Ozone Effect on Pathogens

Ozone for Disinfection and Inactivation of Pathogens:

As a biocide, ozone works similarly to chlorine (another oxidant) and is used in a similar manner.  Ozone disinfects by directly oxidizing and destroying the microorganism’s cell wall, causing cellular components to leak outside the cell. This causes protoplasmic destruction of the cell, damaging constituents of the nucleic acids, and breaks the carbon–nitrogen bonds, which leads to depolymerization. During the process, ozone splits into oxygen and an ozone atom, which is lost during the reaction with the microorganism’s cell fluids, O3 -> O2 + (O).

This list is not meant to be a comprehensive list of every pathogen ozone can destroy, but a helpful guide to understand the power of ozone.  Due to the nature of the direct oxidation power of ozone there is no mechanism for pathogens to create an immunity to ozone as with other chemical disinfectants and biocides.

See how ozone kills bacteria through the process of Lysis here.

Find info on ozone reaction with chemical compounds here.


Ozone destroys viruses by diffusing through the protein coat into the nucleic acid core, where it damages viral RNA. At higher concentrations, ozone destroys the virus’ exterior protein shell so that DNA or RNA structures are affected.

VIRUSES SUSCEPTIBLE TO OZONE:Virus destroyed by ozone

  • Adenovirus (type 7a)

  • Coxsackie’s viruses A9, B3 & B5

  • Cryptosporidium

  • Echovirus 1, 5, 12 & 29

  • Encephalomyocarditis

  • Hepatitis A

  • GD V11 Virus

  • Infectious hepatitis

  • Influenza

  • Norovirus

  • Rotavirus

  • Tobacco mosaic

  • Vesicular Stomatitis

  • Legionella pneumophila

  • Poliomyelitis virus 1, 2 & 3



Ozone interferes with bacterial cell metabolism, probably by inhibiting the enzymatic control system. A  sufficient amount of ozone breaks through the cell membrane, destroying the bacteria.

BACTERIA SUSCEPTIBLE TO OZONE:Pathogenic bacteria inactivated with ozone

  • Aeromonas harveyi NC-2,

  • Aeromonas salmonicida NC-1102

  • Bacillus anthracis,

  • Bacillus cereus,

  • Bacillus coagulans,

  • Bacillus globigii,

  • Bacillus licheniformis,

  • Bacillus megatherium sp.,

  • Bacillus paratyphosus,

  • Bacillus prodigiosus,

  • Bacillus subtilis,

  • Bacillus

  • Stearothermophilus

  • Clostridium botulinum,

  • Clostridium sporogenes,

  • Clostridium tetoni

  • Cryptosporidium

  • Coliphage

  • Corynebacterium

  • Diphthriae

  • Eberthella typhosa

  • Endamoeba histolica

  • Escherichia coli

  • Flavorbacterium SP A-3

  • Leptospira canicola

  • Listeria

  • Micrococcus candidus,

  • Micrococcus caseolyticus KM-15,

  • Micrococcus spharaeroides

  • Mycobacterium leprae,

  • Mycobacterium tuberculosis

  • Neisseria catarrhalis

  • Phytomonas tumefaciens

  • Proteus vulgaris

  • Pseudomonas aeruginosa,

  • Pseudomonas fluorscens,

  • Pseudomonas putida

  • Salmonella choleraesuis,

  • Salmonella enteritidis,

  • Salmonella typhimurium,

  • Salmonella typhosa,

  • Salmonella paratyphi

  • Sarcina lutea

  • Seratia marcescens

  • Shigella dysenteriae,

  • Shigella flexnaria,

  • Shigella paradysenteriae

  • Spirllum rubrum

  • Staphylococcus albus,

  • Staphylococcus aureus

  • Streptococcus C,

  • Streptococcus faecalis,

  • Streptococcus hemolyticus,

  • Streptococcus lactis,

  • Streptococcus salivarius,

  • Streptococcus viridans

  • Torula rubra

  • Vibrio alginolyticus & angwillarum,

  • Vibrio clolarae,

  • Vibrio comma

  • Virrio ichthyodermis NC-407,

  • Virrio parahaemolyticus

Fungus and Mold:

It is believed that ozone destroys fungi and mold by diffusing through the fungalwall and into the cytoplasm, disrupting the organelles that direct cell function.

FUNGUS AND MOLD SPORES SUSCEPTIBLE TO OZONE:Mold and fungus destroyed by ozone

  • Aspergillus candidus,

  • Aspergillus flavus,

  • Aspergillus glaucus,

  • Aspergillus niger,

  • Aspergillusterreus,

  • Saitoi and oryzac

  • Botrytis allii

  • Colletotrichum lagenariu

  • Fusarium oxysporum

  • Grotrichum

  • Mucor recomosus A & B, Mucor piriformis

  • Oospora lactis

  • Penicillium cyclopium, P. chrysogenum and citrinum,

  • Penicillium digitatum,

  • Penicilliumglaucum,

  • Penicillium expansum,

  • Penicillium egyptiacum,

  • Penicillium roqueforti

  • Rhizopus nigricans,

  • Rhizopus stolonifer


Fungal Pathogens:

As described above, the mechanism by which ozone kills various fungi is through the destruction of organelles in the cell’s cytoplasm.


  • Alternaria solani

  • Botrytis cinerea

  • Fusarium oxysporum

  • Monilinia fruiticola,

  • Monilinia laxa

  • Pythium ultimum

  • Phytophthora erythroseptica,

  • Phytophthora

  • parasitica

  • Rhizoctonia

  • Solani

  • Rhizopus

  • stolonifera

  • Sclerotium rolfsii

  • Sclerotinia

  • sclerotiorum



The exact mechanism by which ozone kills protozoa has yet to be determined. The following table lists protozoan species susceptible to ozone.

PROTOZOA SUSCEPTIBLE TO OZONE:Protozoa inactivated by ozone

  • Paramecium

  • Nematode eggs

  • All pathogenic and nonpathogenic forms of Protozoa

  • Chlorella vulgaris (algae)



Parasitic cysts are of special concern in drinking water derived from surface water sources because they are unaffected by chlorine. Ozone at proper doses will destroy
cysts listed in the table below.

CYSTS SUSCEPTIBLE TO OZONE:Cysts destroyed by ozone

  • Cryptosporidium parvum

  • Giardia lamblia, Giardia muris




Algae in drinking water supplies release organic chemicals during normal metabolic processes and after they die. These chemicals typically do not cause human illness, but do create problems of taste and odor and the potential for increased formation of trihalomethanes


  • Chlorella vulgaris

  • Thamnidium

  • Trichoderma viride

  • Verticillium albo-atrum,

  • Verticillium dahlia



Similarly to related molds and fungi, various types of yeasts may be destroyed with ozone through the same mechanism.


  • Baker’s yeast

  • Candida albicans

  • Common yeast cake

  • Saccharomyces cerevisiae,

  • Saccharomyces ellipsoideus,

  • Saccharomyces sp.