LED Safety: Performance of Twelve Glasses Using 9 High-irradiance LEDs

There is rapidly increasing radiant flux performance in the latest solid-state light emitting diodes (LEDs), driven by increasing applications, such as display backlighting, medical services, general illumination, and horticultural lighting. In horticultural applications blue and red LEDs have been widely used for photosynthesis and to explore plant response these two wavebands induce higher photosynthetic capacity than those in the green wavebands. However, it has been reported that blue light has the risk of photochemical injury such as ocular damages. In the International Electrotechnical Commission (IEC) standard 62471:2006– Photobiological safety of lamps and lamp systems, risk groups are classified into several categories based on physiological hazards and the wavelength range including ultraviolet radiation (actinic and near-UV), blue light hazard, and infrared hazard of the lens and cornea. Therefore, with increasing use horticultural LEDs users are at risk of being exposed to ocular and skin hazards as the level of radiation continue to increase. The objective of this work was to investigate transmission performances of different types of glasses under high irradiance level (1,000 W/m²) for use in horticultural working areas. In this study 12 different glasses including welding glasses, safety glasses, polarized glasses, and brand name glasses were examined under 9 different monochromatic high-illuminant LED assemblies. The transmission performances of the glasses were acquired using a spectroradiometer (PS-100; Apogee, Logan, UT, USA). The results of this study will provide specific information for users to select proper safety glasses based on their requirements.