The weighted irradiance energy or intensity of radiation of the 2.0 or ‘low UV-B’ bulbs and 10.0 or ‘high UV-B’ bulbs was 3.12 mW/m2 and 22.1 mW/m2, respectively, estimated using the erythemal action spectrum of McKinlay and Diffey (1987) used to measure the carcinogenic effectiveness on human skin.