Laser Safety
Introduction
The word laser is an acronym for Light Amplification by the Stimulated Emission of Radiation. The ‘light’ produced by a laser, a form of non-ionising optical radiation, has a unique combination of spatial coherence (all the waves are in phase); monochromaticity (i.e., have just one colour or a narrow bandwidth) and usually high collimation (i.e., low angular divergence such that the beam does not ‘spread out’ significantly with distance). This combination of characteristics distinguishes laser radiation from all other light sources.
Lasers come in various shapes and forms. They have many uses in teaching, research, manufacturing, medicine, dentistry, shop checkouts and most commonly at work in the office. Lasers emit radiation as narrow concentrated beams of light, not necessarily visible to the human eye. The optical and skin hazards presented by lasers vary markedly according to the wavelength and power of the output. The hazards of lasers are often associated with the ability of the laser beam to damage eyesight or burn skin, but quite often the radiation or optical hazards are not the ones that present the greatest risk, with associated risks from electrical supplies, cryogenic liquids or chemical dyes being more hazardous.
The policy of Queen Mary University of London (Queen Mary) is to ensure that the risks arising from the use of LASERS and devices that produce artificial optical radiation are reduced to a negligible level as far as is reasonably practicable. The objective of the policy is the continued health, safety, and welfare of employees (staff), students and others who may be affected by the risks and this is achieved through risk assessment.
The University requires that ALL Class 3R, 3B and 4 lasers are registered, risk assessed, and suitable control measures implemented.
Safety of laser products. A user's guide - PD IEC/TR 60825-14:2022
Classification
- Class 1 laser products are safe under reasonably foreseeable conditions of operation, including long-term direct intrabeam viewing, even when using optical viewing instruments, for example eye loupes or binoculars.
- Class 1M laser products are usually products that produce beams with a large diameter. Therefore, only a small part of the whole laser beam can enter the eye. As for a Class 1 laser product, they are safe for the naked eye under reasonably foreseeable conditions of operation. However, these laser products can be harmful to the eye if the beam is viewed using magnifying optical instruments.
- Class 2 lasers are limited to a maximum output power of 1 milliwatt or one-thousandth of a watt (abbreviated to mW) and the beam must have a wavelength between 400 and 700 nm. A person receiving an eye exposure from a Class 2 laser beam, either accidentally or as a result of someone else’s deliberate action (misuse) will be protected from injury by their own natural aversion response.
- Class 2M laser products are products which produce beams with a large diameter beam in the wavelength range 400 to 700 nm. Therefore, only a small part of the whole laser beam can enter the eye, and this is limited to 1 mW, similar to a Class 2 laser product. However, these products can be harmful to the eye if the beam is viewed using magnifying optical instruments.
- Class 3R laser products are higher powered devices than Class 1 and Class 2 and may have a maximum output power of 5 mWor 5 times the AEL for a Class 1 laser product. The laser beams from these products exceed the MPE for accidental viewing and can potentially cause eye injuries, but practically the risk of injury in most cases is relatively low for short and unintentional exposure.
- Class 3B laser products may have an output power of up to 500 mW(half a watt). Class 3B laser products may have sufficient power to cause an eye injury, both from the direct beam and from reflections. The higher the radiant power of the device the greater the risk of injury. Class 3B laser products are therefore considered hazardous to the eye. However, the extent and severity of any eye injury arising from an exposure to the laser beam of a Class 3B laser product will depend upon several factors including the radiant power entering the eye and the duration of the exposure. Class 3B laser products which approach the upper limit for the Class may produce minor skin injuries or even pose a risk of igniting flammable materials.
- Class 4 laser products have an output power greater than 500 mW(half a watt). There is no upper restriction on output power. Class 4 laser products are capable of causing injury to both the eye and skin from direct exposure and reflections also may be hazardous. Class 4 laser beams also present a fire hazard. Lasers used for many laser displays, laser surgery and cutting metals may be Class 4 products.
Roles and Responsibilities
Head of School/Institute/Directorate
Heads of S/I/D are responsible for ensuring that all lasers within their area are operated in accordance with this policy, and where appropriate, identifying a suitable person to act as School Laser Safety Officer. The appointment should be confirmed in writing and documented within their local Health and Safety management arrangements.
University Laser Safety Officer (ULSO)
The ULSO is appointed by the Director of the Health and Safety Directorate and is responsible for the provision of advice and guidance to, S/I/D on the implementation of this policy in relation to relevant legislation and British Standards.
Maintains a university inventory of relevant lasers, provides advice to departments on appropriate risk assessments and the required level of control and is responsible for coordinating University wide training on laser for School laser Safety Officers and Laser Users.
School Laser Safety Officer (SLSO)
Is appointed, by the Head of S/I/D whenever Class 3 or above lasers are operated are responsible for maintaining a record of all relevant lasers in the department, this includes any embedded laser in a lower class product that might be exposed during routine servicing or maintenance.
They are also responsible for providing advice to research supervisors on the process of laser risk assessment and the appropriate level of control and ensuring compliance with the University Policy.
Link to list of School Laser Safety Officers (Coming soon)
Line Manager / PI
Line Managers / PI’s are responsible for ensuring their lasers are operated in accordance with this policy.
Laser users
Must make themselves aware of the requirements of the local rules and seek clarification if these are not fully understood, only undertake work once suitably trained and to highlight any issue or problems to their line manager/PI.
Obtaining Lasers
No lasers should be purchased or brought onto our campuses without prior approval from your SLSO and the ULSO.
Further information and guidance please contact your SLSO and/or the ULSO.
Registration
All Class 3R, 3B, 4 and Class 1 items that contain a higher power laser which may reasonably be accessed e.g., during a service visit must be registered.
Risk assessment
Prior to commencing work a valid approved laser risk assessment must be implemented. Please consult your SLSO (or the ULSO in their absence) for advice and guidance on the preparation of this.
Safe system of work
A safe system of work should be in place to inform all users of the procedures and processes for working with a laser system.
Local Rules
All designated laser areas should have local rules to inform users of the management arrangements for the facility.
Training
All users must undergo University laser awareness training (coming soon) and local training on the specific lasers/systems within their work area.
Laser pointers
Laser pointers sold in the UK should be classified in accordance with the current British Standard on laser safety (BS60825 -1). This document specifies requirements for the manufacturers of laser products to ensure that the risk of accidental exposure is minimised through the use of engineering control features and product labelling, and by specifying minimum requirements for the supply of product information to allow for their safe use.
Link to guidance note (coming soon)
Templates
Local rules doc (coming soon)
For Advice and Assistance at QMUL, contact the H&S Manager / Advisor for your Faculty / PS or the subject lead at http://www.hsd.qmul.ac.uk/contact-us/
All H&S staff can be contacted via the help desk at hs-helpdesk@qmul.ac.uk
