LED safety and the evolution of international standards

Oct. 25, 2007
For the purposes of LED safety analysis, newer standards use lamp-based rather than laser-based criteria. However, with continued improvements in LED performance, safety standards for LED are still evolving, according to Neil Haigh and Geoff Archenhold.
As everyone working in the LED industry is aware, LEDs are getting brighter and brighter. People are also aware that many of today’s LEDs are so uncomfortably bright that even a momentary glimpse of the source can leave a strong after-image on the retina that persists for several minutes in many cases.

A strong after-image is never a good thing and yet there seems to be little awareness of the actual eye hazards posed by LEDs: are they safe to view, or not? If so, for how long? Does LED safety need to be formally assessed and measured? If so how should this be done? Furthermore, how should an LED product be labelled for the purposes of eye safety?

These are all important questions, and some answers can be found in the work of national and international optical radiation safety committees in tackling the LED safety issue. Foundation work in LED safety was put in place as long ago as 2001.

Subsequently, however, a sideline debate has dominated matters concerning whether or not an LED is to be treated as either a "lamp" or a "laser" source. With this debate now concluded in favour of a lamp-based safety analysis, 2008 should be the year when clear guidelines are issued to answer all of the above questions.

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This article was published in the September/October 2007 issue of LEDs Magazine.

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