The international standard for laser processing machines is ISO 11553. This is implemented into a European normalised standard as EN12626. During 2005, this standard has been reissued as ISO 11553-1. The change of nomenclature is due to the initiation of development work for a standard for hand held laser processing devices, which will become Part 2 of the ISO 11553 family. Hence the original laser processing machine standard is to be Part 1 and thence renamed ISO 11553-1.

The main reason for the reissue, though, is to put right a major limitation that prevents this standard from being used when specifying a significant number of laser processing machines. When the standard was first published in 1996, the scope of the standard was limited to those machines which conformed to a Class 1 laser product classification (in accordance with IEC 60825-1). In other words, the standard could only be applied to those machines where the laser radiation was totally enclosed and access was totally prevented. Under these conditions a very large number of laser processing machines using CO 2 lasers as the primary laser source where not eligible as these machines are often not fully enclosed – for example open topped flat bed sheet laser cutting machines. These machines though not totally enclosed are completely safe when used as intended and can be assessed to be in compliance with the Machinery Directive and thus CE marked.

The revised standard has removed this limitation and allows the standard to be applied to a much wider range of laser processing machines. This is extremely valuable as the standard provides a complete set of requirements that addresses the wider range of hazards usually associated with a processing machine. With the Class 1 restriction removed, the standard can be applied to open topped machines or to machines where the guarding has been determined by risk assessment rather than assuming total enclosure is necessary.

The standard now requires the environment in which the machine is situated and operated to be specified together with degree of control that is exercised over persons utilising the machine or with access to it.

The location of the laser processing machine is now important. Three situations have been defined and the degree of protection to be provided is dependant on the type of location.

The first location considered is a location with “controlled access”. This is a location where the hazard is inaccessible except to authorised persons who have received adequate training in laser safety and servicing the systems involved. The second location considered is a location where the hazard is inaccessible to the public, but may be accessible to other observers or other untrained personnel who are kept from being exposed to the hazards of laser processing by barriers or other methods. Where the laser processing machine is to be used in either of the above two locations, the laser guarding may be determined by risk assessment methods, taking into account the personnel who may have access to the machine. It should be noted that the word “controlled” refers to access of people who are both authorised and trained in laser safety, whereas the word “restricted” refers to access areas where the public are not allowed but those with access are authorised to be there but may not be trained in laser safety and thus require to be provided with protection. During production, the possibility that people be exposed to levels of laser radiation exceeding the maximum permissible exposure (MPE) at the ocular exposure limits for 3 × 104 seconds exposure shall be eliminated. To satisfy this requirement, the following conditions shall be met.

• A Risk Assessment shall be performed. Unauthorized human access to a danger zone should be prevented by engineering measures as specified in IEC 60825-1 and ISO 12100-1 and ISO 12100-2.

• If access cannot be prevented, exposure above the ocular MPE shall be eliminated by use of engineering or administrative controls, including Personal Protective Equipment (PPE).

Locations that are both unlimited (i.e. uncontrolled) and unrestricted are those where the public may have access and thus total protection must be provided. In these cases the laser processing machine must meet the requirements of a Class 1 laser product.

Other requirements within the standard, which require consideration of all the other hazards associated with machine tools, fume extraction, the by-products of laser processing etc., remain unchanged.

The re-issue of the standard also presented an opportunity to bring the European EN standard into line with the ISO standard. Difficulties where presented when the main safety standard supporting the Machinery Directive had the nomenclature EN292. Within ISO this standard could only be issued as a Technical Note due to the references to the Machinery Directive. Work has been undertaken in the last few years to eliminate this problem which culminated in the issue of a totally revised ISO standard, namely ISO 12100-1 and ISO 12100-2 for the Safety of Machinery. The European standard EN292 was withdrawn in December of 2003 and immediately replaced with EN ISO 12100-1 and -2. This now allows other ISO standards and EN standards to be synchronised. The effect on the laser processing machine standard is that on publication of the latest version of ISO 11553-1 (discussed above), it allows the standard to be adopted by CEN as EN ISO 11553-1 and the CEN standard EN12626 will be withdrawn. This synchronisation will significantly benefit the rest of the world as now only one standard will be applicable in Europe and outside Europe.

The story has not yet been concluded as the end of 2003 saw the introduction of a revised Directive relating to noise in the workplace. This Directive places constraints on manufacturers of equipment and on employers using any equipment in the workplace. Thus the laser processing machine standard will have one more revision to include the requirements placed on manufacturers to meet the revised Noise Directive. Work is currently progressing to establish a set of requirements that meet the needs of the Directive but do not become too onerous on equipment manufacturers. During discussions with the European Commissioners’ Noise Consultant, there was definite danger that the standard would be overwhelmed by the noise requirements (specification, verification and documentation requirements) and that the noise requirements would dominate everything. Fortunately, other machine tool standards groups have been wrestling with this problem for the laser 15 years and their experience will benefit the laser processing machine standard. The revised standard will probably not appear until the end of 2006 to coincide with end of the transition period for application of the Noise Directive.