Ultraviolet (UV) light is part of the electromagnetic spectrum emitted by the sun and can also be produced by light bulbs. Installing shortwave UV-C lights in a heating, ventilation and air conditioning (HVAC) unit, specifically in the coil box, is not hazardous. However, the FDA has warned that ozone levels in UV products may be higher than safety recommendations for humans. This can lead to an unpleasant smell after the cycle is complete.
Although the smell is not dangerous, it is still recommended to leave the room during and after the cycle. The level of volatile organic compounds (VOCs) responsible for the residual odor after UV disinfection is negligible and does not pose a threat to human health. When UV-C light hits metals, it has enough energy to expel electrons from many metals, especially aluminum. In conclusion, UV light smell is not dangerous to humans. However, it is still recommended to leave the room during and after the cycle to avoid any potential discomfort caused by the smell.
