Radiation Safety

Laser Hazard Classification

Class 1
1. Not capable of emitting in excess of the Class 1 AEL
2. Most lasers in this class are lasers which are in an enclosure which prohibits or limits access to the laser radiation
Class 2a
1. Lasers in the visible region of the spectrum which do not exceed the Class 1 AEL for exposure less than or equal to 10E3 s
2. The output of the laser is not intended to be viewed
3. An example of a Class 2a laser is a supermarket point-of-sale scanner
Class 2
1. All Class 2 lasers are in the visible region of the spectrum
2. Continuous wave lasers which can emit accessible radiant power which exceeds the Class 1 AEL for the maximum duration inherent in the laser, but do not exceed 1 mW
3. Pulsed lasers which can emit accessible radiant power which exceeds the Class 1 AEL for the maximum duration inherent in the laser, but not do not exceed the Class 1 AEL for an exposure of 0.25 s
Class 3a
1. Have output that is greater than or equal to 5 times Class 2 AELs
Class 3b
1. Continuous wave - between the Class 3a limits and 500 mW
2. Repetitively pulsed - radiant energy between 30-150 mJ per pulse for visible and infrared, otherwise greater than 125 mJ per pulse; average power less than 500 mW
Class 4
- Limits exceed Class 3b limits

Contact the Division of Research Safety, Radiation Safety Section (333-2755 or via e-mail) or visit our website: http://www.drs.illinois.edu/rss/.

Other Radiation Safety Fact Sheets are available from the Radiation Safety Section at our website: http://www.drs.illinois.edu/rss/factsheets/.