Laser safety

Class 1 or 2 laser pointers, as labelled, should be used for presentation purposes within the University.  The power output of these devices is unlikely to pose a significant risk.  Users though should exercise caution so as to avoid pointing the beam at any individual.

Some laser pointers are now available with quoted output powers of up to, or even over, 50mW, thus placing them in the higher class of lasers (i.e. Class 3R, 3B or 4). These pose a significant risk of injury, particularly as the likelihood of exposure from either direct or specular reflections is reasonably foreseeable when pointers are used for lectures and presentations.

In addition, the classification of laser pointers from certain suppliers has been shown to be inadequate. This is particularly concerning with the introduction of green laser pointers. The eye is more sensitive to green light and so, although the power output may be similar, a green laser will appear brighter than say, a red laser. A correctly classified low powered green laser pointer should still pose a low risk, but individuals may experience some form of after image when it is displayed on a projection screen, particularly when viewed from close-by. If the green laser pointer is incorrectly classified, particularly one that emits a pulse of energy, then the risk may be significant.

Individuals must ensure that laser pointers are obtained from reputable suppliers and that they are correctly classified.  Lasers marked Class 3R, 3B or 4, or where the known output power is greater than 1mW, or whenever there is any uncertainty, must not be used as laser pointers without first obtaining written approval from the University Safety Office.

No. These are Class 1 products, such that any high powered laser is fully contained inside the equipment’s protective casing thus preventing anyone from being exposed to the beam. If, however, there is a need to remove the protective casing and operate the high powered laser at the same time, then this would warrant closer attention and the University Safety Office should be consulted.

A Departmental Laser Supervisor must be appointed by the head of department whenever Class 3R, 3B or 4 lasers are operated, including any embedded laser in a lower class product that might be exposed during routine servicing or maintenance.

The University Safety Office must be notified in writing whenever a Departmental Laser Supervisor is appointed or when the person undertaking this role changes.  The Safety Office will arrange suitable training for the Departmental Laser Supervisor. 

The department’s Statement of Safety Organisation should also be updated to reflect the new Departmental Laser Supervisor and members of the department should be notified.

Where an assessment identifies a specific risk with a laser system, then a hierarchy of control must be followed. For non-beam hazards these are outlined within individual University Policy Statements. For beam hazards, the University’s preferred starting point for all lasers is fully enclosed with fixed guarding.

If a risk assessment identifies that it is not practical to fully enclose the laser at all times, then it must be justified within the assessment and a suitable combination of engineering, administrative and personal protective controls identified. In any event, the use of personal protective equipment must always be the last option and if it is necessary, there must be clear administrative controls to ensure it is correctly applied.

If localised enclosures/guarding is not possible, then as a minimum all laser tables must be fitted with appropriate side shields.

LASER CONTROL MEASURES

Your supervisor must determine the need for laser eye protection as part of the risk assessment process.  Laser eye protection should only be used if all other types of controls have first been considered and where a risk of exposure to a laser above the Maximum Permissible Exposure limit still remains. 

Where laser eye protection is deemed necessary, then the following must be applied:

• There must be a documented in-house assessment of the required specification of eyewear for each type of laser, taking into account the varying wavelengths used and the degree of optical clarity required.  The assessment must state both the optical density and ‘scale factor’ attenuation for all relevant wavelengths. It is not appropriate to rely on laser equipment suppliers to undertake this assessment or specify eyewear. Eyewear must be selected against the relevant standard, BS EN 207 for general use and BS EN 208 for alignment procedures.

• There must be evidence, either on the frames or in accompanying documents, that the eyewear used is CE marked and conforms to the required standard. Eyewear that does not meet these requirements must be replaced.

• The protective eyewear should be labelled indicating which laser(s) and wavelengths they are suitable for.  

• Where multiple lasers are used in a single area, then each set of protective eyewear must be unambiguously marked to ensure correct selection for the relevant laser.

• When not in use, protective eyewear must be stored correctly to prevent damage. It must not be left on benches but stored in protective cases or suitable racking.

• Individuals must be trained in the selection, fitting, storage, and inspection of protective eyewear.

LASER RISK ASSESSMENTS

Only suitably trained individuals are permitted to work with open beam lasers. Your supervisor must identify the appropriate level of training required and this should be outlined within the local rules covering your laser.  Where a level of risk differs depending on the various laser operations (e.g. during alignment), then additional training requirements must also be outlined within the local rules.

You must be authorised by your supervisor before operating a laser and an individual training record must be maintained. The Laser User Authorisation/Training Record (LS-4) can be used for this purpose. Your training record should give an indication of what you can or cannot do and any additional supervision that might be required.  It is up to your supervisor to make this judgement. This includes individuals who have received training in other departments or establishments. Consideration must also be given to the competency of visitors and contractors before permitting access to lasers.

As a starting point, all users of open beam lasers must undertake the University’s Introduction to Laser Safety Course.

VIEW SAFETY TRAINING

The University does not require you to undergo a routine ophthalmic examination before operating a laser.  However, if you have any pathological condition of the eye, you are asked to consult the University Occupational Health Service prior to commencing laser use.

