Which type of lamps were designed to emit UVC?

• A. Fluorescent bulbs
• B. Incandescent bulbs
• C. Germicidal lamps
• D. Neon lamps

Answer: (C)

UVC is the portion of ultraviolet light that can inactivate microorganisms by damaging their DNA or RNA. Lamps designed to emit UVC are called germicidal lamps. They usually use a low-pressure mercury-vapor tube that emits primarily around 254 nm, optimized for disinfection, often with protective shielding because UVC can be harmful to skin and eyes.

Other lamp types serve different lighting purposes. Fluorescent bulbs convert electrical energy to visible light via a phosphor coating; they may generate some UV initially, but the phosphor turns it into visible light, so they aren’t designed to emit UVC. Incandescent bulbs produce light by heating a filament and mainly emit visible light with little to no UVC. Neon lamps rely on gas discharge to produce visible glow, not UVC radiation.