“Shielding of light bulbs helps prevent breakage. Light bulbs that are shielded, coated, or otherwise shatter resistant are necessary to protect exposed food, clean equipment, utensils and linens, and unwrapped single service and single use articles from glass fragments should the bulb break”
Germicidal Ultraviolet lamps must be fabricated from specialized quartz rather than from ordinary glass. This is because ultraviolet radiation at 253.7 nanometers (2537 angstroms) will not pass through most substances. Among the few that can be penetrated are the quartz, from which all UVC lamps are composed, and certain plastics in general. Fuller protective lamp jackets can be extruded to form flexible non-seamed tubing of less than 1mm thickness and I.D. tailored to snugly fit UVC lamps (Slimline, cold cathode and GPH preheat types) at both lamp ends.