KANBrief 4/13

Laser safety: new limit values in standards present problems for occupational safety and health

Lasers are ubiquitous. They assure the utmost precision in machining, are used in spectroscopic methods in research, form part of medical diagnostic and therapeutic procedures, and are to be found in consumer electronics and DIY products. The problems associated with the current revision of the laser safety standard are described by Martin Brose of the BG ETEM (German Social Accident Insurance Institution for the energy, textile, electrical and media products sectors) and Dr Erik Romanus of the BAuA (Federal Institute for Occupational Safety and Health).

What hazards are associated with the use of laser technology?

Brose: In the past, hazards and accidents occurred primarily in laboratories, for example during research work, and during the manufacture and repair of high-performance (Class 4) lasers. However, the use of laser pointers by private individuals is now increasingly causing eye injuries and dazzle.

What codes are relevant to laser products?

Romanus: The safety of laser products operated at mains voltage is governed by the EU Lowvoltage Directive. Battery-powered laser products are governed by the EU General Product Safety Directive. These EU directives are transposed into national acts and regulations in the EU Member States. The EN 60825-1:2007 harmonized standard, "Safety of laser products", provides technical support for the essential requirements of the Low-voltage Directive in relation to laser safety. The standard describes safety requirements and a system for the classification of laser products.

Conversely, the safe use of laser products at workplaces is governed in EU Directive 2006/25/EC (of the European Parliament and of the Council on the minimum health and safety requirements regarding the exposure of workers to risks arising from physical agents (artificial optical radiation)). This directive sets out the occupational exposure limits for protection against laser radiation hazards. The limits found in both EN 60825-1:2007 and the 2006/25/EC directive are based upon the recommendations made by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) in 1996 (Health Physics. 71(5):804-819, 1996) and 2000 (Health Physics. 79(4):431-440, 2000).

The ICNIRP has now revised its exposure limit concept for laser radiation in consideration of recent scientific findings (Health Physics. 105(3):271-295, September 2013). This coincides with the availability of a new draft of EN 60825-1, which is already based upon this new limit value concept.

What impact do the new limit values have?

Brose: The ICNIRP's new recommendations for exposure limit values form the basis for the risk assessment of lasers in the current EN 60825-1 draft standard. In some cases however, they lie above or below the limit values of EU directive 2006/25/EC, which are still valid, and thus also those in the German OSH ordinance governing artificial optical radiation (OStrV).

According to the standard for example, some lasers currently assigned to the high 3B hazard class would in future fall within the lowest class (Class 1), and the product would thus no longer be subject to mandatory labelling. However, the exposure limit values of the 2006/25/EC directive may be exceeded when such laser products are used. This causes considerable problems for users, for example employers, schools and universities, since they are not informed of their possible statutory requirement to take protective measures.

The OSH representatives drew attention to this issue; the German mirror committee then rejected the draft standard. The OSH representatives call for the standard to be amended when it is adopted as a European standard, with the addition of clear statements that the manufacturer must provide corresponding indication in his user information should a possibility exist of the occupational exposure limits of directive 2006/25/EC being exceeded.

What would be a robust solution?

Romanus: Limit values are based not solely on scientific data on the biological effects of laser radiation, but also on an up-to-date evaluation of the socioeconomic risk and the practicality. Since the specification of limit values is a matter of government policy, it would fall to the European Commission to discuss whether and to what extent the ICNIRP's limit value concept updated in line with scientific findings is better suited to protecting workers against hazards presented by laser radiation. In my view, the Standing Advisory Committee on Safety and Health at Work, on which government bodies, trade unions and employers' associations of the Member States are represented, would be a suitable body to make preparations for this decision. This may then also necessitate updating of the annexes of directive 2006/25/EC.