The Science of Ozone (O3)

Table of Contents

Introduction

Ozone is a powerful natural sanitizer, disinfectant and oxidizer which is created by using ordinary tap water.1 This powerful oxidant, has many commercial and industrial applications. More importantly, ozone will effectively destroy bacteria and inactive viruses more rapidly than other disinfectant chemicals.

Ozone is an efficient broad-spectrum antimicrobial agent that is active against bacteria, fungi, viruses, protozoa, and bacterial and fungal spores, by attacking various cell membrane, wall- and cell constituents.2 Aqueous ozone at 1 part per million (ppm) is equivalent to 10 to 4,000 times the concentration of free chlorine, with the right pH, temperature and microorganisms3. After approximately 30 minutes, the ozone decomposes and reverts back into elemental oxygen (i.e., tap water), which can be disposed of down drains without negatively impacting the water systems.

What is Ozone?

The word “ozone” is derived from the Greek word “ozein”4 which means “to smell/scent.” Ozone (O3) consists of three oxygen atoms. Technically, ozone forms naturally in the upper atmosphere where it is a vital gas that protects us from harmful ultraviolet (UV) radiation. Generally, we know it as the ozone layer.

History of Ozone Application and Regulation

1785Idea initiated by Dutch chemist Martinus Van Marum.
1801William Cruickshank observed strange odor during experiments into the electrolysis of water.
1840“Official” discovery of ozone by Christian Friedrich Schönbein.
1857Werner Von Siemens designed an ozone generator, now known as the “Siemens Type” ozone generator.
1865Jacques-Louis Soret discovers the chemical formula for ozone. A prototype ozonometer was built by John Smyth.
1867Schönbein confirmed the ozone formula discovered by Jacques-Louis Soret.
1870C. Lender reports the first instance of ozone being used therapeutically, in Germany.
1879Dr. Kellogg mentions evidence of ozone being used as a disinfectant on his book “DIPHTHERIA: Its Causes, Prevention and Proper Treatment”.
1885“Ozone” by Dr. Charles J. Kenworth, is published by the Florida Medical Association explaining in detail the use of ozone for therapeutic purposes.
1886Meritens realizes ozone’s ability to disinfect polluted water which was later recognized in Europe.
1891Test results from Germany show that ozone is effective against bacteria.
1893Ousbaden, in Holland, get the world’s first water treatment plant using ozone. Ozone is also used for the first time in Algae control.
1896Nikola Tesla patents his first ozone generator.
1897Marius-Paul Otto, First ozone company – “Compagnie Generale de l’Ozone”, in Nice.
1898Thauerkauf and Luth starts the Institute for Oxygen Therapy in Berlin. They test ozone on animals and produce Homozon by bonding ozone to magnesium. A German doctor called Dr. Benedict Lust,  the originator and founder of Naturopathy, starts practicing in New York, and wrote many articles and books on ozone.
1900The Tesla Ozone company, “Tesla Ozone Co.”  is established and starts selling ozone generators to doctors for medical use.
1902Description of the success of using ozonated water in anaemia, cancer, diabetes, influenza, morphine poisoning, canker sores, strychnine poisoning and whooping cough treatments in “A Dictionary of Practical Materia Medica” by J. H. Clarke (London). Siemens and Halske  established the first full scale water treatment plant with ozone in German
1903Niagara Falls, USA, get the first U.S. drinking water installation ozone treated.
1906France commissions its first municipal ozone plant for drinking water.
1909Ozone employed for preservation of meat in Germany.
1911Dr. Noble Eberhart, the head of the Department of Physiologic Therapeutics at Loyola University, publishes “A Working Manual of High Frequency Currents”. Eberhart uses ozone to treat tuberculosis, anaemia, chlorosis, tinnitus, whooping cough, asthma, bronchitis, hay fever, insomnia, pneumonia, diabetes, gout and syphilis.
1914During the World War I (1914-1918) ozone was used to treat wounds, trench foot, gangrene and the effects of poison gas.
1915Dr. Albert Wolff uses ozone to treat colon cancer, cervical cancer and decubitis ulcers, in Berlin.
191649 ozone installations are in use throughout Europe (26 of which in France).
1920Dr. Charles Neiswanger, President of the Chicago Hospital College of Medicine, publishes “Electro Therapeutical Practice.” where the chapter 32 was entitled “Ozone as a Therapeutic Agent.”
1929“Ozone and Its Therapeutic Action” is published in the US describing how to treat 114 different diseases successfully with ozone. The authors were the heads of all the leading American hospitals.
1932Ozone was used in dentistry by Dr Edwin A. Fisch, a Swiss dentist.
