Whilst the potential hazards associated with optical radiation have been long understood, up until recently, a consideration of such has been mainly limited to a number of specific applications using intrinsically harmful lamps, such as those emitting UV employed in tanning lamps and industrial applications, with much resting on the presumption that no hazards were posed in the majority of cases. In the absence of specific product-related standards, these measurements would have been made with reference to exposure limits published by ICNIRP/ ACGIH, following the guidance of ANSI/IESNA RP27.1-3 or CIE S009.

In the meantime, significant developments in particular in LED technology, and their use in a wide range of applications necessitated a particular consideration of how to evaluate the photobiological safety of these peculiar devices.

In the first instance, LEDs were treated as lasers and evaluated according to the laser standard IEC 60825, an unsatisfactory situation which did not reflect the inherent differences between lasers and LEDs. The subsequent re-arrangement of standards has given the required impetus to establish standards for the consideration of the photobiological safety of all broadband sources.

IEC62471:2006

To address the issue of appropriate standards for the evaluation of LEDs, the IEC created a new standard IEC 62471:2006, adopting the text of CIE S009 (now published as a dual-logo document), and removing LEDs from the scope of IEC 60825 for all but communications applications.

IEC62471 gives guidance for evaluating the photobiological safety of electrically-powered lamps and lamps systems emitting optical radiation in the range 200-3000nm and provides exposure limits and a framework for classification.

This standard constitutes a horizontal standard, providing no product-specific safety requirements, safety measures or labelling requirements. In the absence of such, guidance is provided in IEC 62471-2.

EN62471:2008

IEC62471 has been adopted by CENELEC in Europe, due to be placed as a harmonised standard under the terms of the low voltage directive.

It follows that to CE mark a device under the terms of the LVD requires consideration of the optical radiation safety.

It should be noted that the exposure limits adopted in EN62471:2008 are not those of IEC62471:2006, but of the EU Artificial Optical Radiation Directive. At present there exists a sole discrepancy between the two, due to the adoption of current ICNIRP guidelines at the time of publishing.

Artificial Optical Radiation Directive (AORD)

In Europe, further to Article 16(1) of Directive 89/391/EEC of the 12th June 1989, introducing measures to encourage improvements in the safety and health of workers at work, the European Union has adopted a number of additional directives relating to the working environment. Amongst these are a group relating to Physical Agents, such as vibration, noise, electromagnetic fields, and artificial optical radiation.

This latter is introduced in Directive 2006/25/EC, published in the Official Journal of the European Union on the 27th April 2006, to be brought into force in law by 27th April 2010.

The measures introduced are designed to prevent harm to workers, due to exposure of the skin and eyes to coherent and non-coherent artificial sources in the work place.

It is notable that solar radiation is not included in this directive.

This directive refers to EN62471 and EN60825.