Did you ever test the safety of ozone based home air filters? One student's science fair project was featured in Sierra magazine.
Her mother has asthma and used an ozone based home filter. She tested to see if her breathing improved after turning on the machine. Then she asked other people to come to her house, sit in the room with the filter for a period of time. The result was that all participants had more difficulty breathing after sitting in the room with the filtered machine.
See more on indoor ozone here.