Evaluation of the Hazard Caused by Blue Light Emitted by LED Sources

Abstract

The first part of the paper discusses the positive and negative effects of blue light on humans. Then, the paper presents standardized methods of evaluation of potential hazards related to optical radiation emitted by light sources and a diagram of classification of light sources in terms of photobiological hazard. The methods covered in the standard EN 62471 and in the technical report IEC TR 62778:2014 constitute a breakthrough in treating light sources and luminaires as factors that may be significantly harmful to human health in certain conditions. These documents contain explanations and guidelines on evaluating the hazard from blue light emitted by lighting products which mainly emit optical radiation in the visible spectrum. Based on the measurements of photobiological safety based on methods described in the standard EN 62471 we can obtain information about a product and can assign it to one of the four hazard groups. Then, the paper presents the results of blue radiation measurements for the selected types of LED sources, especially those emitting cold colour of light. This is followed by a summary list of blue light hazard for three LED sources - emitting warm, neutral and cold colour of light. Conclusions concerning the safety of use of LED sources were drawn on the basis of analysis of normative documents and results of measurements.