A protective shield for an ultraviolet-emitting fluorescent lamp comprising a tubular sleeve coaxially surrounding the lamp envelope and formed of a plastic material, such as a fluorocarbon resin of a fluorinated ethylene-propylene, which has a spectral transmittance of at least about 80 percent of the ultraviolet radiation emitted from the lamp over the wavelength range from about 320 to 400 nanometers and substantially maintains such transmittance, along with mechanical integrity, after at least about 1000 hours of lamp operation.