1933Research was performed on the effect of ozone on banana ripening, in Gane.
1934Between 1934-1938 Aubourg and Lacoste,  French physicians, use ozone insufflation.
1936Ozone used to depurate shellfish in France.
1939Ozone found to prevent the growth of yeast and mold during the storage of fruits.
1940Aqueous ozone first used to sanitize US Naval Academy pool.
1942Ozone used in egg-storage rooms and in cheese-storage facilities in the USA.
1948Dr. William Turska begins using an ozone generator of his own design, in Oregon.
1951Dr. Turska writes the article “Oxidation”, he pioneers the injection of ozone into the portal vein, thereby reaching the liver.
1953Dr. Hans Wolff, a German doctor, uses ozone in his practice,  wrote the book “Medical Ozone” and trained many doctors in ozone therapy.
1957Ozone implemented for oxidation of iron and manganese in German drinking water.
1964Spontaneous flocculation in ozone contact chambers leads to France constructing an ozone plant to enhance particulate removal.
1965Ozone employed for color control of surface water in Ireland and the UK. Ozone used to oxidize micropollutants such as phenolic compounds and several pesticides in Switzerland.
1970Ozone exploited for algae control in France.
1973IOA (International Ozone Association) was formed to provide the ozone industry with a central database of ideas, technical documents, and communication.
1975FDA approved ozone as good manufacturing practice.5 
1976EPA (Environmental Protection Agency) approves the use of ozone as an antimicrobial oxidant in the US.
1979Dr. George Freibott treated the first AIDS patient with ozone.
1980Dr. Horst Kief reported AIDS as successfully treated with ozone.
1982The FDA (Food and Drug Administration), in the US, grants GRAS (Generally Recognised As Safe) status for ozone use in bottled water, as requested by the IBWA (International Bottled Water Association).
1984The Olympics officially begins using ozone to sanitize pool water.
1987600 MGD (million gallons per day) ozonation plant comes on line in Los Angeles after seven years of pilot testing.
1990Cubans make successfully treatments with ozone to glaucoma, conjunctivitis and retinitis pigmentosa.
1992The Russians reveal surprising results for their techniques in treating burn victims with ozone bubbled in brine.
1995FDA GRAS approval for ozone disinfection of bottled water renewed.
1996Approval in Australia and Japan for use of ozone for food.
1997Expert panel convened by the Electric Power Research Institute (EPRI) affirms ozone as GRAS for direct contact with foods. FDA does not object to this GRAS affirmation.
1998The US EPA (Environmental Protection Agency), in conjunction with the Safe Drinking Water Act of 1991, confirms that ozone is effective in removing hazardous pathogens and chlorine resistant Cryptosporidium from water.
2000A Food Additive Petition (FAP) filed by the EPRI requests FDA approval of ozone for direct contact with foods.
2001Ozone is approved by the FDA as a secondary direct food additive, antimicrobial agent.
2004FDA issues industrial guidance and recommendations to processors of apple juice or cider on the use of ozone for pathogen reduction purposes.
2010ISCO3 Madrid Declaration on Ozone Therapy.

What is Ozone Formed (Naturally)?

It is naturally formed when oxygen (O2) is exposed to sunlight or exposed to high voltages of electricity. Both natural methods break up oxygen molecules to form ozone. Ozone has been known as an accompaniment to electrical storms.6 When lightning strikes the falling water molecules create a small amount of ozone in which wind carries it down to ground level. This natural ozone phenomenon is why there is a fresh, clean smell and the ground appears “extra” clean, particularly following after a thunderstorm, which signifies freshly generated ozone in the atmosphere.

What is Ozone Formed (Artificially)?

Ozone can be produced artificially through corona discharge or ultraviolet exposure. There are several less commercially mainstream methods of making ozone, including electrolysis, radiochemical and reaction of elemental phosphorus with water.

Ozone generators artificially “manufacture” man-made ozone. It creates O3 in much the same way as the sun does. The generator chamber is filled with oxygen (or dried air) which then passes between electrodes (corona discharge method) under a nominal applied voltage and converts some of the oxygen into ozone. As oxygen molecules pass through the electrical field, they are split apart, forming active atomic oxygen radicals that combine with oxygen molecules to produce ozone.7 The UV method production is similar to the photochemical production which occurs in the stratosphere, in which oxygen atoms react with oxygen molecules to form ozone.

