Ozone is a colorless gas with a noticeable odor.
When inhaled, it can damage the lungs and irritate the throat. Although ozone is found and is naturally produced in the atmosphere, it is also a main part of air pollution called smog. In the upper layer of the sky, ozone is helpful in protecting us from some of the effects of the sun. Inhaling fairly low amounts of ozone can result in signs and symptoms such as coughing, congestion, wheezing, shortness of breath, and chest pain in otherwise healthy people. People with already existing asthma, bronchitis, heart disease, and emphysema may find their conditions worsen while inhaling ozone.