A few times each year, research comes to light that stakes a claim that LED-based lighting is inherently dangerous, presumably because of an excess of energy in the blue end of the human visual sensitivity spectrum. The US Department of Energy (DOE) has issued a fact sheet on the topic that refutes any such issues and concludes that white LED light is no more hazardous than light from other sources.
The most recent condemnation of LED lighting came from a researcher in Spain back in May. It turns out, however, that the exposure scenarios reported weren't in any way realistic in terms of how a person would be exposed to LED or any other lighting. We covered the problems with the research in a news item over on our LEDs Magazine website.
The presumed problem with LED lighting is based on the fact that phosphor-converted white LEDs are based on a blue LED with the phosphor producing the white light. Some of the blue photons pass through the phosphor and there is research that documents that excessive blue light can disturb our circadian rhythm and cause other maladies. And the aforementioned study indicated blue light could damage cells in the eye.
The DOE fact sheet, however, explains that all light sources have energy in the blue area of the spectrum. That blue energy is necessary for proper color rendering. Moreover blue light is also proven to be beneficial to alertness when experienced in the morning.
The DOE goes on to say that LED lighting has no more blue energy than lights of the same CCT based on other types of sources. If there were an excess of blue energy in an LED light, it would impact the CCT. Moreover the fact sheet explains that, even with excessively bright lighting, human response mechanisms such as blinking or looking away typically protect the eye from damage.
Of course all types of lighting could potentially damage the eye under extreme scenarios. And the DOE reminded that lighting products should meet photobiological safety standards including CIE S009-2002, ANSI/IES RP27, and IEC/EN 62471. You can find the lighting fact sheet on the SSL Technology Fact sheet section of the DOE's website. For more information on such standards see our series of articles on photobiological safety over on LEDs Magazine.