Ozone is Safe

Because of residual compounds and reaction byproducts, chemical sanitizing agents have come under scrutiny. In 100+ years of continuous ozone use in thousands of municipal water treatment facilities worldwide, no case of fatality has yet been attributed to ozone. Unfortunately, the safety record of chlorine is not as positive. For example, chlorination byproducts such as trihalomethanes and chloramine compounds are potentially carcinogenic.8 Ozone reaction products from oxidation of organic compounds have not been reported to have adverse health consequences.9 Ozone is also considered as an alternative to chlorine to prevent the formation of halogenated organic compounds.

Aqueous ozone has a triple zero rating by the National Fire Association (NFPA). Under the NFPA exposure to aqueous ozone under fire conditions would offer no hazard beyond that of ordinary combustible materials; aqueous ozone will not burn; and aqueous ozone is normally stable, even under fire exposure conditions, and are not reactive with water. As such, aqueous ozone is safe to handle which means while recommended when cleaning, PPE is not required.

How is Aqueous Ozone Concentration Measured?

In general sanitization procedures, aqueous ozone has a higher oxidation reduction potential (ORP)10 than chlorine used in aqueous solutions. This means that in order to ensure the effectiveness of ozone application, detection technology that works well at the limit of approved concentrations for cleaning and sanitization operations should be used. Ozone is measured electronically, spectromically or via wet chemistry. Measuring electrically or amperometrically, is accomplished with either bare electrodes or through a membrane, such as ORP, conductivity, dissolved ozone (DO), and hydrogen-ion concentration (pH) meters.

Why use Ozone: A Powerful Disinfectant

Ozone is considered a replacement for chemicals (i.e., chlorine) in the antimicrobial sanitization of water, food and food processing surfaces and equipment. Ozone can clean and sanitize both products and direct product contact surfaces continually. When effectively used ozone can keep a location clean and sanitized for less money than current modalities. In practical use, ozone attacks organic compounds indiscriminately, leaving no residual components when decomposition is complete. This means that ozone is a potent oxidizing agent that readily inactivates microorganisms in aqueous solutions.11

Ozone is a very efficient broad-spectrum antimicrobial agent that is active against bacteria, fungi, viruses, protozoa, and bacterial and fungal spores, by attacking various cell membrane, wall- and cell constituents.12 Ozone destroys a bacteria cell, leaving only oxygen, which effectively deodorizes and sanitizes. This on contact process destroys bacteria, dangerous microorganisms, fungi, allergens, and other odor causing agents.13 After approximately ~30 minutes, the ozone reverts back into tap water, which can be disposed of down drains without negatively impacting the water systems or water table.

When oxygen is subjected to high voltage discharge, some of the oxygen molecules disassociate and the freed oxygen atoms then combine with existing oxygen molecules to form ozone. The third oxygen atom in the ozone molecule is loosely bound to the other two atoms and turns ozone into an extremely strong oxidizing agent. In many respects, ozone can be considered a more powerful green alternative to chlorine and other cleaning chemicals.

While in its time limited ozonated state, it becomes one the most efficient and natural sanitizing solutions, which inactivates 99.99%+ of viruses, bacteria and other harmful contaminants. For example, ozone is much stronger and acts more quickly than chlorine, meaning the contact time necessary to sanitize is lessened. Chlorine is generally used at concentrations of 100 to 200 parts per million (ppm) while aqueous ozone is used at only 2 to 3 ppm. Chlorine leaves a detectable chemical residue on the product and is prohibited from use or on imports into many countries. Ozone leaves no chemical residue and permits organic certification. When its effectiveness dissipates, it simply reverts to pure clean oxygen (i.e., tap water).

