Lamp and LED safety – classification vs. realistic exposure analysis

Abstract

The international lamp safety standard IEC 62471 “Photobiological safety of lamps and lamp systems” defines criteria to classify lamps into one of four risk groups (exempt, RG1, RG2, RG3). RG3 is referred to as “high risk” and is usually not considered as appropriate as a consumer product unless made safe by the housing (the luminaire or the lamp system). While the exempt group and RG1 is usually accepted as “safe”, there are concerns – particularly for LEDs – if RG2 is appropriate for lighting of rooms or streets, or as consumer products without a warning label. To support a balanced view of the actual risk associated to the use of a product, this paper discusses the rules of how to determine the risk group. Strictly speaking IEC 62471:2006 requires risk group classification only for lamps and not for luminaires or lamp systems. Due to different reasons, the risk group might not reflect the actual risk: small assumed eye movements, wide ranges of permitted exposure durations per risk group as well as safety margins between limits and injury thresholds. For lighting and many other applications, for instance, RG2 when associated with visible light emission can probably be considered as sufficiently safe for consumer products even without warning labels. When UV emission is not an issue, it can be argued that for regular lamps and luminaires, risk group classification does not appear to be necessary. We also argue that it is not justified to consider LEDs differently than other, conventional light sources in a discussion about retinal hazards.The international lamp safety standard IEC 62471 “Photobiological safety of lamps and lamp systems” defines criteria to classify lamps into one of four risk groups (exempt, RG1, RG2, RG3). RG3 is referred to as “high risk” and is usually not considered as appropriate as a consumer product unless made safe by the housing (the luminaire or the lamp system). While the exempt group and RG1 is usually accepted as “safe”, there are concerns – particularly for LEDs – if RG2 is appropriate for lighting of rooms or streets, or as consumer products without a warning label. To support a balanced view of the actual risk associated to the use of a product, this paper discusses the rules of how to determine the risk group. Strictly speaking IEC 62471:2006 requires risk group classification only for lamps and not for luminaires or lamp systems. Due to different reasons, the risk group might not reflect the actual risk: small assumed eye movements, wide ranges of permitted exposure durations per risk group as well as saf...