Why Ozone is the Gold Standard for Disinfection of SARS-Contaminated Areas?

A Plausible "Penny" Costing Effective Treatment for Corona Virus

Existing Modalities for air disinfection

One of the most common methods employed it the use of ultraviolet (UV) radiation. When given a long enough exposure to UV radiation (UV-C) kills viruses and bacteria by damaging the DNA/RNA inside the microorganism’s cells. Unfortunately, due to the long dwell time requirements, UV radiation is only able to disinfect air close to the lamps because UV light has limited penetration capacity and the airborne viruses and bacteria don’t get exposed for long enough. Another issue is one of shadows. UV light and typically only treat the top sides of objects in a room being treated. All buildings contains nooks and crannies and three dimensional interfaces where viruses, bacteria, nano-bacteria and spores can hide. In case of a SARS or respiratory type coronavirus contaminated room, UV disinfection alone is not adequate to provide virus-free environment, there are shadowed areas hidden from light and tiny inaccessible spaces where the pathogens can are hiding.

With the recent coronavirus outbreak, well-known air cleaning methods are being touted like the employment of High Efficiency Particulate Air (HEPA) filters. While true that HEPA filters can capture particulate sizes down to 0.3 microns, some bacteria with sizes larger than 0.3 microns are able to be captured by the filter, however viruses, nanobacteria, mycoplasmas and more go sailing right through them like water through cheese cloth. Although HEPA filters are somewhat effective in reducing airborne bacteria, theyare completely ineffective at removing viruses, which are nanometers (10-9 m) in size. Also, in order for air to be filtered or cleaned it must pass through the filter itself. This means that HEPA filters can only filter the air that is close to the return vent of the filter itself. There a multiple flaws in attempting to use HEPA filters for virus elimination and containment principally the tiny size of tviruses themselves and the inefficiencies inherent in HVAC design.These multiple drawbacks make HEPA filters unreliable for removal and disinfection of SARS coronavirus contaminated areas.

Chemical disinfectants can also be used for air and surface disinfection, and are typically fogged, sprayed or wiped onto surfaces. However, these chemical disinfectants pose just as many challenges. In order for most of them to work or to be effective at killing or disinfection they must leave the surfaces wet for up to ten minutes. This is impracticle and is rarely done, infact if it were done the water left behind after the active killing is accomplished becomes potential microbial food if the products are indeed biodegradable. If the products are not biodegradable they are often difficult to degrade or break down, and this results toxic chemical residues being left behind and pose additional risks as they remain hazardous to human health.

In 2002 Scientists at Los Alamos National Laboratory were tasked with developing a protocol for disinfecting aerosolized microbial contamination, specifically anthrax spores. They discovered that there was no one step panacea, but that using the above traditional approaches also left behind contaminated structures due to the hidden three dimensional interfaces that exist in all buildings where the viruses bacteria and spores can hide. Instead the researches put forth the hypotheses that the only way to truly decontaminate a building was to fill it full of ozone gas in what is known as a high concentration ozone shock treatment. Ozone is a well-documented method to kill microorganisms effectively because it is a potent oxidizer. Ozone is widely used to sanitize water and is used in modern wastewater treatment plants and in cities all around the world. Recent studies demonstrate that using ozone to disinfect indicate in experimental results (2,3) that ozone can be as effective in disinfecting air as it is in water. For example, Kowalski et al (2) investigated the bactericidal effects of high ozone concentrations on E. coli and S. aureus and concluded that more than 99.99% death rate was achieved for both species after ozonation.

In addition to it’s immense killing power, it kills germs more than 3,125x faster than chlorine bleach, ozone’s gaseous nature makes it an ideal airborne sanitizer. In fact it was entered into the Federal Register in 2001 as a USDA Organic Label Program approved sanitizer in both it’s aqueous and gaseous forms. As opposed to the limitations UV radiation and HEPA filters which are proven to be ineffective, ozone as a gas is easily able to penetrate into to every nook cranny crevice and hidden cul de sac in the structure, easily sanitizing the entire room effectively. Ozone is unstable, and has an extremely short half life, therefore when the ozone generator is turned off within minutes it is readily converted back to normal oxygen, leaving behind no harmful residues after sanitization is complete.

Ozone has not only been proven to be effective in the laboratory setting it is also has been used effectively in a multitude of real world settings to both sanitize the air and surfaces. Here, we share the efficacy of ozone treatment for SARS type corona virus, the effectiveness of ozone in disinfection of a conference room.

Disinfection capacity of ozone

Ozone (O3) is a highly reactive gas made up of three atoms of oxygen. It is reactive because the gas will easily degrade back to its natural state,or normal stable oxygen (O2). What really does the work when it comes to ozone is the extra free oxygen atoms or free radicals. Free radicals are highly reactive and they can oxidize almost anything (including viruses, bacteria, organic and inorganic compounds) after short periods of contact, which makes ozone an incredibly powerful oxidizing sanitizer or disinfectant.

