Restoration logo
search
cart
facebook twitter linkedin youtube
  • Sign In
  • Create Account
  • Sign Out
  • My Account
Restoration logo
  • NEWS
  • PRODUCTS
    • New Products & Technologies
    • Submit Your Product
    • Interactive Product Spotlights
  • EDUCATION
    • KnowHow.
    • Podcasts
    • Trade Shows & Expos
    • Training & Certification
    • Webinars
    • Whitepapers
  • TOPICS
    • Water Damage
    • Fire & Smoke Damage
    • Mold
    • Contamination
    • Odor
    • Contents
    • Architecture
    • Catastrophe
    • Cleaning
  • BUSINESS
    • Managing Your Business
    • Insurance/Legal Matters
  • BUYER'S GUIDE
  • VIDEOS
    • Ask Annissa
    • Ask the Expert
    • Ironclad Marketing Minute
    • TradeTalks
    • Video Channel
  • INFOCENTER
    • Mold and Mycotoxins
  • THE EXPERIENCE
    • Conference & Exhibition
    • Convention & Trade Show
    • R&R Special Issue
  • EMAG
    • eMagazine
    • Archive Issues
    • Contact
    • Advertise
  • SIGN UP
Contamination Restoration & Remediation​

Ozone vs. Coronavirus: Ozone’s Efficacy as a Virucidal Disinfectant

By David Hart
ozone corona
April 22, 2020

It’s no secret in the cleaning and disaster restoration industry that ozone is extremely effective at removing odors through molecular oxidation.  Lesser known is its efficacy as a disinfectant, for which it has been used effectively in the medical field for many years. A powerful gas capable of high levels of disinfection, ozone can be very effective at killing pathogenic bacteria and fungi, as well as for inactivating viruses. The focus of this article is the use of ozone as a virucide, with emphasis on the SARS-CoV-2, which, according to the International Committee on Taxonomy,  is the accurate name for what is commonly referred to as the COVID-19 coronavirus, and is how it will be referenced in this article.

What is a virus?

Quoting the National Institute of Health: “A virus is an infectious agent that occupies a place near the boundary between the living and the nonliving. It is a particle much smaller than a bacterial cell, consisting of a small genome of either DNA or RNA surrounded by a protein coat. Viruses enter host cells and hijack the enzymes and materials of the host cells to make more copies of themselves. Viruses cause a wide variety of diseases in plants and animals, including AIDS, measles, smallpox, and polio”, and of course the various strains of coronavirus, including SARS-CoV-2[1] .

They can enter the body through the nose, mouth or breaks in the skin.  Different viruses infect different types of cells based upon the ability of the virus to both recognize the host cell type and successfully enter the cells. Once inside (infection), virus genome is activated to produce the replication proteins necessary to create new virus particles, and the cycle is repeated.  For example, cold and flu viruses will attack cells that line the respiratory or digestive tracts. Norovirus, for example, invades the gastro-intestinal tract. The cells of the lungs and bronchi are targets for SARS-CoV-2.

Viruses can stay active on surfaces for different amounts of time, depending on the virus, the surface type, and the environment.  Cold viruses can remain active on surfaces for up to a week, while flu viruses can survive for about 24 hours, and the SARS-CoV-2 virus remains active for about 72 hours.  It’s during this time that the virus is quietly adherent to surfaces, waiting to be taken up by a passing host, that restorers have their opportunity to intervene.

Let’s set the record straight in regard to the correct language for destroying viruses before we “put ‘em in the ring” with ozone.  Depending on with whom you speak, you’ll hear somebody say they’re “killing the virus”.  Other common terms are deactivating and inactivating.

Which is correct?

As we’ve already discussed, viruses are not living organisms in the traditional sense - they are not made of cells, they cannot reproduce without invading a host cell, they do not respond to environmental stimuli, and they have no metabolism. Because a virus is not “alive” in the first place, it therefore cannot be “killed”.  References to killed virus in the medical literature refer to a technique where virus are chemically or mechanically inactivated so that they can be used in the production of vaccines or used in research without the possibility of causing infection, or in our case, to disinfect a surface or space. It is in this sense that we are using the term “inactivating”, where we are using ozone to chemically treat a virus so that it cannot infect living cells.

coronavirus germ

How does ozone inactivate viruses?

