Facts On Ozone Use – Beware!

Is ozone for air cleaning SAFE?

There is significant doubt…

Ozone generators that are sold as air cleaners intentionally produce the gas ‘ozone’. Often the vendors of ozone generators make statements and distribute material that lead the public to believe that these devices are always safe and effective in controlling indoor air pollution. For almost a century, health professionals have refuted these claims.

Some vendors suggest that these devices have been approved by the federal government for use in occupied spaces. To the contrary, NO agency of the federal government has approved these devices for use in occupied spaces. Because of these claims, and because ozone can cause health problems at high concentrations, several federal government agencies have worked in consultation with the U.S. Environmental Protection Agency to produce the public information document linked below.

Manufacturers and vendors of ozone devices often use misleading terms to describe ozone. Terms such as “energized oxygen” or “pure air” suggest that ozone is a healthy kind of oxygen. Ozone is a toxic gas with vastly different chemical and toxicological properties from oxygen. Several federal agencies have established health standards or recommendations to limit human exposure to ozone.”

Can Ozone be Used in Unoccupied Spaces?

Ozone has been extensively used for water purification, but ozone chemistry in water is not the same as ozone chemistry in air. High concentrations of ozone in air, when people are not present, are sometimes used to help decontaminate an unoccupied space from certain chemical or biological contaminants or odors (e.g., fire restoration).

However, little is known about the chemical by-products left behind by these processes (Dunston and Spivak, 1997). While high concentrations of ozone in air may sometimes be appropriate in these circumstances, conditions should be sufficiently controlled to insure that no person or pet becomes exposed. Ozone can adversely affect indoor plants, and damage materials such as rubber, electrical wire coatings and fabrics and art work containing susceptible dyes and pigments (U.S. EPA, 1996a).”

Long term, serious and life-threatening health consequences may result from the use of ozone to address mold spores in the air. The ozone levels that can harm mold spores will also harm the cells in lung cells of people and animals, causing premature aging. Since our lungs are not replaceable! There is no known way to determine how long ozone stays in the air, once it has been fogged. The results from ozone fogging could linger in the air for days, weeks or even a month or more. Everyone living in the space or visiting for an unknown amount of time will be affected. Ozone is only recommended for uninhabitable spaces (like a storage shed).

How can ground-level ozone affect your health? 

The EPA is very blunt on this topic. Read more through the EPA website.

Because of the strongly oxidizing properties of ozone, ozone is a primary irritant, affecting especially the eyes and respiratory systems and can be hazardous at even low concentrations. The Canadian Center for Occupation Safety and Health reports that:

Even very low concentrations of ozone can be harmful to the upper respiratory tract and the lungs. The severity of injury depends on both by the concentration of ozone and the duration of exposure. Severe and permanent lung injury or death could result from even a very short-term exposure to relatively low concentrations.”[65]

Ozone can: 

  • Irritate your respiratory system. When this happens, you may cough, feel irritation or soreness in your throat, or experience chest tightness or pain when taking a deep breath.
  • Reduce lung function. This can make it more difficult for you to breathe as deeply and vigorously as you normally would, especially when exercising. You may notice that breathing starts to feel uncomfortable and that you are taking more rapid and shallow breaths than normal.
  • Inflame and damage cells that line your lungs. Within a few days, the damaged cells are replaced and the old cells are shed—much like the way your skin peels after a sunburn.
  • Make your lungs more susceptible to infection. 
  • Aggravate asthma. When ozone levels are unhealthy, more people with asthma have symptoms that require a doctor’s attention or the use of medication. Ozone makes people more sensitive to allergens—the most common triggers for asthma attacks. Also, asthmatics may be more severely affected by reduced lung function and airway inflammation. People with asthma should have an asthma action plan and follow it carefully when ozone levels are unhealthy.
  • Aggravate other chronic lung diseases such as emphysema and chronic bronchitis.
  • Cause permanent lung damage. Repeated short-term ozone damage to children’s developing lungs may lead to reduced lung function in adulthood. In adults, ozone exposure may accelerate the natural decline in lung function that occurs with age. Many of these effects can lead to increased school or work absences, visits to doctors and emergency rooms, and hospital admissions. Research also indicates that ozone exposure can increase the risk of premature death from heart or lung disease, although more research is needed to understand how ozone may affect the heart and cardiovascular system.

Always research health options and consequences thoroughly! Today’s miracle product is often tomorrow’s toxin. 

Get your questions answered!

Cheryl Ciecko, AIA, ALA, LEED AP, is a licensed architect who helps homeowners and building professionals create safe homes through online education to prevent mold, water damage, and poor indoor air quality. You can find her video masterclasses, online programs, and education subscription options at https://avoidingmold.com/education .

For detailed answers on your specific situation or building project, schedule your appointment for an individual consultation.


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The information contained in this presentation is for educational purposes only and is not intended to diagnose, prescribe, treat, or cure any disease, ailment or injury to the body. It is not medical advice. FDA regulations prohibit the use of medical claims in conjunction with the sale of any product not approved by the FDA. Statements made herein have not been evaluated by the FDA. 

Any products, techniques, and/or personal usage tips referred to are not suggested as a replacement for proper treatment from a licensed health care professional. I am not a licensed health care professional and the decision to use or not to use any of this information is the sole responsibility of the listener and/or reader. Everyone is an individual with different body types, different blood types, different body chemistries, and it is important to remember that what works for one person may not work for another person.