In fact, ozone is far more powerful and reactive than other common disinfectants such as chlorine and hypochlorite, it kills germ over 3000x faster. Unlike chlorine or hypochlorite ozone doesn’t degrade into other toxic by-products. Due to the possibility formation of carcinogenic by-products such as trihalomethanes (THM) chlorine or hypochlorite are no longer being used in many countries.

In contrast, ozone rapidly degrades into pure oxygen and doesn’t generate similar toxic residue. Because ozone harnesses the power of oxygen and doesn’t generate toxic by-products. Ozone has become one of the dominant water treatment methods in Europe and in the United States of America, due to the lack of toxic byproducts. Ozone for air sanitization is less popular than the in water because ozone is harmful to the lungs to breathe, therefore all air treatments must be done in unoccupied spaces.

Procedure for air disinfection using ozone

In order to test for the effectiveness of ozone in reducing airborne bacteria, a conference room with area about 12m2 was selected for testing. As high levels of ozone are required to kill viruses, bacteria and mold spores, the disinfection process was carried out in an unoccupied space, after people, plants and pets were removed.

In order to reach shock treatment levels a high output ozone generator is needed like the Bioblaster, from www.bestozonegenerator.com The capacity of the chosen ozone generator must have the capacity to generate high ozone levels of at least (2.5 – 5 ppm) inside the treatment area. Depending on the model use circulation fan may need to be placed in the room to ensure through distribution of ozone. After closing all the windows and doors, the ozone generator was turned on with a remote control located outside of the treatment area before beginning the ozonation. Concentration of ozone was monitored using a digital ozone meter (Ecosensor). Different levels of ozone (0.5, 2.5 and 5 ppm) were tested to determine the optimal value for killing as much microorganisms as possible. After turning off the ozone generator, ozone level began to drop as it degraded to normal oxygen.

For safety reasons, no people should enter the room until the level of residual ozone is below 0.02 ppm. In general, ozone concentration drops to below 0.02 ppm in an hour after ozonation, therefore people should wait for at least one - two hours (after turning off the generator) before entering the “shock ozone treated” room.

Figure 1 shows a typical curve (concentration vs. time) during ozonation process. As shown in the figure, the ozone concentrations increase very slowly initially in the first few minutes. The delay in increasing the ozone concentration is due to the consumption of ozone for oxidizing pollutants (including bacteria and viruses) in the initial period. After oxidizing the major pollutants, ozone concentration inside the room rises rapidly up to the desired level. To ensure entire room disinfection, high levels of ozone were maintained for 30 minutes. When the ozone generator was turned off, the ozone concentration dropped gradually as ozone converted back to pure oxygen.

Effectiveness of ozone on reducing airborne bacteria

The total airborne bacteria in the conference room was measured before and after each shock ozone treatment. Measurement was carried out using an Andersen N-6 single-stage sampler with Tryptone Soya Agar (Oxoid) in petri dish. 283L of air was taken for each sampling. The petri dish was incubated at 35oC for 48 hrs before counting. The disinfection efficiency of ozonation at different concentration was tabulated in Table 1.

Table 1. Reduction of Airborne Bacteria after Ozonation

The results of the testing prove that ozone is effective in at reducing and killing the bacteria . At higher ozone levels, the sanitizing effect increased. Over 90% of airborne bacteria could be reduced at 2.5 ppm concentration.

Unlike laboratory experiments conducted by Kowalski et al (1) that removed 99.99% airborne bacteria after high ozone shock treatment, in this experiment the best reduction percentage in our case was around 93% only. The reason for this is thought to be because the conference room was not 100% sealed and the HVAC system introduced new bacteria laden air via the make up air intake on the system. Also doors were opened briefly during each air sampling (for placing a new agar dish on the sampler) and the aforementioned air exchange from outside was unavoidable.


Experimental data shows that ozone is effective in reducing airborne bacteria of unoccupied room. Over 90% of airborne bacteria in this real world experiment were reduced after ozone shock treatments. Viruses are more susceptible to ozone than bacteria because bacteria are protected by a cell wall. Ozone has been demonstrated to easily damage the protein lipid coating on the surface of the virus and it damages the RNA replication mechanism of all viruses. This means it is ideal for the destruction Ozone is a gas, and as a gas can permeate the tiniest hidden place in a room or facility, and with powerful oxidizing power, its disinfection efficiency is superior to UV radiation and unlike HEPA filters it actually works! Since ozone shock treatments are performed in unoccupied rooms only and all the residual ozone breaks down naturally after the treatment, so it is perfectly safe for humans. With the tremendous oxidization power and it’s penetration capacity leaving behind residues after the treatment, ozone is recommended for use in disinfection of SARS-contaminated environments.


