Green lasers - responsible use and registration
Green laser pointers have become an indispensable tool for astronomers giving a guided sky tour, and are very useful for telescopic observers for locating and pointing out targets of interest. Unfortunately, incidents of irresponsible laser use have occurred, as reported here and elsewhere.
During the 2010 ASSA Symposium (Oct 7-9, Pretoria) a group of astronomers and other interested parties discussed the use of these lasers, with special reference to their legal status.
Recommendations and points for discussion were published on the ASSA Pretoria Centre's website (laser safety page) and input from the broader astronomical community encouraged.
On October 27, Andrie van der Linde, one of the laser-safety campaigners, gave a talk to the ASSA Cape Centre to share some of the thoughts and concerns expressed during the special meeting in Pretoria. What follows are my notes of his presentation.
Hazardous Substances Act No. 15 of 1973
To provide for the control of substances which may cause injury or ill-health to or death of human beings by reason of their toxic, corrosive, irritant, strongly sensitizing or flammable nature of the generation of pressure thereby in certain circumstances and for the control of certain electronic products.
To provide for the division of such substances or products into groups in relation to the degree of danger.
To provide for the prohibition and control of the importation, manufacture, sale, use, operation, application, modification, disposal or dumping of such substances and products.
(read the full Act)
Schedule of Listed Products
Regulation No. R. 1302, 14 June 1991 (Hazardous Substances Act, No. 15 of 1973)
Any electronic product emitting coherent electromagnetic radiation produced by stimulated emission, namely all laser products that emit radiation in excess of 0.8 x 10-9 watt in the wavelength region up to and including 400 nm or that emit radiation in excess of 0.39 x 10-6 watt* in the wavelength region greater than 400 nm.
(download the Regulation)
*This is about 1000x weaker than a 5mW laser pointer.
Class 1. Safe for all conceivable circumstances (incl. totally enclosed Class 4)
Class 1(M): Safe unless optical if optical magnifiers used
Class 2: Visible lasers with 1 mW limit
Class 3R: < 5 mW. Continuous wave/visible (safe for accidental eye exposure)
Class 3B: < 500 mW (unsafe for eyes under all conditions. Safe for direct skin exposure and for diffused exposure of eyes)
Class 4: Unsafe for eyes, skin and diffused reflections. Fire hazard.
Recommendation: Safe practices at group events
Class 3B (> 5 mW) lasers should be used by knowledgeable astronomers under controlled circumstances.
1. do not point at people, aircraft or animals
2. keep at a suitable distance from the audience
3. warn the audience
4. area should be clear of obstacles
5. avoid surfaces that can give specular reflections
6. minimise use
7. keep away from children
8. lasers should switch off when switch is released
I asked Johan Uys of the Department of Health for straight answers to some burning questions:
1. I have a green laser pointer. How do I know if it is legal?
"You could ask the dealer/importer (where you bought the laser pointer) for the import licence number of the device as issued by the Directorate: Radiation Control or you could contact me, Johan Uys on tel. no. 021-9577450."
2. How do I register my laser? (I know who the importer is)
"Any Class 3B or Class 4 laser system must also be licensed for use. Contact me to acquire the application form"
Or you can download the form as a PDF: Form SBLN-1 - Application for licence to use a non-medical laser.
3. How do I register my laser? (I don't know who the importer is)
"If it is a Class 3B laser pointer used only by a "presenting astronomer", then contact me as indicated above."
4. What is a Laser Safety Officer?
"A Laser Safety Officer (LSO) is any person who has authority to monitor and enforce the control of laser hazards and has the responsibility for oversight of the control of laser hazards. The "presenting astronomer" will be the LSO but in the medical field where for example a laser is used for surgery or in an industrial situation, the LSO could be the surgeon, industrial hygienist, radiation protection officer, safety engineer, laser specialist, laser operator, etc."
5. I want to register as a Laser Safety Officer. What do I do?
Contact Johan Uys on tel. no. 021-9577450.
nothing more to see. please move along.