Carpet Odors: How to Diagnose and Eradicate Them

A pricey condominium in a Chicago high-rise was proving to be a very hard sale. The property had been on the market for over six months—a long time even considering the tough real estate market. The real estate agent decided it was time to have a “heart-to-heart” conversation with the frustrated seller, an older gentleman who had lived in the unit for more than a decade.

Did the agent tell his client the price was too high? Actually, both the agent and the seller believed the property was priced rather competitively.

Maybe the property needed some updates, maybe a new kitchen? While the property was certainly not brand new, the kitchen and bathrooms were recently updated, unlikely making this the issue.

Instead, the heart-to-heart the agent had to have with his client focused on something entirely different—the apartment smelled. While the seller tried to refrain from smoking in the condo, there were many days and nights when it was simply too cold to go outside, so he smoked inside. The years of smoke and odor buildup had taken its toll on the condo, especially in the carpets and certain fabrics. Upon entering the property, this was often the first thing visitors and, most importantly, potential buyers, noticed.

This situation is not uncommon. Smoke, typically from cigarettes, is one of the most common carpet odors in both residential and commercial properties. Along with smoke, some of the most frequently encountered odors include:

• Food and beverages that have seeped into the carpet
• Pet urine
• Mold and mildew from water damage
• Off-gassing from chemicals and carpeting, typically newer carpets

When the agent mentioned that he believed the smoke odors most likely emanating from the carpets were contributing to the slow sale, the client indicated he never even noticed the smell and questioned if there even was malodor. This is not uncommon. Long-term occupants of a building or residence where odors are a problem often no longer notice them. Additionally, men, such as the seller discussed here, typically do not notice odors or smells as much as women.  And, older people in general are not as odor conscious as younger people.

Traditional Odor Eradicating Strategies

There are some traditional ways to remove odors from carpets and many continue to prove quite successful, according to Mark Baxter, a veteran of the carpet cleaning industry and an engineer with U.S. Products. “Just so we are all on the same page here, removing odors from carpets and masking odors with a fragrance are two different things,” says Baxter. “While some strategies may include a fragrance, removing offensive odors means attacking the source of the odor so it has been eliminated.”*

Baxter suggests carpet cleaning technicians consider the following:

• Neutralizers:These chemicals, typically used as a pre-spray, are often a combination of solvents, anionic surfactants (compounds that lower the surface tension of carpet fibers, allowing for easier soil and odor removal)and a fragrance. Neutralizers can prove very effective at removing urine and other odors. Using these products, decomposed urine breaks down and is absorbed by the neutralizer, allowing it to be removed from the carpet with hot-water extraction. “When selecting a neutralizer or any chemical designed to remove odors, make sure it will not harm carpet fibers or void [the] carpet manufacturer’s warranty,” adds Baxter. “Select chemicals certified and approved by the Carpet and Rug Institute (CRI) just to be safe.”
• Oxidizers:These chemicals are derived from peroxide compounds and are either pre-sprayed on carpets or mixed in the extractor’s tank. They oxidize and help decompose odor-causing bacteria—very often a source of carpet odors—which are then removed in the extraction process.
• Bio-enzymatic cleaners:Getting more attention in the cleaning and the carpet cleaning industries is the use of bio-enzymatic cleaners to remove odors. In fact, removing odors is one of the primary uses of a bio-enzymatic cleaner, whether used on a carpet, hard surface floor, restroom fixtures or other surfaces. Bio-enzymatic cleaners are made from agricultural products, such as soybeans, corn and coconuts, and formulated with specific enzymes as well as “good” bacteria that allow them to essentially digest surface soils. 

“The effectiveness of all of these products – as with most all cleaning chemicals - invariably improves when using a hot-water extractor,” says Baxter. “Additionally, a machine with relatively high psi is typically better able to loosen and flush out the source of the odor, which can make a big difference in odor removal.”

When Problems Persist

There can be many reasons why a carpet odor problem persists. Possibly, more effort is needed in determining the cause of the odor or its actual source. Using a black light and/or a moisture sensor can help find the source. In some cases, it may not be the carpets at all, but walls, furniture or other surfaces can be contaminated. 

In other cases, the wrong chemicals or combination of chemicals used to eliminate the odor were employed. Or possibly, the machine did not have the extraction power to effectively remove the source of the odors.

In many situations, correcting the problem requires the use of an ozone generator. Ozone, according to the Connecticut Department of Public Health, is a molecule made from three oxygen atoms. The three oxygen atoms form an unstable toxic gas that is highly reactive with other gases in the air, killing airborne odors. Ozone treatment and its beneficial effects should not be confused with “high in the sky ozone,” which shields us from harmful ultraviolet light or “low to the ground ozone,” such as air pollution.

“These systems should be viewed as electronic neutralizers that change odor-causing molecules by causing a chemical reaction,” explains Baxter. “Still, the source of the problem must be found and removed in order for them to be effective, but ozone machines can be very effective at removing any remaining odors, especially smoke odors.”

Hotels often use ozone machines to eliminate smoke odors in guest rooms. They are also frequently used to remove odors in automobiles. However before using an ozone generator, Baxter says, technicians must know a few things about these machines, for instance:

• Remove all people, pets and plants from the area to be cleaned.
• The area should be sealed; if it cannot be sealed, remove all living things from the entire home or facility being cleaned.
• Select systems that have both a timer (to automatically shut the machine off) as well as output adjustments.
• The system should be certified by Underwriters Laboratories (UL) and CSA, both of which test and certify electrical and other products. 

“Finally, if odor is still a problem, you are sure it is coming from the carpet, and a variety of odor-removing strategies have been employed, then you must have a heart-to-heart discussion with the customer,” concludes Baxter. “Most likely, the carpet and padding will have to be discarded and replaced.”

 *Masking odors is typically performed by applying a fragrance to the carpet.  It is used very often to treat odor problems, essentially “drowning out” the odor-causing culprit.  However, in time, the masking ingredients become only a temporary fix at best until the cause of the odor is removed.

Additional Information and Training

The non-profit Institute of Inspection, Cleaning, and Restoration (IICRC) offers education and training programs specifically focused on odor eradication. An IICRC trained technician will likely be familiar with a variety of ways to treat and remove odors from carpet fibers and fabrics.

The Controversy over Ozone

It cannot be denied that there is controversy over the use of ozone machines. But, much of this controversy is the result of consumers using ozone systems designed for home use that can now be purchased online or in retail outlets. These machines may vary in performance and quality. Professional ozone generators can be very effective at odor removal and safe as long as they are used properly by trained technicians.