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. Breathing ozone may also increase the risk of getting certain lung diseases.
People can recover from short-term exposure to low levels of ozone.
However, breathing high levels of ozone or breathing low levels of ozone over a long period of time may have more damaging and longer-lasting effects. If an air cleaning device produces ozone at a level that is effective in killing molds and viruses, then it is also at a level that can be harmful to human beings and pets. Unless you have a likely source for ozone in the indoor setting, AND unless you have some possible signs and symptoms of ozone exposure, testing the indoor air for ozone is not likely to be helpful, informative, or needed. Rather than focusing your attention and finances on testing the air, try to improve air quality by using other fairly low cost options. There are national standards relating to the amount of ozone that certain types of equipment or devices may produce and there are standards for workplace exposure.