Ozone Effective For Decontamination

  • Ozone has been used routinely for washing and storage of fruits and vegetables.14
  • Aqueous ozone has been applied to fresh-cut vegetables for sanitation purposes, reducing microbial populations and extending shelf life.15
  • The treatment of apples with ozone resulted in lower weight loss and spoilage.16
  • Increased shelf life of apples and oranges following ozone treatment has been attributed to the oxidation of ethylene.
  • Fungal deterioration of blackberries and grapes was decreased by ozonation of the fruits.17
  • Ozone-containing water was found to reduce bacterial content in shredded lettuce, blackberries, grapes, black pepper, broccoli, carrots and tomatoes.18
  • Microbial studies typically show a reduction of total counts and significant reductions in spoilage and potentially pathogenic species most commonly associated with fruit and vegetable products.19
  • Effects of ozone treatment on the microflora of dried figs resulted in significant reductions in total bacteria, coliform and yeast/mold counts.20
  • Washing of fruits and vegetables was also reported to degrade pesticide residues.21

Traditional chemical cleaning methods are becoming less effective to kill bacteria as it becomes immune to chemicals over time. This clinically tested ”transformation” method is highly-effective. Ozone is recognized as safe and effective when applied properly, and compliant with FDA, USDA, OSHA, NSF/ANSI Standard 50 and UL lab standards. The FDA, USDA, and EPA have approved ozone as an antimicrobial agent.

Ozone Is Approved By The Food And Administration (FDA)

In 1982, the U.S. Food and Drug Administration (FDA) recognized ozone as GRAS for disinfection of bottled water and later recognized it again as a sanitizing agent for bottled water treatment lines under a similar GRAS petition.22 EPRI, a team comprised of export food scientists, concluded in June 1997, “[t]he available information supports the safety of ozone when used as a food disinfectant or sanitizer, and further that the available information supports a GRAS classification of ozone as a disinfectant or sanitizer for foods when used at levels and by methods of application consistent with good manufacturing practices.”23

In 2001, the FDA formally approved the use of ozone as an Antimicrobial Agent for the Treatment, Storage and Processing of Foods in Gas and Aqueous Phases and recognized as a secondary direct food additives permitted in food for human consumption.24

Ozone Is Approved By The USDA National Organic Program (NOP)

The U.S. Department of Agriculture (USDA) National Organic Program (NOP) added ozone to the substances allowed as ingredients in or on processed products labeled as “organic” or “made with organic.”25

Ozone Is Approved By The Department Of Agriculture’s Food Safety And Inspection Service (USDA/FSIS)

In 2001, the U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA/FSIS) approved the use of ozone in contact with meats and poultry, from raw product up to fresh cooked and products just prior to packaging.26

Ozone Is Approved By The Occupational Safety And Health Administration (OSHA)

Occupational Safety and Health Administration (OSHA) controls exposure limits of gaseous ozone to employees in a workplace. OSHA regulates that gaseous ozone levels in ambient air not exceed 0.1 parts per million (PPM) for an 8-hour exposure time.27 Aqueous ozone is not subject to the same parameters as gaseous ozone.

Ozone Device Is Approved By The Environmental Protection Agency (EPA)

In 1976, ozone generators were recognized by the EPA as antimicrobial producing devices.

Ozone National Sanitation Foundation (NSF) Studies Studies Produce 99.9999% Success

The NSF conducted studies according to EPA-established AOAC Official Methods 961.02 & 960.09, Germicidal Spray Products as Disinfectants, and Germicidal & Detergent Sanitizing Action of Disinfectants test procedures (aqueous ozone 1.5-2.0 mg/L) which resulted in 99.9999 of various bacteria and viruses (e.g., Salmonella choleraesuis, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Trichophyton mentagrophyte, Listeria monocytogenes, among others).

Does Ozone Eradicate Viruses?

Most viruses fall into either a non-enveloped or enveloped category. Enveloped viruses are easier to destroy since they are usually more sensitive to physio-chemical challenges. Non-enveloped viruses such as Hepatitis A are harder to destroy.

Studies show that aqueous ozone is highly effective in to inactivate non-enveloped and enveloped viruses.28 Ozone was effective against bacteriophage f2,29 enveloped viral species (including vesicular stomatitis viral species, influenza A virus (WSN strain), infectious bovine rhinotracheitis virus) and nonenveloped viruses (including polio type I and infectious canine hepatitis virus).30 It was determined that hepatitis A virus was inactivated in 5 seconds with 0.4 ppm ozone dose.31