To address this question, I reached out to some of the most knowledgeable doctors on the topic of ozone and viruses in the country.  Dr. Gérard Sunnen is a medical doctor in New York City, specializing in the uses of ozone in the medical field, ranging from cutting-edge ozone therapy to the use of ozone as a disinfectant.  According to Dr. Sunnen. “Ozone has unique disinfectant properties. As a gas, it has a penetration capacity that liquids do not possess. In view of the fact that , SARS-CoV-2, MERS, and previous SARS strains persist on fomites (surfaces) for up to several days, it is suggested that ozone technology be applied to the decontamination of medical and other environments”.

Knowing that something works isn’t enough; let’s look at how ozone works at inactivating viruses.  “Typically, viruses are small, independent particles, built of crystals and macromolecules. Unlike bacteria, they multiply only within the host cell. Ozone destroys viruses by diffusing through the protein coat into the nucleic acid core, resulting in damage of the viral RNA. At higher concentrations, ozone destroys the capsid or exterior protein shell by oxidation” explains Dr. Sunnen.  Further, “most research efforts on ozone's virucidal effects have centered upon ozone's propensity to break apart lipid molecules at sites of multiple bond configuration. Indeed, once the lipid envelope of the virus is fragmented, its DNA or RNA core cannot survive”.

In my quest for further communication with experts in the field, I reached out to a director for the Center for Disease Control (CDC), Dr. Paul Meechan PhD, MPH, RPB, CBSP, SM(NRCM).  I asked him his thoughts on ozone as a virucide, especially in regard to SARS-CoV-2.  He responded, “Will ozone work- you betcha! Ozone is very effective at inactivating viruses, especially enveloped viruses like the SARS-CoV-2. Within seconds, ozone solubilizes the lipid membrane of the virus. Ozone will inactivate SARS-CoV-2, but you have to know what you're doing.

graph

How much ozone is required to be effective?

Log reduction is a mathematical term that is used to express the relative number of living microbes or active viruses that are eliminated by disinfection, and corresponds to inactivating 90% of a target microbe with the microbe count being reduced by a factor of 10. Thus, a 2 Log reduction will see a 99% reduction, or microbe reduction by a factor of 100, and so on. The table below shows the chart of Log reduction.

Log Reduction Reduction Factor Percent Reduced
1 10 90%
2 100 99%
3 1,000 99.9%
4 10,000 99.99%
5 100,000 99.999%
6 1,000,000 99.9999%

An easy way I remember this scale is that the number of nines is equal to the Log reduction number. For example, 1 Log = 90%, 3 Logs = 99.9, 5 Logs = 99.999, etc.

Depending on the virus targeted, concentration and exposure time varies. Considering the structure of SARS-CoV-2, and how like viruses respond to ozone exposure, it is estimated that as little as 1 ppm concentration for a matter of seconds is sufficient to achieve as much as 4 logs disinfection. A good quality ozone generator should have no problem reaching this concentration within a short period of time.

Ozone level output is key; generators are rated by the grams of ozone they generate per hour (g/hr). To test the time required to achieve 1 ppm concentration, we used RamAir’s OzoGen 16g, which has an output of 16 g/hr.  Our laboratory consisted of a 1000 ft.³ space, at 65° F and 14% RH (relative humidity).  The generator achieved .5 ppm in 15 seconds, and 1 ppm in < 2 minutes.  As ozone generators convert ambient oxygen into ozone by way of molecular fission and fusion, the rate of output slows as the concentration elevates, resulting from a continuous depletion of available O2 molecules in the enclosed space. Therefore, peak ozone generation is directly dependent on the power of the ozone generator, as lesser systems would plateau at a lower ozone concentration.  High power ozone generators also have the benefit of achieving effective concentrations more quickly, which allows for greater overall utility and benefit.  

David Hart, alongside a select team of doctors and scientists, is spearheading a rigorous testing program to acquire precise data on ozone’s inactivation of specific strains of pathogenic bacteria, fungi and viruses, in regard to concentration and exposure times.

To Summarize

Ozone, having been proven in the lab and in the field to be an extremely effective virucide and full-spectrum antimicrobial, killing pathogenic bacteria and fungi, offers many benefits over alternative ways of disinfecting.

Because it is a gas, it has a penetration capacity that liquids do not possess.  An ozone generator never needs to be refilled with solutions, and it doesn’t need to be manually operated; simply set the timer and press the button. The machine goes to work turning the oxygen in the ambient air into powerful, oxidizing ozone. You return after the prescribed period of time, and the disinfection is complete.


Thank you to Dr. Gérard Sunnen, Dr. Paul Meechan, and Paul Glidden, PhD for their valuable contributions to this article.

