Massachusetts Real Estate


Removing Odors in Your Home With Ozone

Removing odors from a homeRecently, I sold a home in Medway Massachusetts where the previous owner had a couple of cats. When showing this home to my buyer clients, there was a very strong odor present.

We figured it was the cat box and that the cats may have gone to the bathroom on the carpets at one point or another. The buyers figured that with the cat boxes gone and the carpets cleaned the home would be odor free.

Unfortunately, this carpet cleaning did not do the trick and the cat odor remained. The buyers gave me a call and asked me if I had any words of wisdom.

My 1st thought was getting an ozone machine. In my experience an ozone system is one of the best methods to remove pet odors. An ozone generator will not only remove pet odors but other troublesome odors caused by mold and mildew, fire, water damage and others. Ozone is considered "natures deodorant" and can get rid of many types of nasty smells.

There are a few types of ozone generators. The most common types are UV and Corona Discharge. The UV generator is generally recognized as the better of the two versions. The biggest difference between the two is that the UV ozone generator has a more stable ozone output. The Corona discharge unit can be effected by the humidity levels in the home. The ozone that is made from a UV ozone generator is cleaner because it does not produce any nitric acids. The smell is also considered better than ozone produced by a Corona discharge model.

It is possible that some very minor odor problems can be taken care of by a home owner who purchases their own portable ozone generator and moves it room to room to room. In most cases, however, a professional would need to take care of the odor issue.

When the odor problem is severe a professional will do what is known as a "shock treatment". A shock treatment will introduce a highly concentrated burst of ozone into a larger area. When a shock treatment is done people, pets, and even plants can not remain as the ozone in such high quantities can be a health hazard.                                                                                                                                            

It should be noted that there is some controversy over the effectiveness of ozone as an odor remover. The Environmental Protection Agency (EPA) actually goes out of there way to dispel some of the beliefs that ozone removes odors. The information provided below is taken from the EPA'S website regarding ozone.

"There is evidence to show that at concentrations that do not exceed public health standards, ozone is not    Removing odors from a home in Massachusetts effective at removing many odor-causing chemicals."

  • "In an experiment designed to produce formaldehyde concentrations representative of an embalming studio, where formaldehyde is the main odor producer, ozone showed no effect in reducing formaldehyde concentration (Esswein and Boeniger, 1994). Other experiments suggest that body odor may be masked by the smell of ozone but is not removed by ozone (Witheridge and Yaglou, 1939). Ozone is not considered useful for odor removal in building ventilation systems (ASHRAE, 1989)."

  • "While there are few scientific studies to support the claim that ozone effectively removes odors, it is plausible that some odorous chemicals will react with ozone. For example, in some experiments, ozone appeared to react readily with certain chemicals, including some chemicals that contribute to the smell of new carpet (Weschler, 1992b; Zhang and Lioy, 1994). Ozone is also believed to react with acrolein, one of the many odorous and irritating chemicals found in secondhand tobacco smoke (US EPA, 1995)."                                                                                                                                                                                                                                                                   

Man coughing exposed to ozoneOk so maybe ozone generators don't remove the smell of dead people or formaldehyde. Hope I don't ever have to deal with that one!

In my experience, I have seen ozone work as an effective treatment of pet and other common household odors.

While anyone can go to the store and buy an ozone generator, there are health consequences worth noting. 

According to the EPA, fairly low amounts of ozone can cause chest pain, coughing, shortness of breath, and, throat irritation.

Ozone may also worsen chronic respiratory diseases such as asthma and decrease the body's ability to fight respiratory infections.

People vary widely in the health effects to ozone. Healthy people, as well as those with respiratory issues, can experience breathing problems when introduced to an environment with ozone.

Bottom line if you have an issues that you have not been able to solve with other cleaning methods you may want to consult with a professional who deals with ozone treatments as a method of odor removal.

Thinking of selling your home in Metrowest Massachusetts? Here are a couple of articles to help get your home prepared for the market.