Coronaviruses are classified as enveloped viruses. Like other coronaviruses, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (i.e., the virus that causes COVID-19) is an enveloped virus with an outer lipid envelope, which makes it more susceptible to disinfectants compared to nonenveloped viruses such as rotavirus, norovirus, and poliovirus.32 Ozone has been proven to inactivate “stronger” non-enveloped viruses than enveloped viruses. Ozone destroys these viruses by breaking through the outer seal (outer shell) of the virus penetrating its core. Ozone can also damage the seal in a process called oxidation. Since ozone inactivates the more powerful non-enveloped viruses, it is anticipated that exposing sufficient ozone doses should have the same effect on enveloped viruses and result in it being 99.99% damaged or destroyed.

eClean’s patent pending technology have independently been validated by University of California, Los Angeles (UCLA) Geffen School of Medicine33 and the University of Tennessee-Knoxville (UT) Research Facility34 through rigorous and undisputable lab testing to eradicate Hepatitis A, B and C more effectively and faster than any other process, including chlorinated bleach while complying with all EPA standards. While testing is ongoing, since ozone inactivates the more powerful non-enveloped viruses, it is anticipated that exposing sufficient ozone doses should have the same effect on enveloped viruses and result in 99.99% effectiveness.

Watch our discussion with Dr. Omai Gardner, Director of Clinical Microbiology, UCLA Health, on ozone’s impact on Coronavirus:

COVID-19

How Does Eclean Technologies Create Ozone?

eClean Technologies’ products utilize electrical fields (i.e., corona discharge method) through our patent-pending ozone generator technology to “manufacture” man-made aqueous ozone. (PCT/US19/15288; PCT/US19/51088)

Eclean Technologies’ Products Meet Regulatory Compliance Standards

eClean Technologies’ products meet the highest health, safety, and environmental regulations. Our products clean and sanitize, while eliminating harsh chemical exposure and comply with the EPA and other regulatory standards. We are registered with the EPA and NSF.

eClean Technologies’ products are currently being utilized by the municipalities in the cleaning and eradication of human waste and other existing bacteria on the streets, sidewalks and other surfaces. The levels achieved are equal to or better than previous used approaches (i.e., chlorine bleach and other harsh chemicals).

Our proprietary technology is changing the way residential, commercial, and public spaces are sanitized for increased health and safety by eliminating the use of harsh chemicals and improving the cleanliness while effectively eradicating bacteria and viruses. Our systems reduce cleaning time, have been proven to be safer, and ultimately are a more efficient all-natural sanitizer. By using our products, residential, municipalities, and businesses have experienced a reduction in expenses associated with the high cost of chemicals and storage and are protecting the environment.

 

 

 

 

 

 

 

 

References

1For use as a food-contact sanitizer on hard, non-porous surfaces.

2Hirneisen, K.A.; Markland, S.M.; Kniel, K.E. 2011. Ozone inactivation of norovirus surrogates on fresh produce. Journal of Food Protection, Vol. 74, No. 5, 2011, Pages 836–839 (https://pubmed.ncbi.nlm.nih.gov/21549058/).

3Morris, J.C. In: Disinfection: Water and Wastewater. J.D. Johnson, Ed. (Ann Arbor, MI: Ann Arbor Science Publishers, Inc. 1975); Ozone has been shown to be effective in inactivating a range of bacteria. Ozone oxidizes lipids present inthe cell membrane of the bacteria, intracellular enzymes, as well as the bacterial genome. Guzel-Seydim, Z. B., Greene, A. K., & Seydim, A. C. (2004). Use of ozone in the food industry, 37, 453–460 (https://doi.org/10.1016/j.lwt.2003.10.014).

4Aelteste Nachricht über Ozon und seine Benennung. Ann. Phys. Chem., 1854, 91, 625-627.

5Ozone has been employed successfully for applications including surface decontamination to extend the shelf life of cheeses and fresh produce, decontamination of packaging materials, disinfection of process water and sanitization of processing equipment and food storage areas, among other things. Mahapatra, A.; Muthukumarappan, K.; Julson, J. 2005. Applications of Ozone, Bacteriocins and Irradiation in Food Processing: A Review. Critical reviews in food science and nutrition 45: 447-61 (https://pubmed.ncbi.nlm.nih.gov/16183567/).

6Rubin, M.B. Technion-Israel Institute of Technology. The History of Ozone. The Schönbein period, 1839–1868. Bull. Hist. Chem. 2001, 26, 40–56.

7B. Langlais, D. A. Reckhow, D. R. Brink, Ozone in Water Treatment: Applicationand Engineering, CRC, Boca Raton 1991 (https://www.academia.edu/2215170/Ozone_in_water_treatment_application_and_engineering)

8Pascual, A., Llorca, I. and Canut, A. (2007) Use of ozone in food industries for reducing the environmental impact of cleaning and disinfection activities, Trends in Food Science and Technology, 18: S29–S35.

