No, Face ID is generally not considered harmful to your health.
The technology behind Face ID uses a laser system to project a pattern of dots onto your face. However, the power output of this system is extremely low, posing no risk of damage to your skin or eyes. In fact, the level of radiation emitted is far below safety limits set by regulatory bodies.
Essentially, the technology relies on infrared light and dot projection, both of which are considered safe for human exposure at the levels used in Face ID. The infrared light is not the same as harmful ultraviolet radiation from the sun.
Therefore, you can use Face ID with confidence, knowing it poses no discernible health risks.