Assessment of ultraviolet radiation emitted by compact fluorescent lamps

Iranians are replacing traditional incandescent lamps with Compact Fluorescent Lamps (CFLs), because they use about a quarter of the power of incandescent lamps and their lifecycle is up to ten times longer. Government encourages public to use CFLs too, for saving energy and reducing carbon dioxide emissions. Small amounts of mercury are used in CFLs, released to the environment if they are broken, but their lower energy consumption and then lower energy production can compensate it. Researchers have shown that CFLs can emit ultraviolet radiation (UVR) at levels that under certain conditions of use can result in exposures higher than ICNIRP limits. This research has been done to make sure that public exposures to UVR, by using CFLs remain within exposure limits defined by Iranian Regulatory Authority in National Standard "Non Ionizing Radiation-Exposure Limits", compatible with ICNIRP limits. Effective irradiance (Eeff) of 50 different models and brands of single and double envelope CFLs with different nominal powers were measured. All measurements were made in a dark room at 30 cm distance from bulbs. For some lower power lamps used in shorter distances, Eeff were defined in 5, 10 and 20 cm distances too. The results show that for all lamps, Eeff is very low in 30 cm distance such that someone may be over exposed if exposure time is at least 16 hours a day (h/d). But at lower distances, 5 or 10 cm, by single envelop CFLs this time may be reduced to 1 h/d. It is concluded that very photosensitive people, or if people use CFLs as desktop or bedside lamps, they are better to use double envelop ones. For distances more than 30 cm and exposure durations less than 16 h/d, exposure levels are lower than standard limits for all ordinary CFLs.