Ozone is an unstable form of oxygen that is created when ionizing energy combines a third molecule to oxygen’s natural two-molecule state; O2 becomes O3. By nature, oxygen is a reactive element that “oxidizes” other elements. Ozone is often called “active oxygen” because it more rapidly oxidizes as it returns to its more stable O2 state. This is why ozone is such a good germicide, fungicide, and deodorizer.
Sterile Bright™ units generate ozone as a consequence of ionizing vacuum UV. Unlike “ozonators” that make ozone using an electrostatic charge, Sterile Bright™ tubes create ozone from ionizing UV energy that radiates several feet away from the unit. Since Sterile-Bright™ fixtures are designed to provide radial 360-degree omnidirectional UV dispersion, ozone distribution does not require a fan. Still, fans or ventilation systems can be used to spread this germicidal gas.
Ozone has been used for sterilization for many decades because it is extremely effective at small concentrations. As little as 0.5 parts per million (ppm) of ozone can deactivate bacteria and viruses. Like most chemical treatments, the higher the concentration, the faster the process. Academic and technical papers suggest germicidal effects can require up to 25ppm for longer periods, however, ozone has the advantage of being an absolute gas, meaning it does not exist as a solid or liquid at room temperature. Thus, when ozone dissipates, its effect is completely gone. This is why ozone has been used instead of liquid and evaporative chemical treatments for sanitizing, deodorizing, and exterminating. For example, many hospitals and medical facilities have used, and continue using formaldehyde vaporization, peracetic acid, and/or chlorhexidine for sanitizing. These chemicals are caustic and toxic; they can cause many adverse reactions in humans and animals as well as damage surfaces and materials.
Ozone has the added advantage of being an irritant to insects and even deadly to bed bugs, dust mites, fleas, and lice. Insects and rodents instinctively flee from small ozone concentrations as little as 1ppm to 3ppm. This means that regular low-level ozone treatments can control pests which, themselves, can be disease carriers. In outdoor applications, ozone bonds to human odor molecules that would attract gnats and mosquitos.
Ozone air purification is debatable science. The Environmental Protection Agency (EPA) has labeled outdoor ozone as a pollutant, while acknowledging that “ozone high” is environmentally necessary, meaning our ozone layer protects us from harmful UV radiation. Ozone is routinely used to sanitize medical devices like ventilators, C-Pap and Bi-Pap sleep devices, and hospital ventilation systems. Ozone is also used to clear ductwork of mold and mildew as well as bacteria. A hot summer day can generate outdoor ozone levels that exceed EPA standards, making the entire effort to regulate ozone questionable. Although the EPA associates ground-level ozone with man-made pollution, natural events like sunlight and lightening create this gas which has been linked to general outdoor microbial reduction.
Ozone is an irritant that can cause burning eyes and air passages. Excessive exposure can be harmful and cause reactions for people with compromised breathing like COPD and asthma. This is why Sterile-Bright™ exposure times are brief and the amount of ozone generated throughout a space does not exceed 1ppm during a customary treatment. Ozone creation declines as distance increases from the Sterile-Bright™ unit. At increments of three feet, ozone generation declines proportionally, depending upon the Sterile-Bright™ power which can range from 250 watts to 2,000 watts. Proper ozone protocols are achieved by following the appropriate exposure times required for each space. It is inevitably up to the operator to determine what levels of ozone are needed for the particular task. For example, if the objective is to discourage insect and rodent infestation in a food preparation or storage environment, higher levels of ozone may be desirable; i.e. kitchens, pantries, and refrigeration lockers.
Ozone is an extraordinarily effective deodorizer. As little as 0.01ppm can freshen air. The Occupational Safety and Health Administration (OSHA) guidelines call for no more than 0.1ppm exposure for 8 hours on a “time-weighted” average. This means that at 0.2ppm the acceptable exposure time is 4 hours and at 0.3ppm, 2 hours. Keep in mind that these are workplace exposure limits, meaning that an individual would be physically working in spaces where atmospheric ozone concentrations were at such levels. Ozone in excess of 5.0ppm is considered dangerous for any form of physical exertion.
All light, including UV, loses intensity with distance. This is in accordance with the “inverse square law.” This is a critical consideration for UV because weaker light requires more exposure time. At some point, the sanitizing process is not feasible. Since each wavelength has a different energy level and propagates differently through air, the UV source must generate the most effective radiation using the least amount of energy and distribute that energy in accordance with the defined application. A stadium poses a different challenge than a hospital room or a vehicle. Spaces with high ceilings like convention centers and exhibition halls are not the same as hotel rooms.