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Answer by labsupport on question Answer by j.turnbull on question laser classification

Submitted by sat on 08 September 2014

Dear Keryn

It is my understanding that this laser would still be classified as Class 3 under the current classification system (probably Class 3R).  The upper output for Class 2 visible lasers is 1mW.  At or below this power eye injury is considered very unlikely because of the natural human aversion responses (blinking, turning away).  Class 3R visible lasers fall into the 1- 5 mW power range, eye injury is possible, and so extra precautions are required for their use.

The possible reclassification of former Class 3 lasers to the current Classes 1M or 2M refers to situations where the laser can exceed the permitted accessible emission limit (AEL) for Class 1 or Class 2 (that is, 1mW), but because of the geometrical spread of the radiation, can not cause harmful levels of exposure to the unaided eye (see pages 75- 76).  This would not apply to a bench laser because the beam is collimated and is not “geometrically spread”, and so eye injury remains possible.

It is noted that this instrument is classified as Class 3, and with 3mW power output by the manufacturer (Laser Services), however the instruction sheet indicates a power output of 0.5mW (consistent with a Class 2 laser).  It would be prudent here to follow the classification on the instrument rather than external printed notes.  This classification could be checked with Laser Services.   For contact details see http://www.laserservices.com.au/reception/shopcustcontact.asp

It is also noted that the use of Class 3R visible lasers in schools is not prohibited in this Safety Guide. While it states “It is expected that in most circumstances only Class 1 and Class 2 laser products should need to be used in schools” (page 65), the use of Class 3R lasers is not uncommon in senior Physics applications.  This Safety Guide gives extensive advice on this, particularly in Sections 9.3, 9.5, 9.6 (pages 81- 82), and also in Section 10, Developing a Risk Assessment (Section 10.1, pages 85- 86). This includes the requirement for teaching situations in schools for specific policies and permissions required for the use of lasers above class 2. It is also important to consult with your jurisdiction in case there are additional restrictions in place in your school system.

Reference:

ARPANSA: Safety Guide for the Use of Radiation in Schools (2012) See http://www.arpansa.gov.au/pubs/rps/RPS18.pdf 

Peter Turnbull