Your department should reiterate this point by asking you to complete the user declaration in the LS-4 Laser User Training Record

All lasers should conform to British Standard BS EN 60825-1 and an overview of the laser details must be given to your Departmental Laser Supervisor as part of the laser registration process. 

LASER REGISTRATION PROCESS

If the laser does not conform to BS EN 60825-1, then this must be discussed with your Departmental Laser Supervisor and information should be provided as to what other relevant standards are applicable. For example, some medical lasers might adequately conform to BS EN 60601-2-22. However, lasers that are manufactured in countries outside the European Union might be supplied in accordance with international standards or even local standards, such as the American standard ANSI Z136. In these cases, the supplier should be asked to confirm that their supplied laser conforms to the British Standard, particularly as the laser classification system may differ in other countries.

 Individuals should also be aware that some suppliers will supply lasers as ‘components’ for incorporating into other systems.  Where laser components are ‘fully functional’ at the time of purchase (i.e. the laser can simply be turned on), then it is up to the supplier to ensure that the laser conforms to the British Standard. If the laser is not fully functional, then individuals should be aware that the full requirements of the British Standard may not apply meaning certain basic control measures, such as key controls, interlock connections and labelling may not be present with the laser. This is particularly true for laser diode products. Individuals should try to avoid these problems by checking with the supplier as to the conformity status before purchasing.  If this cannot be avoided, then you must discuss this with the Departmental Laser Supervisor to ensure adequate controls can be achieved.

Other factors to consider when purchasing a new laser are:

• Have I started the risk assessment process?
• Does the risk assessment justify the type of laser to be purchased or could a lower powered or safer alternative be obtained?
• What additional controls has the risk assessment identified i.e. shutters, interlock designs, beam stops, barriers, screens, fume cupboards etc.  Are these controls compatible with the laser?
• What problems might be encountered during its installation (particularly if the laser is large and heavy), such as the route, need for lifting equipment, door and room entry requirements?
• What supply specifications are required, such as electrical, cooling, lighting, ventilation, circulation routes, and storage requirements for power supplies, cooling equipment, cabling, and protective eyewear or clothing?
• How will I dispose of the laser? Can the supplier take away the redundant laser under the Waste Electrical and Electronic Equipment (WEEE) Regulations?

A contractor who requires a high powered beam to be exposed and operated during their servicing and maintenance should be asked to supply their own risk assessment and method statement. The University Safety Office should be notified whenever a contractor refuses to supply these documents. The contractor’s risk assessment/method statement should be reviewed in line with the University’s laser policy to ensure an acceptable method of working is undertaken. 

It may be necessary to assign a temporary ‘Laser Controlled Area’ to a room in order for the work to take place. This may require temporary signage or door entry restrictions. This should be agreed with the contractor and the arrangements documented, either within the method statement or as a Permit to Work. Further information on the use of permits to work is outlined in the University’s policy S6/08 – Contractors working on University Premises.

Yes, unless an alternative method of key control has been agreed with your Departmental Laser Supervisor as part of the local rules. 

Standard precautions are set out for ‘Laser Controlled Areas’ within the British Standard 60825-14. For Class 3B or 4 lasers, this prescribes the need to “ensure key security”. This means that the operating key should be removed whenever the laser is not in use, so as to ensure and demonstrate that only those suitably trained and authorised are able to operate a particular laser. It is best practice to remove the key and keep this under the control of the supervisor with a record of use maintained. It should not be possible for a non-authorised person to access a laser laboratory and be able to simply turn on a Class 3B or 4 laser. Therefore, the use of room access controls, key presses, defined key storage areas and the removal of keys after use all help achieve this requirement.

The Departmental Laser Supervisor is expected to maintain a inventory of all relevant lasers within the department. On an annual basis, normally at the beginning of the academic year, the Departmental Laser Supervisor is asked to forward a copy of this inventory to the University Laser Safety Officer (University Safety Office).

In addition, the Departmental Laser Supervisor is expected to conduct an inspection of all relevant laser systems each year. They should formally report their findings to the Departmental Safety Advisory Committee. The minutes from these meetings and any supplementary report should then be forwarded to the University Safety Office.

LASER INVENTORY

Lasers are generally classed as Waste Electrical and Electronic Equipment (WEEE). Therefore, whenever a new laser is purchased to replace an old laser, the supplier should be asked to dispose of the old laser as part of the purchase.

If it is not possible to dispose of a laser through a supplier’s own scheme, then the University Safety Office should be consulted. The following details are required:

• Number of lasers.
• Type of lasers (e.g. Argon, HeNe).
• Confirmation as to whether it is just the laser head or does it contains a separate power supply.
• If it contains the power supply, can all external electrical leads be cut-off, removed or separated.
• Dimensions of the laser head (mainly, how long is it?).
• Estimated weight per laser (if known).
• Any additional information you can supply e.g. make, model, serial number, manufacture year, power, wavelength etc..

The University Safety Office will then advise on the correct means of disposal.

Currently, the University Safety Office does not hold a laser power meter, but if you require such a device please contact the office.