Laser inventory

For those departments that have, or are likely to have, high-risk laser systems, the University expects them to maintain a laser inventory of all lasers.

All lasers should be classified according to the British Standard BS EN 60825-1:2014. If this isn't possible, it's sufficient to refer to a separate (i.e. ANSI Z136) or older (i.e. pre-2002) classification system when completing risk assessments, but individuals using lasers classified under a separate system must be suitably trained in the different classifications.

Lasers and laser products supplied by manufacturers from within the EU will be classified according to the British Standard BS EN 60825-1+A11:2021. Departments who make lasers or obtain lasers from non-EU suppliers must ensure they're properly classified and meet all relevant European Standards.

This is a complex matter and although the use of commercially available software can be used as an aid to classification (LaserBee software is available via the University Safety Office), departments may need to obtain external assistance to ensure the full requirements of BS EN 60825-1 and other standards are met.

Descriptions of all classes of lasers, according to BS EN 60825-1

Class 1

Laser products, which are safe under reasonably foreseeable conditions of operation, either because of the low emission of the laser itself, or because of its engineering design such that it is totally enclosed and human access to higher levels is not possible under normal operation. 

Note:  If access panels of a totally enclosed system are removed for servicing etc. then the laser product is no longer Class 1 and the precautions applicable to the embedded laser must be applied until the panels are replaced.  It is important that when such systems are installed in open areas, the potential for this should be considered prior to first installing the system.

Class 1M

Laser products emitting in the wavelength range 302.5 nm to 4000 nm, whose total output is in excess of that normally permitted in Class 1 laser products but because of their very low power density, large beam diameter, or high divergence does not pose a hazard in normal use.  However, they may be hazardous to the eyes under certain conditions if gathering optics (e.g. binocular, telescope, and microscope lens) are used with them.

Class 1C

Any laser product which is designed explicitly for contact application to the skin or tissue, but the ocular hazard is prevented by engineering means (i.e. it must be in contact with the skin to enable the laser radiation to be emitted) and through following the instructions provided with the product.

Class 2

Lasers that only emit visible radiation (i.e. 400 nm to 700nm) and whose output is such that they are safe for accidental viewing because a person’s natural aversion response (i.e. blink reflex, moving head) provides adequate protection under reasonably foreseeable conditions.

Class 2M

Lasers that only emit visible radiation (i.e. 400 nm to 700nm) and whose total output is in excess of that normally permitted in Class 2 laser products but because of their very low power density, beam diameter, or high divergence does not pose a hazard for accidental viewing due to the aversion response.

Class 3R

Lasers that emit in the wavelength range from 180 nm to 1 mm where direct intrabeam viewing is potentially hazardous but the risk is lower than for Class 3B lasers.

Class 3B

Lasers that are normally hazardous when direct intrabeam exposure occurs (i.e. within the Norminal Ocular Hazard Distance (NOHD), which is the distance within which the beam irradiance and radiant exposure will exceed the appropriate MPE).  Viewing diffuse reflections is normally safe, but exposure to specular/mirror reflections could be a significant risk. 

Class 4

High power lasers that are not only a serious risk to the eyes, but may also cause skin injuries.  Even diffuse reflections may be hazardous.  They constitute a fire hazard and can cause hazardous fumes to be produced.

A laser inventory must be maintained by the departmental laser supervisor (DLS) for all high-risk laser systems. These are defined as:  

  • any system where there's a foreseeable risk of exposure to a Class 3R, 3B or 4 laser beam 
  • any modification to a Class 1, 1M, 1C, 2 or 2M laser that increases the hazard above the maximum permissible exposure limit
  • where there's a foreseeable risk of exposure to an embedded higher-powered laser by the intentional removal of enclosures or interlocks, including servicing or maintenance 

Supervisors must ensure that all relevant lasers under their control are registered with the DLS. In particular, they must notify the DLS before use of any new laser. This includes those that are obtained from other departments and any laser that is temporarily on loan or to be used by contractors to undergo specific activities, such as cleaning. The Laser Registration Form (LS-1) can be used for this purpose.

The DLS must forward an updated version of the inventory to the Safety Office on an annual basis.

The DLS should contact the department's academic supervisors on an annual basis and check that all lasers have been registered with them. This list will constitute the department’s laser inventory.

The laser inventory should then be sent to the university laser safety officer, so a centralised inventory of all relevant lasers can be maintained. This will be used for University-level auditing and laser management. The Laser Inventory Form (LS-5) can be used for this purpose.