There is no standard for measuring the intensity of odors, such as decibels for sound and lumens for light.
Odor control is not always very successful because perception is very subjective.
The first step in controlling odor should always be the removal of its source. If this is not possible, chemical control should be employed.
Sometimes, use of a masking agent is not advisable because it does not mitigate the health effects of the odor, such as hydrogen sulfide, which results from the bacterial breakdown of organic matter.
The following is a list of odor control methods and procedures that cleaning and restoration technicians can use to improve their odor removal skills.
Cleaning and scrubbing
Water-based detergent cleaning can remove water-soluble malodors and, to some extent, non-water-soluble malodors.
All surfaces, though, should be able to tolerate water-based cleaning.
Airing out the contents
Sometimes simply airing out the contents, especially in sunlight, can dissipate some odors. The major treatments are thermal oxidation (incineration), adsorption, absorption with chemical oxidation and biological oxidation
Common inorganic agents, such as sodium hypochlorite, hydrogen peroxide, potassium permanganate and ozone can readily oxidize most of the usual odor compounds.
In general, the cheapest of these is sodium hypochlorite. Industrially hydrogen peroxide has been used for years to deodorize, disinfect and neutralize hazardous pollutants.
Ozone is a very powerful oxidizing agent it is produced in-situ. Ozone in water decomposes to oxygen and hydroxyl radicals, each of which has a higher oxidation potential than either ozone or chlorine.
While sterilization kills all microorganisms, more practical sanitation is obtained through the use of chemicals labeled as sanitizers or germicides.
Most odor causing compounds are organic in nature, and granulated activated carbon (GAC) is very effective on organic odors.
One drawback is the fouling of carbon with solid or liquid particles. However, a large number of other materials can be used as well.
The odorous molecule removal by soil is attributed to physical and chemical interactions between these molecules and the soil itself.
Microorganisms occurring naturally in many soils can destroy odors. Some of these bacteria and fungi (bugs) have been commercially isolated and selectively adapted for destruction of urine-based odors.
The disadvantage is that the substrate has to be kept moist and warm for the bacterium to be effective on odor and that, unfortunately, is the right condition for mold growth.
These are proprietary formulations of essential oils. The essential oils form a thin charged film around each droplet.
Odorous molecules, attracted to the film, attach to the droplets where they are captured and neutralized by the essential oils.
Cyclodextrins are carbohydrate derived-materials derived obtained by starch fermentation.
Cyclodextrins can reduce malodors on textile surfaces like carpet and upholstery. They trap or encapsulate the odor molecules in the fibers, thereby neutralizing the odor.
Aziz Ullah, Ph.D., MBA, is president of Fabpro Manufacturing, a leading formulator of carpet and upholstery cleaning products. He is a member of the American Chemical Society, senior member of the American Association of Textile Chemists and Colorists and a member of The Textile Institute (UK). He can be reached at www.Fabpro.com.