This article reports on a general method of evaluating exposure to infrared
radiation (IR-A, IR-B, IR-C) from high temperature (T > 1000 degrees C) bl
ack body sources, simply by performing measurements with a luxometric and/o
r near IR detector. The method, which may be applied to any black body sour
ce, uses the universality of the Planck formula for the black body spectrum
, which allows estimation of the radiated power in any wavelength range by
measuring the power radiated in another range. This capability may be very
useful when the range of interest is one in which radiometers are expensive
and difficult to calibrate, as for the IR-B and IR-C ranges, because a mor
e commonly available luxometer can be used instead. The results of measurem
ents and evaluations in two traditional Italian glass factories are reporte
d and compared with the threshold limit value given by the American Confere
nce of Governmental Industrial Hygienists. Intense exposures in the IR-B an
d IR-C ranges has been found for some workers, exceeding the limit by a lar
ge factor. This exposure must be reduced, as it has been shown by epidemiol
ogic studies that there is indeed a correlation between cataractogenesis an
d work with fused glass and metals.