Light emitting diodes (LEDs)Fifty years after their invention, light emitting
diodes (LEDs) are increasingly being used. From an occupational health and
safety perspective, since the rapid progress of LED-technology leads to ever
more powerful LEDs, the question of their photobiological safety arises. Which
directives and standards are to be observed in carrying out the risk assessment?
European Directive 2006/25/EC on artificial optical radiation sets out the
minimum requirements and exposure limit values to protect the eyes and skin of
workers against risks from artificial optical radiation. Measurement methods
are set in EN 62471:2009 "Photobiological safety of lamps and lamp systems".
The standard divides the sources of incoherent optical radiation (such as
incandescent and fluorescent lamps, LEDs, etc.) into four groups: in the Exempt
Group (no photobiological risk) and the Risk Groups 1 to 3 with increasing
Results of the evaluation of different LEDs, predominantly in the visible
spectrum (34 single LEDs with or without lens, three LED torches, five LED
lamps, one LED reflector) show: The LEDs in the visible spectrum exceeded the
emission limit value for photochemical retinal damage and reached Risk Group 2
at most. None of the emission limit values for thermal retinal hazard has been
exceeded. Almost all LEDs which exceeded the limit were white or blue LEDs
(except for one green LED).
During a deliberate long-term close-distance look into a white or blue LED, the
exposure limit value for photochemical retinal hazard can be exceeded in only
10 seconds. The sum of single exposures at certain workplaces (such as the LED
industry, the installation of lighting systems or the theater and stage
lighting) can exceed this time rapidly.
This is but one example of new risks and challenges for workers and employers
because of the evolution of society and the changing world of work. The
Community strategy on health and safety at work 2002-06 called on the European
Agency for Health and Safety at Work to 'set up a risk observatory' and to
'anticipate new and emerging risks'. A first forecasting exercise aiming at
identifying emerging physical risks related to occupational safety and health
(OSH) has been carried out by the European Agency for Safety and Health at
AplusA-online.de - Source: Federal Institute for Occupational Safety and Health (BAuA)