1. Gérard V. Sunnen, SARS and Ozone Therapy: Theoretical Considerations, http://www.triroc.com/sunnen/topics/sars.html (2003).
2. W. J. Kowalski, W. P. Bahnfleth, and T. S. Whittam, Ozone Sci. & Eng., 20, 205-221 (1998).
3. T. Masaoka; Y. Kubota, S. Namiuchi, T. Takubo, T. Ueda, H. Shibata, H. Nakamura, J. Yoshitake, T. Yamayoshi, H. Doi, T. Kamiki, Appl. & Environ. Microb., 43, 509-513 (1982).
4.Development of a Practical Method for Using Ozone Gas as a Virus Decontaminating Agent: James B. Hudson , Manju Sharma & Selvarani Vimalanathan (2009)
5. Ozone Disinfection of SARS-Contaiminated Areas Kenneth K. K. LAM

Click on the Links below to Download Hard Science University Whitepapers, and Scholarly Articles which prove the efficacy of ozone!

File type icon File name Description Size Revision Time
Development of a Practical Method for Using Ozone Gas as a Virus Decontaminating Agent
Development of a Practical Method for Using Ozone Gas as a Virus Decontaminating Agent 507k v. 1 Apr 17, 2020, 4:54 PM
The Practical Application of Ozone Gas as an Anti fungal Agent
The Practical Application of Ozone Gas as an Anti-fungal (Anti-mold) Agent 500k v. 1 Apr 17, 2020, 5:09 PM
Ozone Disinfection of SARS-Contaiminated Areas 44.5k v. 1 Apr 17, 2020, 5:09 PM
Protocol for Eradication of Viruses Using positive pressure ozone
Protocol for Eradication of Viruses Using positive pressure ozone 15.3k v. 1 Apr 17, 2020, 5:09 PM
Protocol for Eradication of Viruses Bacteria and Mold Spore on Surfaces of Transportation Vessels
Protocol for Eradication of Viruses Bacteria and Mold Spore on Surfaces of Transportation Vessels 176k v. 1 Apr 17, 2020, 5:09 PM
Safety Data Sheet
SAFETY DATA SHEET for OZONE(Formerly MSDS) 1770k v. 1 June 27, 2018, 5:09 PM
FDA Study 270k v. 1 Jul 7, 2011, 5:09 PM
Fields of ozone applications
Fields of ozone applications 404k v. 1 Jul 7, 2011, 4:58 PM

Here's what some experts say about Ozone!

"The trouble is that one soon gets used to bad air, and bad odors are not apt to be noticed after awhile; but the fact remains that pure air is more wholesome than contaminated air. In our regular daily life, it is almost an impossibility to provide for fresh air. No amount of ventilation, not even an unbearable draft, will be capable of keeping a room or a place in good condition, unless one takes recourse in ventilating with ozonized air. Removal of bad odors by means of air flushing is an absolute impossibility, and yet they should be removed. That is where ozone comes in. The method of purifying the air by ozone has the advantage of being fully reliable, very efficient and inexpensive."

Authority: A. Vosmaer, Ph.D.,
London, England Electrical and Chemical Engineer In
"Ozone, its Manufacture, Properties and Uses"

"Ozone destroys virtually all odors that are present. It does not merely mask them. The destruction of odors is impossible when air is circulated only, or when oxygen is used. This fact has been proven in cold storage warehouses, where all kinds and any food products are stored. Odors are not present regardless how strong they might be, or where they may originate, if only low concentrations of Ozone is used."

- E. W. Reisbeck. M. E.,
Ozone Research Authority,
In "Air Conditioning and Ozone Facts"

"As a deodorant for odors and stenches of organic origin, ozone has long proven effective and we can only confirm this general opinion."

- Dr. Philip Drinker,
School of Public Health, Harvard University

"Ozone destroys organic odors. Ozone is a deodorizer of powerful stenches, such as from garbage incineration and fat rendering. When the odors from chimneys cause public nuisance, Ozone has big commercial usefulness."

- Milton J. Rosenaw, MD,
In "Preventive Medicine and Hygiene"

"The effect of Ozone was thought in the past to be a masking action, but more recently the tendency is to hold that it is purely an oxidizing process. Most odors encountered in ventilation problems result from hydrocarbon compounds suspended in the atmosphere in minute quantities as the result of human or animal respiration and from various organic processes. These hydrocarbons are immediately oxidized upon coming in contact with ozone, the resulting products being water and carbon dioxide, both odorless. This process is effective in completely removing the scent of odors, if the reaction is complete, which requires that the Ozone be in such a manner as to insure its even distribution throughout the air.

- Editorial In "Heating and Ventilation Magazine"

"...In sales, cooler, fresh and sweet air at times would be a distinct selling advantage. OZONE seems to offer this solution, in the meat packing plant. In fact, it is being widely used in cold storage plants to correct the very situation objectionable in the meat packing plant."

- In "Refrigeration and Air Conditioning"

"Unpleasant odors are not masked or covered up, but are literally destroyed. The results in an ordinary room are almost immediate. Where clean, fresh air is desirable, this machine has a definite contribution to make to the Medical World."

- George A. Johnstone, MD,
Medical Director of Behrens Memorial Hospital Glendale, California

"When Ozone comes in contact with dead organic matter, oxidation immediately takes place with destruction of the organic matter. In this, it is powerful in removing odors."

- Dr. J. C. Olson