9Wu, J.G., Luan, T.G., Lan, C.Y., Lo, W.H. and Chan, G.Y.S. (2007) Removal of residual pesticides on vegetables using ozonated water, Food Control, 18(5): 466–72.

10Oxidation Reduction Potential (ORP) is a method to measure oxidation in water. ORP is a common measurement of water quality (i.e., cleanliness) in a wide variety of water treatment applications. In essence, the higher the ORP level reading (i.e., “dirtier”) the more ability the water has to destroy foreign contaminants such as microbes or carbon based contaminants. A high positiveORP is desired in for example, sewage treatment, swimming pools and spas, because the higher the ORP, the more oxidation will occur, thus killing the bacteria and unwanted pathogens. Zeng, X., Tang, W., Ye, G., Ouyang, T., Tian, L., Ni, Y., & Li, P. (2010). Studies on disinfection mechanism of electrolyzed oxidizing water on E. coli and Staphylococcus aureus. Journal of Food Science, 75(5), M253-M260.

11Broadwater, W.T., Hoehn, R.C. and King, P.H. (1973) Sensitivity of three selected bacterial species to ozone, Applied Microbiology, 26: 391–3.

12Hirneisen, K.A.; Markland, S.M.; Kniel, K.E. 2011. Ozone inactivation of norovirus surrogates on fresh produce. Journal of Food Protection, Vol. 74, No. 5, 2011, Pages 836–839 (https://meridian.allenpress.com/jfp/article/74/5/836/173503/Ozone-Inactivation-of-Norovirus-Surrogates-on).

13Ozone has been shown to be effective in inactivating a range of bacteria. Ozone oxidizes lipids present in the cell membrane of the bacteria, intracellularenzymes, as well as the bacterial genome. Guzel-Seydim, Z. B., Greene, A. K., & Seydim, A. C. (2004). Use of ozone in the food industry, 37, 453–460 (https://doi.org/10.1016/j.lwt.2003.10.014).

14Liangji, X. (1999) Use of ozone to improve the safety of fresh fruits and vegetables, Food Technol, 53: 58–61; Karaca, H. and Velioglu, Y.S. (2007) Ozone applications in fruit and vegetable processing, Food Reviews International, 23(1): 91–106.

15Beltran, D., Selma, M.V., Marin, A. and Gil, M.I. (2005) Ozonated water extends the shelf life of fresh-cut lettuce, Journal of Agricultural and Food Chemistry, 53: 5654–63.

16Achen, M. and Yousef, A.E. (2001) Efficacy of ozone against Escherichia coli O157:H7 on apples, J Food Sci, 66(9): 1380–4.

17Beuchat, L.R. (1992) Surface disinfection of raw produce, Dairy, Food and Environmental Sanitation, 12(1): 6–9.

18Kim, J.G., Yousef, A.E. and Dave, S. (1999b) Application of ozone for enhancing the microbiological safety and quality of foods: a review, Journal of Food Protection, 62(9): 1071–87; Barth, M.M., Zhou, C., Mercier, J. and Payne, F.A. (1995) Ozone storage effect on anthocyanin content and fungal growth in blackberries, J Food Sci, 60(6): 1286–8; Zhao, J. and Cranston, P.M. (1995) Microbial decontamination of black pepper by ozone and the effect of the treatment on volatile oil constituents of the spice, J Sci Food Agric, 68(1): 11–18; Sarig, P., Zahavi, T., Zutkhi, Y., Yannai, S., Lisker, N. and BenArie, R. (1996) Ozone for control of post-harvest decay of table grapes caused by Rhizopus stolonifer, Physiol Mol Plant Pathol, 48(6): 403–15.

19Selma, M.V., Beltran, D., Allende, A., Chacon-Vera, E. and Gil, M.I. (2007) Elimination by ozone of Shigella sonnei in shredded lettuce and water, Food Microbiology, 24(5): 492–9.

20Oztekin, S., Zorlugenc, B. and Zorlugenc, F.K. (2006) Effects of ozone treatment on microflora of dried figs, J Food Eng, 75(3): 396–9.

21Wu, J.G., Luan, T.G., Lan, C.Y., Lo, W.H. and Chan, G.Y.S. (2007) Removal of residual pesticides on vegetables using ozonated water, Food Control, 18(5): 466–72.

