Laser Safety

Lasers are capable of producing intense, collimated beams of light at specific wavelengths (visible, ultra violet and infrared). While lasers vary greatly in power output, wavelength and purpose, the hazard potential for eyes and skin can be significant due to the concentrated energy density. AS/NZS IEC 60825.1:2011 Safety of laser products Part 1: Equipment classification and Requirements and AS/NZS IEC 60825.14:2011 Safety of laser products Part 14: A user's guide are the principal documents for laser safety.

1. Laser classification

Lasers are divided into seven classes according to accessible emission limits.

NB Modifications can increase the class and subsequent hazard of a laser.

Class 1

Are safe under most circumstances and are incapable of damaging the eyes or skin because of either engineered design or inherently low power output

Class 1M

Emit in the wavelength range 302.5 - 4000nm and may be hazardous if optics are used in the beam

Class 2

Emit in the visible wavelength range 400 - 700nm and have sufficient power output to cause damage to the eyes if viewed continuously. However, their outputs are low enough where eye protection is afforded by the blinking reflex. Additional hazard control measures take the form of cautionary signs or labels

Class 2M

Are similar to Class 2 however viewing may be more hazardous if the user employs optics within the beam

Class 3R

Emit in the wavelength range 302.5 - 106nm and have the potential to cause damage to the eyes from intra-beam viewing but the risk is lower than for Class 3B lasers. Precautions are required to prevent both direct viewing and viewing with optical instruments

Class 3B

Are more hazardous because of either higher output or operation outside visible wavelengths. In addition, beam reflections may also be hazardous. More stringent controls are needed to prevent exposure than with lower power lasers.

Class 4

Are high power devices capable of producing eye damage even from diffuse reflection. They may cause skin injuries and could also constitute a fire hazard.

2. Health effects of laser use

Eye

Eyes are the most susceptible to damage from lasers. Different parts of the eyes are susceptible to different wavelengths. Damage can occur from heating, photochemical reactions and explosive rupture. Appropriate controls are essential to prevent ocular damage

Skin

Skin is less at risk from damage caused by lasers, but exposure to lasers still need to be managed appropriately to minimise the potential for skin burns

Other

In addition to laser radiation, there are additional hazards such as collateral radiation, electrical shock, fire, cryogenics, mechanical hazards, vapours and chemicals, which all need to be considered when completing a risk assessment

3. Risk Management

Laser hazards may be controlled by the use of engineered controls, administrative controls and personal protective equipment, either singly or in combination. As a general principle, engineered controls are preferred where appreciable hazards exist, although these may need to be supplemented by the use of appropriate eye protection.

The control measures and the associated requirements of all laser classifications are listed in detail in AS/NZS IEC 60825.1:2011 Safety of laser products Part 1: Equipment classification and Requirements

Engineering Controls

Lasers require certain built-in safety features dependent on their classification. These engineering control measures incorporated into the design of the laser system may include:

  • Protective housings
  • Remote interlocks
  • Access panels
  • Master switches
  • Enclosed or semi-enclosed beam paths

Administration Controls

To aid in managing the risk associated with the use of lasers, the following controls are to be implemented where lasers are used:

  • Appointing a Laser Safety Officer
  • Safe Working Procedures
  • User Registration
  • Training
  • Record Keeping
  • Correct Labelling of Device
  • Eye and Skin Examinations

Personal Protective Equipment

The main form of PPE is protective eyewear, but in the case of class 4 lasers should also include protective clothing and footwear. Details on protective eyewear can be found in AS/NZS 1337.4 and AS/NZS 1337.5.

4. Laser safety officer

A Laser Safety Officer (LSO) is a designated school/departmental staff member who has received training to an appropriate level and is knowledgeable in the evaluation and control of laser hazards. The LSO would have responsibility for the suitable training of laser users and oversight of the control of laser hazards. At Monash University, a Laser Safety Officer must be appointed where Class 3 or 4 lasers are used.

For further information, please contact the Radiation Protection Officer, Occupational Health and Safety on:

5. Laser Safety Training Notes

This is a copy of the Power Point presentation from the laser safety user training.

6. Laser Pointers and Prohibited Weapons

Laser pointers are hand-held, battery-operated articles designed or adapted to emit a laser beam. With sufficient power, laser pointers can caused serious, irreversible eye damage and are classed as Prohibited Weapons under the Control of Weapons Act 1990 (Vic).

Legal Lasers Pointers

Most laser pointers that are commercially available are limited to safe power levels (1 milliwatt or less). Laser pointers that are rated as Class 1 are safe, laser pointers that are Class 2 are hazardous if the beam is stared into, but for the most part are still safe.

Prohibited Weapons

Laser pointers that are Class 3R, Class 3A (outdated classification), Class 3B or Class 4 are capable of doing severe damage to the eye. Class 4 laser pointers are now commercially available from overseas suppliers, and have sufficient power to cause skin burns and instantaneous, irreversible eye damage.

Lasers that emit with a power greater than 1 miliwatt (i.e. Class 3R, 3A, 3B and 4) are classified as Prohibited Weapons and it is an offense to import, sell, manufacture, possess and user laser pointers of these type. Penalty for possession is $28,668 or 2 years imprisonment.

Exemptions for Research Purposes

Monash University strictly prohibits the use of laser pointers that are not Class 1 and Class 2 on all of its premises without an appropriate permit and risk controls.

A permit can be applied for from the Victorian Police.

Further Information

Victorian Police Controlled Weapons

Occupational Health and Safety

Telephone: 990 51016

Fax: 9905 2580

Email: ohsehelpline@monash.edu

References

  • AS/NZS IEC 60825.1:2011 Safety of laser products Part 1: Equipment classification and Requirements
  • AS/NZS IEC 60825.14:2011 Safety of laser products Part 14: A user's guide
  • AS/NZS 1337.4 Personal eye-protection - Filters and eye-protectors against laser radiation (laser eye-protectors)
  • AS/NZS 1337.5 Personal eye-protection - Eye-protectors for adjustment work on lasers and laser systems (laser adjustment eye-protectors)
  • University of Queensland, Laser Safety Guidelines