Health experts do not recommend the use of ozone air cleaners in homes. Ozone is a known irritant to the lungs and respiratory system.

Federal and state health and safety experts are concerned about the use of ozone because when inhaled alone or mixed with other chemicals, it can damage the lungs. Even relatively small amounts can cause chest pain, coughing, shortness of breath and throat irritation, according to the Environmental Protection Agency. It also can worsen chronic conditions such as asthma and compromise the body’s ability to fight respiratory infections.

Where ozone is located is what determines if it’s more helpful or harmful to humans. In the stratosphere, ozone filters out radiation and is considered beneficial.

However, close to the ground, where people live and breathe, ozone is a pollutant and harmful to the respiratory system. That’s why large cities post ozone alerts on smoggy days, advising people with compromised health to stay indoors.

Ozone can be safely used to purify water and can be used with care in unoccupied dwellings as a way to mitigate certain chemical or biological contaminants. But no person or pet is allowed into those buildings during the treatment and for a specified time afterward.