Are screens and lamps on LED basis suddenly dangerous?


Article by Dr. Ðenan Konjhodžić

The fast growing importance of modern solid-state lighting (SSL) in our daily environment raises important safety concerns such as photobiological safety, in particular blue light hazard (BLH). The current international Standard IEC 62471 contains guidelines for evaluating the photobiological safety of lamps and lamp systems. To ensure reliable evaluation, it places extremely high demands on measuring equipment and procedures.

The standard names two health risks that can be caused by visible light. Intensive light may result in burning of the retina ­–­ a risk that can easily be avoided by normal aversive behavior. However, blue light between 400 and 500 nm causes photochemical damage to the retina (Fig. 1). This so-called blue light hazard may lead to degeneration of the macula and is difficult for normal users to assess. For effective evaluation of blue light hazard the standard specifies a weighting function by which the spectral measurement data must be multiplied. The function covers the wavelength range between 300 and 700 nm with a maximum of 435 to 440 nm.

published in elektronik journal 7/19