OZONE HAZARDS - home
• OZONE MOLD / ODOR TREATMENT WARNINGS
• OZONE SHOCK TREATMENTS NOT RECOMMENDED

Suggested citation for this web page

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

Or see this

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

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