Originally Posted by Lawrence
The only way to effectively remove the smell of diesel,smoke damage,"head odour", mold
, etc. is first to remove the cause of the smell so it wont return (obviously) and then run an ozone generator. The ozone (O3) is an unstable gas and the extra oxygen molecule combines with the odour producing molecule and destroys it. The balance of the gas transforms into O2 or oxygen. Ozone generators are used by commercial
establishments which restore upholstery and fabrics damaged by smoke.
The US EPA believes that many manufacturer claims regarding the efficacy and safety
of ozone for indoor pollution and odour control are misleading.
According to the EPA:
* A review of scientific research
shows that, for many of the chemicals commonly found in indoor environments, the reaction process with ozone may take months or years.
* Many of the chemicals with which ozone does readily react, the reaction can form a variety of harmful or irritating by-products.
* Ozone does not remove particles (e.g., dust and pollen) from the air, including the particles that cause most allergies.
* There is evidence to show that at concentrations that do not exceed public health
standards, ozone is not effective at removing many odour-causing chemicals.
* If used at concentrations that do not exceed public health
standards, ozone applied to indoor air does not effectively remove viruses, bacteria, mold, or other biological pollutants.
* An important consideration when using ozone for indoor odour and pollution control is the fact that exposure to ozone above certain concentrations is harmful. The US Occupational Health and Safety
Administration (OHSA) regulates the environment
in places of work.
With respect to ozone they limit worker exposure to ozone at a concentration of 0.10 parts
per million (ppm) to less than 40 hours per week for 50 weeks per year. At concentrations of 0.30 ppm the exposure time drops to 15 minutes! A concentration of 0.30 ppm is 300 parts
ozone per billion parts air by volume, a very small amount indeed.
Ozone has been used effectively as a fumigant for removing mold from houses, but only after the house has been closed and all people removed. After treatment, people are not allowed to return until ozone levels drop to safe levels as prescribed by OSHA.
Industrial and municipal applications for odor
control and removal
of air born pollutants have been practised for many years and probably have inspired the attempts to apply the technology to home use. A classic application is the removal
of hydrogen sulfide (the rotten egg odour) from the air coming from sewage plants or from the sewers themselves. A more recent development has been the use of ozone to treat NOX, an air pollutant that comes from combustion processes such as power plants.
In industrial applications the use of ozone is done in one of two ways. The first is similar to the fumigation process for mold removal in houses. In this approach, an area that has significant odour problems is closed and flooded with an ozone air mixture. The gas is allowed to stand for several hours and then the space is vented to remove the ozone.
Another approach is to take the air from the room and pass it through a scrubber that mixes the air from the room or process with ozone. The treated air is than vented out of the scrubber. This approach is often done were the odor
represent a nuisance to nearby businesses or residences. In some cases provisions are made to remove excess ozone from the vented gas before release. Both wet scrubbers and dry scrubbers are used for this approach.
Ozone can be an effective odour control agent if it is used properly with the necessary precautions taken to prevent exposure of people to unsafe ozone levels in the air. It also requires an understanding of what chemical compounds can be successfully treated with ozone and which ones cannot be treated.