Ozone-producing Indoor Air Cleaners made illegal in the State of California: January 1st, 2009

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.

What is Ozone?

Ozone (O3) is a molecule composed of three atoms of oxygen. Two atoms of oxygen form the basic Oxygen (O2) molecule--the oxygen we breathe that is essential to life. The third oxygen atom can detach from the Ozone molecule, and re-attach to molecules of other substances, thereby altering their chemical composition. It is this ability to react with other substances that forms the basis of manufacturers' claims.

Table 1. Ozone Health Effects and Standards
Heath Effects Risk Factors Health Standards*
  • Potential Risks of experiencing:
  • Decreases in Lung Function
  • Aggravation of Asthma Symptoms
  • Throat irriattion and cough
  • Chest pain/Shortness of breath
  • Inflamation of lung tissue
  • High susceptibility to respiratory infection
  • Factors expected to increase risk and severity of health effects are:
  • Increase in ozone air concentration
  • Greater duration of exposure for some health effects
  • Activities that raise the breathing rate (e.g., exercise)
  • Certain pre-existing lung diseases (e.g., asthma)
(* ppm = parts per million)

Is There Such a Thing as Good Ozone and Bad Ozone?

The phrase "good up high - bad nearby" has been used by the U.S. Environmental Protection Agency to make the distinction between ozone in the upper and lower atmosphere. Ozone in the upper atmosphere; referred to as "stratospheric ozone"; helps filter out damaging ultraviolet radiation from the sun. Though ozone in the stratosphere is protective, ozone in the atmosphere - which is the air we breathe - can be harmful to the respiratory system. Harmful levels of ozone can be produced by the interaction of sunlight with certain chemicals emitted to the environment (e.g., automobile emissions and chemical emissions of industrial plants). These harmful concentrations of ozone in the atmosphere are often accompanied by high concentrations of other pollutants, including nitrogen dioxide, fine particles, and hydrocarbons. Whether pure or mixed with other chemicals, ozone can be harmful to health.

Are Ozone Generators Effective in Controlling Indoor Air Pollution?

Available scientific evidence shows that at concentrations that do not exceed public health standards, ozone has little potential to remove indoor air contaminants.

To view the rest of the article and information that was omitted, please refer to the EPA's public website at www.epa.gov/iaq/pubs/ozonegen.html.