KEYWORDS: COVID-19 disinfection services ozone generator

Share This Story

Looking for a reprint of this article?
From high-res PDFs to custom plaques, order your copy today!

David Hart, Founder and CEO at RamAir International, is a 30-year veteran in the professional cleaning and restoration industry. He is the inventor of the RamAir line of HVAC duct cleaning equipment and the OzoGen 16g high-output ozone generator— industry leading products that are in use in every major city of the United States and 21 foreign countries. Hart also holds a position on the board of forensics remediation for the Restoration Industry Association (RIA). To contact him, visit his website ramair.co.

Recommended Content

JOIN TODAY
To unlock your recommendations.

Already have an account? Sign In

  • mold remediation

    Fighting Mold and Bacteria Damage

    Successful mold remediation can be multidisciplinary,...
    Mold Remediation
    By: Josh Woolen
  • certifications and licenses for restoration professionals

    Certifications and Licenses Every Restoration Company Needs

    Restoration companies need to make sure they have the...
    Restoration Training/Education
    By: Sharon Elzarat
  • a wall covered in moss and fungus

    Zero Tolerance for Toxic Molds: Essential Steps for Successful Remediation

    Understanding the importance of zero tolerance for toxic...
    Mold Remediation
    By: Michael A. Pinto CSP, SMS, CMP, RTPE, FLS, ERS and Kendra Seymour
You must login or register in order to post a comment.

Report Abusive Comment

Manage My Account
  • eNewsletter
  • Online Registration
  • Subscription Customer Service
  • Manage My Preferences

More Videos

Popular Stories

Pop Art Female Superhero Punches a Masked Villain

TPAs vs. Independence: The Restoration Industry’s Own Version of the Cola Wars

RIA Carrier Advocate Mark Springer

Turning the Page: A New Era of Trust and Collaboration in Restoration

Paul Davis Restoration Leadership Team

Justin Graham Expands Paul Davis Restoration’s Reach with Acquisition of Greater Seattle Franchise

Submit Your New Product/Technology to R&R!

Would you like to promote a new restoration, remediation or cleaning product/technology with Restoration & Remediation? Fill out the question below to start your submission:

Events

September 3, 2025

The Experience Convention and Trade Show

The Experience Convention & Trade Show logoJoin us in Las Vegas for The Experience Convention & Trade Show, the leading event for cleaning, restoration, and remediation pros, packed with hands-on demos, expert speakers, and high-impact networking. Happening September 3–5, 2025 at Caesars Forum—this is where the industry comes to learn, connect, and grow!

View All Submit An Event

Poll

Doffing PPE

When you are doffing your PPE, do you sanitize between every step?
View Results Poll Archive

Products

The Cleaning, Restoration, Inspection, and Safety Glossary

The Cleaning, Restoration, Inspection, and Safety Glossary

The Cleaning, Restoration, Inspection, and Safety Glossary.

See More Products
Prepare for CATASTROPHE with R&R!

Related Articles

  • Ozone 101

    Ozone 101: Using Oxygen Molecules for Odor Removal

    See More
  • DeadBodies_FT

    Dead Bodies Can Breathe New Life Into Duct Cleaning: A Case Study

    See More
  • Photo courtesy of RamAir International

    HVAC Meth Decontamination

    See More

Related Products

See More Products
  • CRIS.gif

    The Cleaning, Restoration, Inspection, and Safety Glossary

  • Specialized-Spotting.gif

    Specialized Carpet Spotting

See More Products
×

Stay ahead of the curve with our eNewsletters.

Get the latest industry updates tailored your way.

JOIN TODAY!
  • RESOURCES
    • Advertise
    • Contact Us
    • Directories
    • Store
    • Want More
    • Submit a Press Release
  • SIGN UP TODAY
    • Create Account
    • eNewsletters
    • Customer Service
    • Manage Preferences
  • SERVICES
    • Reprints
    • Marketing Services
    • Market Research
    • List Rental
    • Survey/Respondent Access
  • STAY CONNECTED
    • LinkedIn
    • Facebook
    • YouTube
    • X (Twitter)
  • PRIVACY
    • PRIVACY POLICY
    • TERMS & CONDITIONS
    • DO NOT SELL MY PERSONAL INFORMATION
    • PRIVACY REQUEST
    • ACCESSIBILITY

Copyright ©2025. All Rights Reserved BNP Media.

Design, CMS, Hosting & Web Development :: ePublishing