All CoolLED pE LED products use high intensity LED arrays which are potentially harmful if due consideration to safety issues are not applied.  A safety interlock is provided so that its removal from the microscope (or removal of a Light-Guide, where applicable) will cause the unit to shut down immediately.  

Until recently all LED products were covered by the Laser Safety standard EN60825.  CoolLED's pE products have been designed to include interlocks, allowing them to be classified as Class 1.

LEDs are now to be classified under EN62471:2008, “Photobiological Safety of Lamps and Lamp Systems” which cover a broader range of light sources including mercury and metal halide. Although the risk from LEDs is considerably lower than from conventional high-pressure lamp due to their limited bandwidth, the operator should ensure that he or she does not expose their eyes to the collimated light beam or from the light guides.

The main area of risk is from UV radiation which cannot be seen by the human eye but where the eye is particularly sensitive to damage.  As LEDs are at specified wavelengths, it is those LEDs at wavelengths below 400nm where most care should be taken. CoolLED LED products do not use Mercury, unlike HBO or Metal-Halide lamps. Mercury-based light sources offer the convenience of broad spectrum excitation but can be very intense in the UV.  Risk of eye damage exists from a Mercury source (as well as damage to samples due to undesirable bleaching).  In addition, Mercury is a hazardous substance.  There is a worldwide shift away from the production and use of Mercury as alternative materials become available.  In the case of fluorescence excitation, LEDs now offer such an alternative.

The use and disposal of Mercury is subject to legislation in many countries.  Operators of Mercury-based light sources are aware of the potential hazards to personal health.  More information can be found by Internet search.