Low cost home improvements when selling a home

Preparing your Massachusetts home for the Spring selling season


About the Author: The above Real Estate information on Removing odors in your home with ozone wasRE/MAX Executive Realty Metrowest Mass provided by Bill Gassett, a Nationally recognized leader in his field. Bill can be reached via email at or by phone at 508-435-5356. 

Have a home to sell in Metrowest Mass? I have a passion for Real Estate and love to share my marketing expertise! 

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I service the following towns in Metrowest Massachusetts: Hopkinton, Milford, Upton, Southboro, Westboro, Ashland, Holliston, Mendon, Hopedale, Medway, Grafton, Northbridge, Uxbridge, Franklin, Douglas, and Framingham MA.

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Building lasting relationships by helping people move in and out of Metrowest Massachusetts for the last 23 years.

Bill Gassett is a thirty-two year veteran to the real estate industry. He enjoys providing helpful information to buyers, sellers and fellow real estate agents to make sound decisions. His work has been featured on RIS Media, National Association of Realtors, Inman News, Placester, RESAAS, Credit Sesame and others.

Comment balloon 49 commentsBill Gassett • March 27 2009 06:55AM



At a former place of employment, we used an ozone generator, and it did a good job of removing the odor of smoking from the office.  (No one actually smoked in the office, but clients would come in who reeked of tobacco.)  It worked.

Mike in Tucson

Posted by Mike Jones, Mike Jones NMLS 223495 (SUNSTREET MORTGAGE, LLC (BK-0907366, NMLS 145171) ) over 10 years ago

Bill - Odors comes up frequently, especially for those houses that are currently on the market.  Once they are vacant, the plug-ins, the Febreeze, the airing out only can do so much so this blog post is a great recommendation and potential solution ! 

Posted by The Somers Team, Real People. Real Dreams. Real Estate. (The Somers Team at RE/MAX Access) over 10 years ago

Mike & Chris - In my experience an ozone generator has always worked for removing odors. I was surprised to read some of the findings on the EPA site that kind of said the opposite.

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Bill-this is a great source of info...we use them especially after a hurricane..flood or bad odors.  Nothing turns people off more than a bad smell.  We have one..we have cats and as cute as they are..I can't believe those odors that come from those cute little creatures!  

Posted by Midori Miller, Online Marketing For Real Estate Professionals (Talk 2 Midori, LLC) over 10 years ago

Bill - This is great information for the buyers and sellers alike, especially linking to the EPA site for another view.

Posted by Petra Norris, Realtor, Lakeland FL Homes for Sale (Lakeland Real Estate Group, Inc.) over 10 years ago

Erica & Midori - It is good to know that there are others that have experienced the fact that using ozone does remove all kids of odors especially pets.

Petra - Thanks. I wanted to share that there are other view points on the use of ozone.

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Bill, I have an Ozone machine and have used on rental properties to get odors out and they worked so well I was sold!  What a great idea to write about that we are all up against at some time or another.

Posted by Kelly Young, Colorado Springs Real Estate ~ 719-226-0126 (The Platinum Group Realtors) over 10 years ago


There is probably nothing worse than trying to sell a home that is less than a bed of roses.  We are in total agreement on this point.  Ozone or not, sometimes being brutally honest is the best cure.  Hey we read your comment on Sheldon's re-blog of our lunch.  We too would absolutely love to lunch with you one day.



Posted by Robert and Lisa Hammerstein -201-315-8618, Bergen County NJ Real Estate (Keller Williams Valley Realty) over 10 years ago

Bill - Thanks for the information. I've never heard of a ozone machine. I will investigate.  My theory is if you can smell it can't sell it.

Posted by Claude Cross, Charlotte NC Homes For Sale (Homes By Cross, Inc. ) over 10 years ago

I have never heard of that option to remove odors before Bill, thanks for bringing it to my attention.  I thought the only way to get rid of the kitty pee smell was to apply KILZ on the subfloor otherwise it can come back even with new carpet. Would someone rent one just like a carpet cleaner?