22Federal Register 47(215):50209-50210. 1982. (https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=184.1563)

23REF: EPRI. Technical Report-i 08026, Vols. 1, 2, 3: (https://www.epri.com/#/pages/product/1005962/?lang=en-US)

24Secondary direct food additives permitted in food for human consumption. Federal Register 66(123):33829-33830. 2001 (https://www.govinfo.gov/content/pkg/FR-2001-06-26/html/01-15963.htm); see also, 21 CFR 173.368, FSIS Directive 7120.1 (https://www.fsis.usda.gov/wps/portal/fsis/topics/regulations/directives/7000-series/safe-suitable-ingredients-related-document);https://www.federalregister.gov/documents/2001/06/26/01-15963/secondary-direct-food-additives-permitted-in-food-for-human-consumption); (https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=173.368);https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=184.1563).

25National Organic Program: USDA Organic Regulations (https://www.federalregister.gov/documents/2017/03/21/2017-05480/national-organic-program-usda-organic-regulations)

26USDA FSIS. Letter from Robert C. Post (FSIS, Washington, DC) to Mark D. Dopp (American Meat Institute, Arlington, VA). Dec. 21, 2001; FSIS Safe and Suitage Ingredients used in the Production of Meat, Poultry, and Egg Products (https://www.fsis.usda.gov/wps/wcm/connect/bab10e09-aefa-483b-8be8-809a1f051d4c/7120.1.pdf?MOD=AJPERES)

27OSHA Standard Numbers 1910.1000, 29CFR for Air Contaminants (https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1000); OSHA Standard Numbers 1910.1200, 29CFR for Hazard Communication (https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1200)

28(https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3816691/);(https://www.noai.org/ozone-kills-coronavirus)(scientific studies prove ozone gas can destroy the SARS coronavirus); Enveloped viruses are easier to destroy since they are usually more sensitive to physio-chemical challenges; Ozone inactivates enveloped and non-enveloped viruses (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3816691/).

29Kim, C.K., Gentile, D.M. and Sproul, O.J. (1980) Mechanism of ozone inactivation of bacteriophage f2, Appl Environ Micro, 39: 210–18 (https://aem.asm.org/content/aem/39/1/210.full.pdf).

30Bolton, D.C., Zee, Y.C. and Osebold, J.W. (1982) The biological effects of ozone on representative member of five groups of animal viruses, Environmental Research, 27: 476–84; Akey, D.H. and Walton, T.E. (1985) Liquid-phase study of ozone inactivation of Venezuelan Equine encephalomyelitis virus, Appl Environ Micro, 50(4): 882–6; Roy, D., Englebrecht, R.S. and Chian, E.S.K. (1982) Comparative inactivation of six enteroviruses by ozone, J American Water Works Association, 74: 660–4.

31Hall, R.M. and Sobsey, M.D. (1993) Inactivation of hepatitis A virus and MS2 by ozone and ozone –hydrogen peroxide in buffered water, Water Sci Technol, 27: 371–8 (https://cfpub.epa.gov/si/si_public_record_Report.cfm?Lab=NRMRL&dirEntryId=129106).

32https://www.who.int/emergencies/diseases/novel-coronavirus-2019/technical-guidance/naming-the-coronavirus-disease-(covid-2019)-and-the-virus-that-causes-it;https://www.who.int/docs/default-source/coronaviruse/situation-reports/20200514-covid-19-sitrep-115.pdf?sfvrsn=3fce8d3c_6; Rutala, W.A., Weber, D.J., 2019. Best practices for disinfection of noncritical environmental surfaces and equipment in health care facilities: A bundle approach. Am J InfectControl 47, A96–A105. (https://doi.org/10.1016/j.ajic.2019.01.014, accessed 6 May 2020)

33https://secureservercdn.net/198.71.233.129/s8l.81c.myftpupload.com/wp-content/uploads/2020/08/eClean-Hemarajata-GarnerPoint-of-Use-Ozone-Water-Sterility-Testing-UCLA.pdf

34https://secureservercdn.net/198.71.233.129/s8l.81c.myftpupload.com/wp-content/uploads/2020/08/eClean-DSouza-Inactivation-of-Hepatitis-A-Virus-by-a-Portable-Ozone-Device-UTennessee-1-24-2019.pdf