A simplified approach to the assessment of photobiological safety of LED sources

The radiation from a light source could have many desired effect, but, as all forms of energy, it modifies the material it reaches. Limits are defined by standards to protect human skin eye and retina also against radiation intended for general lighting service. A brief description of the approach identified by the standard is here reported. It requires pretty sophisticated instrument to measure the involved quantities. This work shows the possibility of using instruments usually present in a photometric laboratory, like illuminance meter and radiometers, to approach the issue identified in the standards, at least in some simpler situations, as in the case of LED based light sources. The assured uncertainties are worst than the ones obtainable by following the acknowledged track, but they are small enough to allow to associate the light source with a worst case risk group.