Written by Purofirst
Modified by Ozone Solutions
Ozone (O3), or enriched oxygen, is a powerful oxidizing gas that has been in use since the early 1800's. Ozone is sometimes referred to as "triatomic oxygen" since it contains three atoms of oxygen rather than two.
Ozone occurs quite readily in nature, most often as a result of lightning strikes that occur during thunderstorms. That "fresh, clean, spring-like rain" smell that we notice after a storm most often results from nature's creation of ozone. We are probably most familiar with ozone from reading about the "ozone layer" that circles the planet above the earth's atmosphere. Here, the ozone is created by the sun's ultraviolet rays and then serves to protect us from the ultraviolet radiation. Ozone is produced commercially by the use of ultraviolet light and corona discharge.
In relation to the property and casualty restoration industry, ozone gas generation is most utilized to remove odors in clothing caused by bacteria and smoke. In this case, an ozone room is used where all odorous clothing is hung on racks and exposed to ozone gas for 24-48 hours, depending on odor severity. The ozone generator is left outside of the room and a short connecting hose allows the ozone to flow into the room. Ozone is slightly heavier than air and will only stratify in very calm environments. The diffusivity of ozone allows it to spread readily throughout a room. It is advisable to place a small circulating fan in the room to help the gas to dissipate and penetrate well.
Although ozone is very powerful, it is very unstable and begins to decompose instantly. Its half life ranges from a few seconds to several hours. When ozone comes in contact with organic compounds or bacteria, the extra atom of oxygen destroys the contaminant by oxidation. Ozone decomposes to oxygen after being used so no harmful by products result.
Ozone will neutralize virtually all organic odors, specifically those that contain carbon as their base element. This will include all the bacteria and fungus groups as well as smoke, decay, and cooking odors. Ozone is not as effective on inorganic odors like ammonia, phosphates, nitrates, sulfates, chlorides, etc.
Ozone is a toxic gas. However, it can be used safely when deployed by specialized generators under proper considerations. The odor of ozone is detectable by most people at a level of 0.003 - 0.015 ppm and becomes intolerable to most people at 0.15 ppm. The general consensus is that when you can smell ozone gas, it's time to evacuate the area of life forms. Ozone use is regulated by OSHA, Occupational Safety and Health Agency, and it has stipulated that the safe allowable level or residual ozone is 0.1 ppm as a weighted average for an 8-hour day. Over exposure to ozone affects our respiratory system. Symptoms such as watery eyes, coughing, heavy chest and a stuffy nose will indicate that the gas is reaching high levels.
The benefits of using ozone for restoration work are fantastic. Smoke odor molecules that infiltrate all porous surfaces can be permanently removed by ozone gas. Only ozone will work on the most stubborn of all odor molecules, that being protein. Odors associated with dead bodies, and other forms of decay, like freezer failure have long resisted normal chemical deodorizing attempts. Ozone again has the potency to neutralize even these contaminants.
One of the most positive features about ozone is that it performs its work, and then reverts back to normal oxygen within 15 to 30 minutes. However, other safeguards must be observed besides evacuation. Due to its oxidizing nature, ozone attacks and degrades natural latex rubber, thus a laminate like silica should be applied to car and freezer door moldings. Ozone also breaks down, and thus oxidizes faster in the presence of moisture. Even high relative humidity can increase its action. Hydrogen Peroxide, a mild bleach, forms when ozone is exposed to sufficient moisture, so certain textiles should be removed.
Last Updated: July 29, 2014