Posted by Patricia Beck, Colorado Springs Realty (RE/MAX Properties, Inc., GRI, CDPE) over 10 years ago

Hi Bill, Thanks for posting this information about the ozone machine.  I used to see it advertised on tv but haven't heard much about it lately.  There is a listing (not mine) I would like to show buyers but the odor of stale cigarette smoke is overwhelming.

Posted by Shirley Parks, Broker, 210-414-0966, San Antonio TX Real Estate (Sands Realty 210-414-0966) over 10 years ago

Patricia - You are right about the smell coming back if it has penetrated the sub-floor. You can rent an ozone machine or there are professionals that work with ozone machines as well.

Kelly, Lisa, Claude, Shirley - Thanks for your comments about ozone machines. In my experience these devices do work quite well for removing odors in a home.

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Bill, We have started hearing more and more about this so I will bookmark for the future. It got kind of creepy at dead people and formaldehyde LOL Do you know the approximate cost? Is it based on square footage?

Posted by Barb Szabo, CRS, E-pro Realtor, Cleveland Ohio Homes (RE/MAX Trinity Brecksville Ohio) over 10 years ago

Bill ~  Great information about the ozone machine! I used one once  for a listing I had and it worked really well on removing the odor. Always good to have information to pass along to our clients who are interested in selling and need a little help getting their home ready to list! Thank you!

Posted by Terrie Leighton, Reno Real Estate Agent ~ Selling Homes in Reno (Ferrari-Lund Real Estate ) over 10 years ago

Hi Bill,

I love the effective eradication so much, I sell them!

The industrial strength model is my favorite, for sheer power and speed. Two to three hours for 3000 square feet wipes out pretty much any stink. The unit is about the size of a breadbox.

No pets or human can be present, because the ozone/ionization is so intense, it can kill off the beneficial bacteria in the lungs if you are overly-exposed to the air when the machine is on.

They are perfect for my purposes. As a stager, stink is sometimes a formidable adversary, and I needed a swift and complete odor removal system!

I can see that certain odors from chemicals, such as formaldehyde, might not always be tamed by an ozonator/ionizer. The industrial grade units antibacterialize surfaces to 99%. Most household odors (pets, garbage pales, sick rooms) come from bacteria-based sources. But, I know they also wrangle paint fumes very well, too.

My sister has a fairly graphic blog about their full capabilities, Not For The Faint of Heart.

Thanks for the links, BTW. I always try to educate about both sides of the ozonator/ionizer coin.





Posted by Michelle Molinari, Feature This Real, Estate Staging & Curb Appeal Concepts (FEATURE THIS... Real Estate Staging & Interior Decor) over 10 years ago

Michelle - Thanks for the insight from a stagers perspective on the effective use of an ozone machine. I have never used an industrial size unit but I know that they are very effective. I am going to check out your link ozone when I get a minute.

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Never thought of that! Thanks for the idea. Does it make the air smell like it does after a thunderstorm?

Posted by Linda Greco Rich, ABR, SRES, Harford County Specialist (Exit Preferred Realty) over 10 years ago

Linda - Your welcome. There is a very very small odor that lasts a very short time but I am not sure how to describe it. I guess it would be close to a thunderstorm.

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Bill & Linda -

I'd describe it as slightly clorinated, like a freshly bleached bath towel. The smell dissapates rather quickly, and leaves no odor behind after it airs out. I mean, no odor at all. It completely and permanently neutralized three of those  plug-in-thingy deals, as if I bought "blanks", lol.

It's kinda surreal to walk in a highly odorous location that has clearly smelled nasty for years and years, hit it with the industrial machine for a couple of hours, and never catch another whiff of that old smell again. It's unbelievable, really. But I swear on those babies!



Posted by Michelle Molinari, Feature This Real, Estate Staging & Curb Appeal Concepts (FEATURE THIS... Real Estate Staging & Interior Decor) over 10 years ago

Michelle - I guess I would concur although like you said the ozone smell lasts for such a short period of time I never gave it much thought.

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

I don't like cats or the smells they and their litter boxes create.

