Comparison of the optical radiation safety requirements for light emitting diodes

摘要

For the categorization of possible hazards of products emitting optical radiation two safety standards are provided, separating laser and incoherent broadband sources: the CIE standard CIE S009:2002, "Photobiological Safety of Lamps and Lamp Systems" and the International Laser Safety Standard series IEC 60825 "Safety of Laser Equipment". Both standards require an allocation of products into hazard categories (laser classes or lamp risk groups respectively) based on emission limits. Light-emitting diodes (LEDs), whose characteristics are generally intermediate between the typical characteristics of "lasers and lamps" (in terms of source size, spectral bandwidth and spatial distribution of the emission), are addressed in both standards. Because these two product safety standards were developed by different technical communities for different use and safety considerations the application of both standards to one and the same LED source sometimes appears to lead to quite different appraisals with regard to potential hazard. Therefore, a major objective of CIE TC 6-55 was to provide standardization bodies and manufacturers with a detailed intercomparison by means of LEDs of the two types of standards, to review the scientific fundamentals upon which these are based and to recommend possible changes or clarifications to each standard in order to resolve the situation.