Publications

• Publications Home
• Information sheets
• The Source newsletter
• NRL reports: 1990 - present
• NRL reports: archives
• Environmental annual reports
• Regulatory publications
• Miscellaneous publications

Information Sheet No. 20

Reviewed July 2009

This publication can be downloaded as a PDF (37 kB)

Laser Safety

A laser (Light Amplification by Stimulated Emission of Radiation) is a source of high intensity radiation, often in the visible part of the spectrum (such as the red lasers used in bar code scanners at the supermarket) but also in the invisible infra-red and UV bands.  Although the total power output may be very low, the beam can be focused to concentrate the energy onto a very small spot.

There are many types of lasers, with both continuous and pulsed beams.  They are used widely in surveying, building, tunnelling, surgery, in all kinds of cutting jobs, and in control systems (such as the control of tractors pulling ploughs, or ditch diggers).  Lasers are also a tool in various forms of communication and in research.

The most common health risk with lasers is the possibility of damage to the eye.  Powerful medical and industrial lasers can also burn skin, and may pose additional risks, such as fire.  Although low-powered lasers might not cause permanent harm, viewing them may dazzle, distract or annoy.

In Australasia lasers and products incorporating lasers are grouped into classes, depending on the hazards they pose.  (Similar systems of classification are used elsewhere in the world.)

Class 1

produces very low power and are safe under all reasonably foreseeable conditions of operation. Lasers of this class are found in compact disc players.  No special precautions are required.

Class 1M

produces either a large diameter beam or a highly divergent beam.  The beam may be hazardous if viewed through magnifying optical instruments.  Some of the lasers used for fibre-optic communication systems are Class 1M laser products.

Class 2

produces visible beams, of greater power than Class 1.  The brightness of the beam normally causes the eyes to be averted, or blink, well before any permanent damage occurs.  Deliberate staring into the beam should be avoided.  Lasers in this class can be found in laser printers and supermarket scanners.

Class 2M

produces either a large diameter beam or a highly divergent beam.  When viewed with the naked eye, the hazards are the same as for a Class 2 laser.  The risk of harm is greater if the beam is viewed through magnifying optical instruments.  Some lasers used for surveying fall in this Class.

Class 3R

produces low power, but greater than Class 2 limits.  Direct viewing of the beam is potentially hazardous, but less so than for Class 3B lasers, especially if not viewed through optical magnifiers.  (Optical magnifiers include telescopes and binoculars, but not prescription eyeglasses or contact lenses.)  Lasers in this class may be used in alignment products.

Class 3B

produces moderately high power.  Direct and mirror reflected beams can be hazardous to eyes.  For higher outputs within this Class diffuse reflections also may be hazardous to eyes at short ranges.   These lasers may be used in medical applications and research.

Class 4

produces high output.  Direct and mirror reflected beams are hazardous to eyes and usually skin.  Eyes may also be harmed by diffuse reflections.  The beam may also constitute a fire hazard.  Class 4 lasers can be found in the metal industry, research laboratories, and laser light shows.

A laser product classified in a low class (eg, Class 1) may incorporate a laser of a higher class.  The product must contain interlocks which prevent accidental exposure to the beam of the enclosed laser.

Further information on lasers and laser safety is contained in AS/NZS 2211.1:2004 Laser safety.  Although compliance with this Standard is not directly mandated in any legislation, it would most likely be referenced in any dispute about the safety of a laser or laser product and its application.  Users would be unwise to disregard the recommendations of this Standard.

Additional information on lasers used for medical purposes is given in AS/NZS 4173:2004 Guide to the safe use of lasers in health care.  NRL information sheet IS24 contains information about laser pointers.

For further information, contact:

National Radiation Laboratory
P O Box 25099
Christchurch
New Zealand

Phone:

+ 64 3 366 5059

Fax:

+ 64 3 366 1156

Internet:

http://www.nrl.moh.govt.nz

Back to top: