Ultraviolet light bulbs deliver ultraviolet rays at very short wavelengths that are able to disinfect by killing microorganisms. These lamps can help eradicate harmful bacteria and are used for a variety of things, namely in the purification of food, water and air. Because germicidal light bulbs are intended to rid an area of microorganisms, it is essential that the bulbs have regularly scheduled cleaning and are replaced annually to guarantee efficiency.