During the 1970s, only a handful of drycleaning establishments offered odor removal service to their customers. In the past two decades, however, more and more cleaners have diversified their operations by providing odor removal service to insurance adjusters and contractors who do fire restoration work. It has proved to be one of the better diversifications for a drycleaning business. The capital investment for this service is very small. The most efficient way to conduct this service is by using ozone.
This Bulletin should serve as a guideline for those drycleaners who want to expand their service into the area of odor removal by ozone.
OZONE
Ozone is formed naturally during a thunderstorm. Usually, there is a pungent odor noticeable in the air following such storms. This phenomenon occurs because of the natural oxidation of oxygen in the air by the electrical charge of the thunder; thus, splitting an oxygen molecule (O2) into two free atoms. These two atoms then combine with an oxygen molecule that has not been split, to form ozone (O3). Ozone generators are designed to pass dry air through a high frequency electrical field, resulting in the formation of ozone.
The important difference between ozone and oxygen is that ozone is much more chemically reactive than oxygen. Ozone is one of the most powerful, efficient, and economical oxidizing agents known. When ozone comes in contact with odors, oxidation reoccurs, resulting in the elimination of the odors and the release of oxygen. Commercially, ozone has many uses, including use in water treatment plants, the food industry, hotel and motels, animal hospitals, and in any other industry where removal of odor is desirable, or disinfection is required. In the drycleaning industry, ozone treatment is used mostly in fire damage restoration of textiles.
HAZARDS OF OZONE
With the beneficial properties of ozone, however, come hazards. Ozone is highly toxic even when exposure is at a low one part per million (ppm) level. Symptoms include headache, dry throat, irritation of the respiratory passages, and burning of the eyes. As mandated by OSHA, the maximum allowable exposure for an eight-hour period is 0.1 ppm. Short exposures to higher concentrations of ozone can cause throat irritations and pulmonary edema.
Symptoms of ozone exposure are acute, meaning that there are no chronic effects on healthy people because the body has the ability to repair whatever damage has been incurred. To avoid any employee contact with ozone, the ozone application in the drycleaning plant should be conducted in a tightly sealed area and during the night when the plant is unoccupied. Fortunately, ozone is not a stable gas and breaks down into oxygen in about 30 minutes in the open air.
The other potential problem with the ozone treatment of textiles lies in the fact that the ozone is an oxidizing agent and may contribute to color loss with some dyes. Experiments have suggested that the rate of fading due to ozone depends not only on the chemical makeup of the dye, but also on the fiber in which the dye was absorbed. In general, dyed acetate fabrics that exhibit poor colorfastness may be faded by ozone. Some rubber or rubber-based fabrics or products can be decomposed by ozone.
ODOR REMOVAL FROM TEXTILES
Objectionable odor has many origins: smoke, ammonia fumes, skunk and animal odors, mildew, and floods. Smoke odor is composed primarily of water, carbon dioxide, sulfuric and nitric acids, carbon, and other materials that have not been completely combusted. The solid particles of smoke are composed of unburned carbon materials, often referred to as soot.
The removal of smoke and other odors from textiles poses a difficult task for the consumer to achieve alone. The development of ozone generators has enabled drycleaners to play an active role in aiding the consumer with deodorizing textiles.
Ozone generators are available in many different sizes. A typical generator used in an odor removal service would be 24 inches in width, nine inches in height, and 22 inches in depth. This size generator is recommended to be used for an enclosed area of 1,700 cubic feet. Room size will vary with the dimensions of the generator since each different-sized unit will generate enough ozone for a particular area. A sealable room is mandatory for operation because it aids in obtaining maximum ozone efficiency as well as maximum safety to the employees. Some plants have used an office or spare room as the exposure area.
The machine is ready for use when plugged into an electrical outlet and placed outside the exposure room. The generator is located outside the room to ensure that a constant natural airflow is being passed through the machine rather than reusing the same oxygen contained in the room. This is important because the rate and efficiency of the generator is affected by variables such as air flow and air pressure.
Ozone is heavier than air and should be piped in at the top of the room through a vacuum-sized hose connected to the generator. Fans should be used to circulate the ozone thoroughly within the enclosed area.
Garments should be hung on racks with open buttons and zippers and be placed a minimum of three inches apart to ensure the proper flow of ozone. Treatment time varies with the type of odor problem. Twelve hours of ozone exposure has shown the best overall results.
Once the unit is turned off, it takes approximately 30 minutes for the ozone to convert back to oxygen, after the vent to the atmosphere has been opened. The exhaust fan must be run before anyone enters the room.
Odors can also be trapped in upholstery fabrics. Entire pieces of furniture can be placed in the exposure room for the purpose of deodorization. Mattresses and draperies may also be placed in the room with enough area to let the ozone circulate properly to penetrate the fabrics and remove the odors. It is advantageous to the plant to provide a large door opening to the exposure room so that items of this size can be easily transported.
DRYCLEAN BEFORE OR AFTER
The most frequent question asked by drycleaners before the organic odor or fire damage restoration begins is when the actual drycleaning of the article should be done.
Currently, there are two schools of thought as to whether to ozone treat before or after drycleaning. Advocates of drycleaning before deodorizing claim a greater efficiency of the whole operation by removing excessive soot, mud, and moisture before deodorizing. The effectiveness of the ozone treatment, they claim, is therefore increased by better penetration of ozone into the clean garments. Also, the whole operation is much faster, so the customers are inconvenienced for a shorter period of time. In addition, the damage to fabrics can be minimized by removing traces of acids contained in the soot.
On the opposing side are the proponents of drycleaning after ozone treatment. This group includes the majority of drycleaners who use ozone treatment, and manufacturers of ozone generators. This group believes, according to their experience, that perc tends to “lock in” smoke and organic odors, making removal more difficult. However, if the items to be deodorized are damp, they should be airdried before being treated. This, obviously, will prolong the stay of odor/fire damaged items in drycleaning plants.
So, what is the drycleaning plant manager supposed to do? We suggest following the recommendations of ozone generator manufacturers. They have the experience gained not only with drycleaners, but with other industries where their generators are in use. Additionally, the correct size of the ozone generator to be used in the treatment area should be determined by the manufacturer. The knowledge and experience of those plants that are successfully conducting this service should be sought out.
PROMOTION AND PRICING
There is a great need for smoke odor removal service, as well as flood odor removal. Make the availability of this service known to your target audience. Insurance adjusters are the best source of prospective business for this service.
Also, there are companies that specialize in fire and other natural disaster restoration. They will usually subcontract the work of restoring textiles since they lack the equipment and expertise in this trade.
Ozone generators are priced according to the unit size. The price for a typical-sized unit for the odor removal service starts at approximately $700. The unit expense plus the cost of preparing a treatment room are the initial expenditures needed to begin this service. The main operating expense is the cost of power required to run the generator. Maintenance and upkeep of the unit are minimal.
Ozone generators can also be rented out to homes and businesses for the purpose of deodorizing textiles such as upholstery fabrics and carpets. Ozone has proved to be the best agent for removal of animal urine, mildew, and food odors that have contaminated drapes, carpets, and other household textiles.
A listing of ozone generator manufacturers and any information regarding ozone can be obtained by contacting the International Ozone Association – Pan American Group Branch, 31 Strawberry Hill Avenue, Stamford, Connecticut, 06902 or phone 203-348-3542.
This article is from DLI’s TOI673(1998).
