The rapid increase in the use of LED technology for horticultural lighting applications has also raised discussions regarding the potential human health risks compared to legacy lighting solutions. This is somewhat due to the differences in visual appearance (colour and intensities) of the light in such applications.
At a high enough intensity, any type of light, regardless of the source has the potential to harm the eyes or skin through prolonged thermal exposure or photochemical effects of ultraviolet, blue light &/or infrared emissions. Shorter wavelength, higher energy blue light (400nm and 500nm) can cause retina damage through a combination of photochemical action and high intensity. Higher concentration light sources will provide more direct energy and a higher risk. For example, staring at a clear blue sky (scattered blue light) is a low risk, while looking directly at the sun can begin irreversible damage almost immediately.
Prolonged direct viewing of bright light sources must always be avoided, especially at short distances. In practice, nobody voluntarily spends any significant time looking directly at an intense light source. Common sense and the natural human instinctive aversion reaction (we instinctively shut our eyes or look away) means that prolonged direct exposure of the eye to a potentially damaging light source will be avoided.
Like other lighting technologies,Plant grow lights must be checked for photobiological safety according to EN 62471 – the standard for photobiological safety of lamps and lamp systems. This includes thermal and blue light analysis in the spectral range is 200nm to 3000nm. EN 62471 exposure limit classifications represent conditions under which it is believed most people may be repeatedly exposed without adverse health effects. It should be noted that the classification only indicates potential risk. Depending upon use, the risk may not actually become a real hazard.