Yes, UV light can generate ozone, but only under certain circumstances and at certain wavelengths. Ozone generation from UV light generally occurs below 240 nm by disrupting the bond of oxygen molecules and causing two separate oxygen atoms. People describe the smell of ozone as an electric spark or a metal, so it is likely that what you smell when you start the oven is ozone gas. UV-C lights can also produce ozone that will accumulate indoors.
When the lights are turned on, the UV-C rays will disperse ozone throughout the house. Most people will detect ozone at concentrations of around 0.01 parts per million (ppm). When the smell of ozone dissipates, its concentration should be below 0.01 ppm. The Food and Drug Administration (FDA) has set a limit of 0.050 ppm for medical devices that produce ozone.
The National Institute for Occupational Safety (NIOSH), the Department of Health and Human Services (DHHS), and the Centers for Disease Control and Prevention (CDC) have created a manual for properly installing UV light, which recommends UVGI (ultraviolet germicidal irradiation) light technology to deactivate airborne TB bacteria. A study conducted by the United States Department of Energy found that photocatalytic oxidation converted more than 95% of the hazardous chemicals in VOCs into harmless carbon dioxide and water molecules. UV lights can significantly reduce the number of microbes in your home's ducts, coils, and airspace. There is an entire industry dedicated to producing “ozone” or charged air purifiers.
Photocatalytic oxidation is achieved when UV rays (from the UV lamp) are combined with a surface coated with TiO2 (titanium dioxide). UVC lamps are unlikely to cause damage, so the best way to avoid UV radiation is to stay away from UVB and UVA lights. In 1935, in a situation similar to that of a chicken egg, UV rays were used to identify the route of airborne infection and, at the same time, to demonstrate the effectiveness of UV rays on airborne pathogens. When UV-C light hits metals, it has enough energy to eject electrons from many metals, particularly aluminum.
Ultraviolet air purifiers use ultraviolet light to reduce mold and mildew, volatile organic compounds, airborne pathogens, flu, germs, bacteria, viruses, and other hazardous air pollutants. There is no doubt that ozone can cause some health problems and many UV systems generate it. However, it is important to note that UV light systems are designed to reduce these health risks by producing ozone at safe levels.