What is Ozone?

Ozone (O3), an unstable and colorless gas, is derived from oxygen when it reacts to ultraviolet rays or electrical discharges. Unlike normal O2, ozone molecule contains three oxygen atoms. Interestingly, ozone is produced naturally, most often from electrical discharges during thunderstorms. In fact, the sweet, fresh, spring smell (noticed after the storm) is a result of ozone being created in the atmosphere. Based upon where it’s found, ozone is termed as either a good ozone or bad ozone.

Good Ozone

Good ozone, also known as stratospheric ozone, occurs naturally in the stratosphere. At the stratospheric level, ozone forms a protective shield which stops harmful ultraviolet rays that emanate from the sun, from entering the earth. Widespread use of man-made chemical has resulted in depletion of ozone in the stratosphere and has resulted in "ozone hole." However, a drastic reduction in the use of these ozone-destroying chemical has resulted in the hole being repaired to a great extent.


Bad Ozone

Ground level or tropospheric ozone is formed due to the reaction between Nitric Oxide (NO) and volatile organic compounds (VOC). This takes place when pollutants being emitted by various sources (chemical plants, power plants, cars, refineries, industrial boilers, etc.) chemically react with sunlight. Ground level ozone is very harmful to living beings and forms the main component of “smog." Since ozone can be easily transported by wind, bad ozone is a phenomenon that is present in both urban and rural areas.


Clinical Effects of Ozone Therapy

Various studies have also been conducted on clinical effects of using ozone as a therapeutic aid. Some of these include studies on:

  • Bactericidal, virucidal, fungicidal – Therapeutic ozone known to indirectly activate humoral and cellular immunity mechanism as well as non-specific defense system
  • Anti-inflammatory effect – Aids in oxidization of compounds that have double bonds thereby aiding in regulation of metabolic reactions, development, and sustenance of inflammatory process, as well as resolving pH issues
  • Analgesic effect – Oxidates products acting on nerve endings of damaged tissues and helps in determining intensity of response to pain
  • Detoxification effect – Correcting and activating metabolic processes in renal and hepatic tissues
  • Activating oxygen-dependent processes – ATP synthesis from mitochondrial activation as well as increased levels of dissolved and free blood oxygen
  • Optimizing both pro- and anti-oxidants – Influence of ozone on cellular membranes as well as balancing levels of products aiding in lipid peroxidation
  • Hemostatic effect – High ozone concentration from external use resulting in a hypercoagulation effect. Low concentrations of ozone administered parenterally are characterized by declining coagulative and thrombocytic values.
  • Immunomodulating effect – Aids in adjusting immune response benefitting patients having autoimmune diseases (lupus, rheumatoid arthritis, vitiligo, muscular sclerosis, etc.)

Besides these, other miscellaneous studies on using ozone for treatment of human ailments have also been undertaken.

Effects of Ozone Inhalation

High oxidization characteristics (more than 100 parts per billion) can have severe repercussions on the health of the living beings. It can result in tissue damage in plants as well as respiratory and mucous tissue damage in animals and humans. Thus, at ground level, ozone can transform into a pollutant and a potential health hazard

Human Beings

Aged people, asthmatic patients, children, people doing outdoor work (mainly workers) have the maximum risk of inhaling air that contains ozone. Additionally, people with specific genetic traits and with reduced intake of nutrients such as vitamins E and C also find themselves at a higher risk. Breathing air containing ozone can cause health problems such as coughing, chest pain, airway inflammation and throat irritation. Ozone is also found to worsen diseases like asthma, emphysema, and bronchitis since it harms the lung tissue and reduces lung function.



Higher ozone level can have an impact on sensitive vegetations as well as ecosystems such as parks, wildlife, forests, etc. The impact of ozone on vegetation is felt more during the growing season. Click here to know more about the impact of ozone on ecosystem.

Health Effects, Risk Factors and Health Standards At A Glance

Health Effects

Has increased potential of experiencing:
  • Asthma aggravation
  • Cough and throat irritation
  • Chest pain
  • Decreased lung functions
  • Shortness of breath
  • Lung tissue inflammation
  • Increased susceptibility to respiratory infections

Risk Factors

Factors that can increase risk as well as severity of health effects:
  • Increased ozone air concentration
  • Increased exposure time for certain health effects
  • Activities increasing breathe rate (exercise etc.)
  • Certain pre-existing lung disorders (asthma)

Health Standards

  • The FDA (Food and Drug Administration) restricts O3 output to 0.05 ppm of any indoor medical devices
  • The OSHA (Occupational Safety and Health Administration) necessitates that workers must not be exposed to an average concentration of O3 of greater than 0.10 ppm for eight hours
  • The NIOSH (National Institute for Occupational Safety and Health) has set the upper limit of O3 at 0.10 ppm, which should not be breached
  • National Ambient Air Quality Standard set by EPA recommends average outdoor O3 concentration of 0.08 ppm for an 8-hour period
  • Clean Air Act