A Minneapolis resident turned to a local television help line for assistance with a persistent odor coming from the basement of his home. About six months earlier, rainwater had gotten in through an open window. The problem was not detected for several days until the homeowner noticed an odor emanating from the basement.

At first he thought the odor was coming from the open window’s wooden frame. He had the frame repaired and also had a carpet cleaning company come in to clean up the water damage to the basement carpet.

Afterwards, “the odor was gone and the entire basement actually had a very pleasant fragrance for a couple of weeks,” says the homeowner, “but then the odor gradually returned.”

Believing the odor culprit was most likely the carpet, he had the carpet cleaned once again, and again the odor seemed to disappear, replaced by a pleasant fragrance. But, as before, the odor returned a couple of weeks later.

His questions for the help line: Is the odor coming from the carpet? If so, why was it not removed with the carpet cleanings? And finally, does the carpet need to be replaced?

The answers from the help line were very straightforward, and had the homeowner known some of the answers ahead of time, it would have saved him a lot of money, time, and frustration. Essentially, he was told:

Likely there is mold growing in the carpet and/or padding, and that is what is causing the odor;

When a carpet gets wet, there is about a 48-hour time period in which it can be cleaned and sanitized before mold sets in;
The carpet cleanings only temporarily masked the odor, since the source of the odor was never removed;

The only option now is to remove the carpet and pad from the basement.

 Understanding Odors

Odors coming from carpets in both commercial and residential facilities are more common than many people realize. Because customers will likely turn to a cleaning professional to help remedy such problems, it’s important for the cleaning technician to be an expert on carpet odors, what causes them, and how to remove them.

According to Stephen Hanig, vice president of sales and marketing for U.S. Products and Hydramaster, manufacturers of professional carpet cleaning and restoration equipment, there are four options available to the carpet cleaning professional when dealing with carpet odors:
• Masking the odor;
• Neutralizing the odor;
• Using ozone-generating systems;
• Pairing.

“However, before anything else is done, the source of the odor must be located and removed,” says Hanig. “Sometimes this can be accomplished just by cleaning the carpets with a hot-water extractor, while in other situations, such as when pet urine odors are present, the infested area may need to be treated with special odor-fighting products or the carpet and pad may need to be replaced.” Hanig says that without removing the source of the odor, adding a fragrance to mask the carpet odor is just a temporary fix, as evidenced in the case discussed earlier. However, if hot-water extraction has removed the odor-causing bacteria and contaminants from the carpet, the odor should be gone and masking will add a final touch to increase the customer’s satisfaction.

Neutralizing odors is a bit more involved. It requires the use of chemicals or chemical agents that change odor-causing molecules, essentially neutralizing them so they are no longer a problem. Some of these neutralizers use enzymes to “digest” the odor-causing bacteria, but this tends to be a slow process. Newer neutralizers have been introduced that work very quickly; however, the cleaning professional must be well versed on how to use these products.

Ozone-generating systems—or electronic deodorization systems, as they are sometimes called—are often considered neutralizers. But because they do not involve the use of special chemicals or agents, and work in an entirely different way, they are treated separately here.

These systems have been used successfully and safely to eliminate many types of odors in buildings as well as vehicles and are frequently used in restoration work, such as after fires or natural disasters.

As with other odor-eliminating procedures, first the source of the odor must be eradicated and the carpets cleaned. Then all living things must be removed from the room to be oxidized—plants, pets and people. The cleaning professional then allows the ozone-generating machine to run for 30 minutes to several hours, oxidizing the air and eliminating odors.

The final procedure, pairing, is similar to the use of chemical neutralizers in that cleaning professionals must be very knowledgeable about the use of these products. Pairing agents are chemicals that actually bond with the malodor to create a new, odorless molecule. One such pairing agent is called a counteractant. These combine with the odor-causing molecule and use their chemical properties to change its makeup and form a new, odorless molecule.

The Institute of Inspection, Cleaning and Restoration Certification and other organizations offer entire classes and programs dedicated just to carpet and upholstery odor-control issues and eradication. Because the responsibility for selecting the right odor-removing process or procedure generally falls to the carpet cleaning professional, having up-to-date education and information on the most effective odor-eliminating methods can pay dividends in terms of customer satisfaction. And this can lead to customer referrals, which is the sweet smell of success in the carpet cleaning industry. ❑