Posted by Greg Nino, Houston, Texas (RE/MAX Compass, formerly RE/MAX WHP) over 10 years ago

I heard about it a few years ago then nothing. I might have to try it on some of our homes with stubborn odors. Thanks

Posted by Terry & Bonnie Westbrook, Westbrook Realty - Grand Rapids Forest Hills MI Re (Westbrook Realty Broker-Owner) over 10 years ago

Bill you sure did do your homework for this one!  This is information that is needed quiet often and I found this in depth study most enlightening!  I will bookmark this for future the next time my nose says pee yew I will refer back to your great advice!

Posted by Debbie Hutchins over 10 years ago

Greg - I think cats do create some of the worst odors in a home. You almost always can tell when someone has a cat.

Erica - That sure is a great compliment!

Terry - I would give an ozone machine a try. You will be amazed at how effective it is.

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Debbie - Your clients will love you if you can provide them a remedy for that odor thety just can't get rid off. Trust me these ozone machines do work!

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Bill, I use AirSource and it works so great.  No pet smells, etc.  Does a 3000 sq.ft. home. Here is a site to check it out.

Posted by Pat Laracy Baker, Pat Baker Dream Home Maker (Realty Executives Boston West) over 10 years ago

Hi Pat - I will check out Airsource. Is this a type of ozone machine?

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Thanks for the info on Fresh Air. I believe the costs have come down quite a bit on the ozone machines.

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

My ionizers are all EcoQuest. The one that is preferred for quick odor removal, such as listings require, is the San Air Blaster by EcoQuest. It is industrial grade, and I sell it for $649. And they HAVE come down in price.  I paid $1200 for my first one, and it wasn't even remotely as  strong as the Blaster.




Posted by Michelle Molinari, Feature This Real, Estate Staging & Curb Appeal Concepts (FEATURE THIS... Real Estate Staging & Interior Decor) over 10 years ago

Bill - Odors can make a huge difference to a buyer's impression about a home.  This is a great article to provide to sellers.

Posted by Christine Donovan, Broker/Attorney 714-319-9751 DRE01267479 - Costa M (Donovan Blatt Realty) over 10 years ago

Bill, I had not heard of the Ozone System, but I wish I had heard of it.  A couple of years ago I went to an Open House that the smell was so bad that I almost chocked.  I wish I could have suggested this to that Realtor.

Posted by George Souto, Your Connecticut Mortgage Expert (George Souto NMLS #65149 FHA, CHFA, VA Mortgages) over 10 years ago

Bill - That is fascinating... great research, as usual!  I have one of those teeny ozone devices that plugs in like a night light in my kitties' room near their litterbox.  I guess I should clean it now!  I like the skunk illustration:)

Posted by Wendy Rulnick, "It's Wendy... It's Sold!" (Rulnick Realty, Inc.) over 10 years ago

Bill - I have never heard of this product so thanks so much for sharing.  My home is a pet free zone but I have had listing that could have used it.

Posted by Jennifer Fivelsdal, Mid Hudson Valley real estate connection ( JFIVE Home Realty LLC | 845-758-6842|162 Deer Run Rd Red Hook NY 12571) over 10 years ago

Bill, I hadn't heard of it either.  And thought nothing could help remove the smeil of cat urine in carpets and furntiture.  I think sometimes homeowners don't realize it anymore but potential sellers sure do.  Thank you for the information on these types of products.

Posted by Laura Cerrano, Certified Feng Shui Expert, Speaker & Researcher (Feng Shui Manhattan Long Island) over 10 years ago

Hi Bill, I have a couple of those ozone machines in my tiny little home. Psychologically I think it works!! Hope you have a nice weekend.

Posted by Susie Blackmon, Ocala, Horses, Western Wear, Horse Farms, Marketing over 10 years ago

Hi Bill. I never heard of that piece of equipment but surely would use one if the need arose.

Posted by Tony Orefice, Realtor/Harrisburg NC,Concord NC (Wilkinson ERA/ over 10 years ago

Bill, I've heard of that before, but have never used an ozone machine. Cats leave an awful smell....hard to get rid of. What did you finally do?

