Class 1 or 2 laser pointers, as labelled, should be used for presentation purposes within the University. The power output of these devices is unlikely to pose a significant risk. Users though should exercise caution so as to avoid pointing the beam at any individual.
Some laser pointers are now available with quoted output powers of up to, or even over, 50mW, thus placing them in the higher class of lasers (i.e. Class 3R, 3B or 4). These pose a significant risk of injury, particularly as the likelihood of exposure from either direct or specular reflections is reasonably foreseeable when pointers are used for lectures and presentations.
In addition, the classification of laser pointers from certain suppliers has been shown to be inadequate. This is particularly concerning with the introduction of green laser pointers. The eye is more sensitive to green light and so, although the power output may be similar, a green laser will appear brighter than say, a red laser. A correctly classified low powered green laser pointer should still pose a low risk, but individuals may experience some form of after image when it is displayed on a projection screen, particularly when viewed from close-by. If the green laser pointer is incorrectly classified, particularly one that emits a pulse of energy, then the risk may be significant.
Individuals must ensure that laser pointers are obtained from reputable suppliers and that they are correctly classified. Lasers marked Class 3R, 3B or 4, or where the known output power is greater than 1mW, or whenever there is any uncertainty, must not be used as laser pointers without first obtaining written approval from the University Safety Office.