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Overview of Measurements
The photobiological safety of lamps is evaluated by the measurement of source irradiance (200-3000nm) and source physiological radiance (300-1400nm), in consideration of six hazards to the skin and eye.
Hazard |
Wavelength Range (nm) |
Quantity |
Bioeffect Eye |
Skin |
Actinic UV skin and eye |
200-400 (weighted) |
Irradiance |
Cornea: photokeratitis Conjunctiva: conjuntivitis Lens: cataractogenesis |
Erythema elastosis |
UVA eye |
315-400 |
Irradiance |
Lens: cataractogenesis |
|
Retinal blue-light |
300-700 (weighted) |
Radiance |
Retina: photoretinitis |
|
Retinal blue-light-small-source |
380-700 (weighted) |
Irradiance |
Retina: photoretinitis |
|
Retinal thermal |
380-1400 (weighted) |
Radiance |
Retina: retinal burn |
|
Retinal thermal-weak visual stimulus |
780-1400 (weighted) |
Radiance |
Retina: retinal burn |
|
Infrared radiation eye |
780-3000 |
Irradiance |
Cornea: corneal burn Lens: cataractogenesis |
|
Thermal skin |
380-3000 |
Irradiance |
Skin burn |
For each hazard an exposure limit is provided which is expressed in terms of dose (irradiance/radiance x time) or irradiance/radiance; comparing measured quantities with such limits permits determining either a permissible exposure time before hazard limit is reached or a pass/fail criteria for given exposure times.
A classification system of 4 risk groups is established based on permissible exposure time before hazard limit is reached.
|
Philosophical Basis |
|---|---|
|
No photobiological hazard |
|
No photobiological hazard under normal behavioural limitations |
|
Does not pose a hazard due to aversion response to bright light or thermal discomfort |
|
Hazardous even for momentary exposure |
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