BTW? Did you watch that video? Very funny. ;-)


Posted by Mesa, Arizona Real Estate Mesa Arizona Realtor, AzLadyInRed (Homes Arizona Real Estate LLC) over 10 years ago

Michelle - Great information. Thanks for the heads up on that particular ozone model.

Everyone - Thanks for all your comments. If you ever have a problem with a real troublesome odor I would give an ozone generator a try. 

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Hey Bill!  Nasty smells can kill a sale quickly.  Personally, I think buyers find smoke more offensive than pet smells although the pet smells are a close second.  Thanks for the information - I'll pass it on to our friends who are getting ready to list and are comparing ozone machines.


Posted by Bruce & Mary Smith, REALTORS, Savannah Lakes Village McCormick SC (Savannah Lakes Homes) over 10 years ago

Bruce & Mary - I have always hated the smell of smoke offensive myself. I would put pet odors, especially cats a close second as well.

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Bill I remember the days when the fix was to remove the carpet and treat the sub-flooring - expensive, but effective  Karen

Posted by Karen Kruschka, - "My Experience Isn't Expensive - It's PRICELESS" (RE/MAX Executives) over 10 years ago

Karen - The ozone machine will most likely make it unnecessary to remove carpets saving a pretty big expense.

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

I don't favor cats (and cigarette smoke is the worst!) but I have 2 (it's a long story). Since the cats stopped smoking, it's not so bad, but it's even better with an ozone machine that I invested in some time back. BIG difference, for sure! It's really good to be educated on this topic, because it can be a touchy but necessary one to discuss with some sellers. Well done!

Posted by Mara Hawks, Inactive-2012 REALTOR - Homes for Sale Auburn Real Estate, AL (First Realty Auburn ) over 10 years ago

Bill - very comprehensive and balanced article on the subject of ozone as an odor mitigation technique. We used to use negative ion generators for particle removal, but that is a bit expensive for home use.

Posted by Mike Saunders (Lanier Partners) over 10 years ago

I had done some research on ozone machines about 6 months ago when there was a dead animal smell in one of my listings. My research wasn't nearly as comprehensive as yours. I didn't know the machines could be rented. Thanks for the info Bill.

Posted by Jen Bowman, Realtor - Anna Maria Island & Bradenton FL (Keller Williams on the Water) over 10 years ago

Mara - You are correct a cat that smokes is the worst - LOL

Mike - Thanks. Giving both sides or opinions is the right thing to do. I am not really sure why the EPA claims the ozone machines do not work though.

Jen - How did you make out Jen? Did you end up using an ozone machine?

Posted by Bill Gassett, Metrowest Massachusetts Real Estate (RE/MAX Executive Realty) over 10 years ago

Getting rid of pet odor, especially cats, is extremely difficult. I once bought a home that was built in 1898, and the basement floor was cracked and mostly sand. Before I bought it, obviously, cats had used the dirt as a litter box. My own cats started using it as such, too. I called in a company that sprayed a wet substance all over the walls, floor and ceiling. It was supposed to be a safe enzyme that eliminated the odor. I called them back twice to spray again. It worked for about 3 weeks and the smell came back, even though I had locked my cats out of the basement.

Finally, my mother recommended an ozone machine. She had used one when her kitchen caught on fire, and it worked.

sacramento agent

Posted by Elizabeth Weintraub Sacramento Realtor Top 1%, Put 40 years of experience to work for you (RE/MAX Gold) over 10 years ago

Hi Bill - So good to know! I wasn't familiar with ozone odor removal at all:)

Posted by Suzanne Gallegos, Realtor - Salt Lake City, Utah Homes (Equity Real Estate - Advantage) over 10 years ago

This is really interesting.  I had not heard of this before.  I was going to ask if it helped with the smell of smoke, but I see from the comments that it may.  I will definitely look into this more and perhaps suggest it Sellers in the future.  Thanks for the information!

Posted by Susan Jackowski, Lake Norman NC & Hudson Valley NY (Lake Norman NC) over 10 years ago

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