The most commonly employed type of UV light for germicidal applications is a low pressure mercury-vapor arc lamp, emitting around 254 nm. The lamp produces light via an electric arc through vaporized mercury. While safety tests are being carried out, consider the following:
- Mercury vapor lamps must contain a feature that prevents ultraviolet radiation from escaping. Even with these methods, some UV radiation can still pass through the outer bulb of the lamp. This accelerates the aging process of some plastics, leaving them significantly discolored after only a few years’ service.
- Mercury contamination can occur if a lamp breaks or explodes
- An arc lamp envelope reaches very high temperatures during normal operation and can cause severe burns if touched. Let the lamp cool at least 15 minutes before opening the lamp compartment door.
- When the UV light source is on, do not view it directly regardless of distance.
- Warning signs are necessary to inform about the risk of exposure during use and maintenance. Warning signs should be used where applicable to indicate the presence of potential UVR hazards and to restrict access.
- Avoid touching or scratching the glass section of the lamp. Fingerprints weaken the lamp envelope, and this may lead to lamp explosion.