PRB Articles

Fighting Odors With Ozone Technology

An unused industrial yard in Colorado recently found new life as (among other things) an organic-mulch storage site. The mulch was purchased by residents who could use it in gardens as a fertilizer and soil protector.

Sadly, however, a problem developed at the site that city planners had not anticipated. The mulch had an unpleasant odor; during wind storms, the odor became airborne, resulting in complaints from nearby residents and facilities.

One of those complaints came from employees at a recreational park facility. In time, the mulch storage site was removed, but the foul odor remained. The smell had apparently permeated the various structures, and was noticeable to varying degrees as soon as guests entered the park buildings.

In Las Vegas, Nev., a major hotel property had a similar problem--odors caused by unwelcome guest behaviors. Cigarette and cigar odors left behind in rooms designated as nonsmoking were a perennial problem, as were smells from guests cooking in their rooms. Apparently, some guests, especially those traveling with families, brought along hot plates so they could prepare snacks or even entire meals. The odors left behind by such food preparation were still noticeable days later.

Charlie Marinella, a product manager with U.S. Products, a manufacturer of carpet-cleaning and restoration equipment, including odor-eliminating equipment, has dealt with all of these problems and more. “Although eradicating smoke odors in hotels is not uncommon, the mulch problem was a bit unusual,” says Marinella. “But common or not, serious odor problems cannot be ‘fluffed over' with an aerosol fragrance.”

Instead, such situations call for professional odor-eliminating processes and systems, designed to handle difficult or unusual odor problems and to eliminate them permanently. But human know-how is also called for when it comes to understanding odors and selecting the proper tools and equipment to eradicate them.

Search For The Source

In the examples above, the sources of the odor problems were obvious. However, this is not always the case. Before any odor-eradication program can be implemented, the source of the odor must first be removed.

For example, employees and customers at one rural bank branch in Texas noticed an unusual and quite unpleasant odor every time they walked into the facility. Staffers first tried spraying an aerosol fragrance to cover up the odor. This was followed by the installation of fragrance systems that automatically released an air freshener throughout the day.

The odor problem persisted. The bank manager had the building's carpets cleaned using powerful truck-mounted carpet-cleaning equipment, but the odor was still present. Finally, a local contractor was called in to thoroughly search the building from top to bottom and locate the source of the odor. Apparently, hundreds of crickets had managed to find their way into one of the walls of the bank. As they died, their carcasses decomposed, creating a foul odor.

Eliminating the problem, however, would prove to be both costly and problematic, but it had to be done. The first step was to cut open the wall and remove the insect remains. But even after this was completed, the odor problem persisted; unfortunately, the smell had seeped into fabrics, carpets, furniture and other walls. The contractor’s suggestion was to use an electronic-deodorization system, which would safely and quickly remove any remaining odors.

Interestingly, a similar system was used in the park facility and the Las Vegas hotel noted above, with positive results. But what exactly is electronic deodorization?

Electronic Deodorization

Typically, when cleaning professionals, restoration experts, auto detailers or, in this case, building contractors, recommend electronic deodorization, they are referring to the use of ozone-generating or electronic-deodorizing systems. Some controversy has been associated with the systems, which were first introduced during the 1960s. The equipment can create a safety hazard if used improperly. However, this powerful technology--used for nearly 50 years to eradicate stubborn odors--is perfectly safe as long as users follow some simple, common-sense precautions.

In nature, ozone is often produced as a result of electrical charges or lightning. This is one reason for the fresh smell often noticed in the air after a thunderstorm. According to Marinella, ozone-deodorization systems produce ozone molecules that work in a similar manner.

When these molecules encounter odor-producing molecules, such as those created by smoke, food, mulch or even insect carcasses, they oxidize the problem molecules, leaving behind only pure oxygen. "Ozone generators are a restorative treatment," says Marinella. “Once the source of the odor has been removed or eliminated, ozone can restore carpets, drapes, fabrics and interiors damaged by air impurities.”

According to Marinella, ozone technology has been used to eliminate odors caused by:

• Bacteria, mold and mildew

• Smoke caused by fires

• Garbage and odors from fish and pets

• Urine and feces (both animal and human)

• Spores, viruses, fungi and pollen

• Cigarette and other tobacco odors

• Paint fumes

• Building insulation, carpeting and furniture.

Safety And Precautions

Although professionals can be called in to treat a facility with electronic-deodorization systems, the technology also can be used by custodial crews. The systems are actually quite small--about the size of a hand-held vacuum cleaner--and lightweight.

However, no discussion of the use of ozone deodorization is complete without a discussion of safety issues, precautions and tips on equipment selection. High concentrations of ozone can cause respiratory irritation. They can also oxidize latex products, a chemical reaction that can potentially form bleach (hydrogen peroxide), which can then discolor nearby items. Marinella recommends taking the following precautions when using and selecting ozone equipment:

• Clean the area thoroughly. It is often necessary to make use of a combination of cleaning with effective chemical agents along with ozone generators to ensure permanent odor eradication.

• Use systems only in unoccupied areas; remove all plants, animals and other living things from the area to be treated.

• Use common sense when using ozone equipment; take the same types of precautions you would use when working with powerful cleaning agents, such as bleach or ammonia.

• Select only systems that have been tested and approved by United Laboratories (UL) and CSA International.

• Choose equipment with a programmable timer to be turned on and off automatically.

• Select equipment with adjustable ozone output, which can be adjusted to a higher setting for large areas or a lower setting for smaller problems.

Overall, ozone or electronic deodorization has many advantages. Not only does it remove odors, but it is also inexpensive and works relatively quickly. “In some cases, using the system for 30 minutes to an hour or less is all that is required,” says Marinella. “In more challenging situations, several hours may be necessary. But the bottom line is that ozone-generating systems work, which is why they have become the most essential and frequently used tool of the professional deodorizing technician.”

Dawn Shoemaker is a freelance writer for the professional cleaning and building industries. She may be reached at

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