KAN Report 16

	Standardization in the field of work with display screen equipment, 12/1997, P. Schäfer/A. u. G. Çakir (771 KB)
Bookmarks in the pdf file link directly to the individual chapters. In the list of bookmarks, all sections available in English and French are highlighted in colour.

Summary

Fundamental principles

Display Screen Equipment Directive 90/270/EEC is the 5th individual directive for the implementation of the Framework Directive on Occupational Health and Safety (89/391/EEC). It regulates the rights and obligations of employers and employees in the field of work with display screen equipment and is therefore a directive under Art. 118a of the EC Treaty. The directive was transposed into national law in December 1996 by the "Display Screen Equipment Regulation".

Although the Display Screen Equipment Directive is a directive under Art. 118a of the EC Treaty, the annexe to the directive contains minimum regulations concerning the technical nature of the visual display unit and work equipment. A specific directive under Art. 100a of the EC Treaty on display screen equipment, which would be responsible for setting product requirements at a binding protection level, does not exist. A mandate for the preparation of standards to supplement the Display Screen Equipment Directive was not issued by the EU Commission.

The majority of standards on work with display screen equipment is drawn up at international level in ISO/TC 159 "Ergonomics" under the topic of "Ergonomic requirements for office work using display screen equipment" and adopted into the European set of standards in accordance with the Vienna Agreement. Understandably, European directives are not explicitly observed when drawing up international standards. Despite the fact that there is no legal basis, these standards are, however, considered by the public as to support to the directive.

The study examined to what extent

• there is a connection between Directive 90/270/EEC and standards on work with display screen equipment;
• standards are restricted to the formulation of requirements concerning the nature of a product or regulate use;
• standardization reveals deficits for German occupational health and safety;
• further standardization would be useful.

In addition, possible strategies for improving the content and structure of standardization in the field of work with display screen equipment were also developed during the study.

 

Directive 90/270/EEC

The minimum regulations in the annexe to the Display Screen Equipment Directive are formulated not only as requirements concerning the nature of the product, but also in certain cases as general protection objectives. This is intended to leave scope for innovations. Various measures are necessary in order to satisfy these requirements:

• making available products which meet requirements
• regulations on use
• combination of both measures.

This combination of the safety and health of workers at work and product requirements in one directive makes it clear that separation into two directives,

• one under Article 100a of the EC Treaty which regulates the nature of the product and is supplemented by mandated standards and
• one under Article 118a of the EC Treaty which regulates use and is supplemented by national regulations,

would have made implementation easier.

 

Standards

The search for standards in the field of visual display units using the PERINORM database has revealed that it is difficult to determine the extent of both existing standards on this subject and those still being processed (e.g. it is difficult to find standards documents without knowing the exact descriptors; the PERINORM database contains incorrect information on the mandating of the EN ISO 9241 series of standards).

Nevertheless it is clear that the ISO 9241 series of standards and draft standards ("Ergonomic requirements for office work with visual display terminals") are the most important standards on work with display screen equipment. These are adopted as European standards DIN EN ISO 9241; at national level in Germany they are to replace the DIN 66234 series of standards.

 

Connection between standards and Directive 90/270/EEC

Binding national regulations subject to the political decision-making process rather than European standards are intended to supplement a directive under Article 118a of the EC Treaty.

Accordingly there is no standardization mandate from the EU Commission which makes a legal connection between standards on work with display screen equipment and EU Directives 89/391/EEC and 90/270/EEC. There is, however, a general mandate from Directorate General XIII of the EU Commission to CEN/TC 122 "Ergonomics" for the area of Display Screen Equipment Directive 90/270/EEC. This mandate, which existed before the Display Screen Equipment Directive, commissions the preparation of standards concerning information technology and telecommunications in the field of ergonomics. These mandated standards should have served as a basis for the preparation of the directive on work with display screen equipment. However, instead of separate European standards, ISO 9241 Part 1-4 was adopted as European standard EN ISO 9241 and can be consulted for this purpose. However, these standards only became valid standards after the Display Screen Equipment Directive had been passed.

No legal connection with standards was made when the Display Screen Equipment Directive was passed. In the future therefore every standard in the EN ISO 9241 series should refer to the fact that standards - which would usually serve to supplement requirements concerning the nature of a product - cannot be considered as to support the Display Screen Equipment Directive so that the manufacturer is not in a position to provide an attestation of conformity.

The subsequent mandating of standards series ISO 9241 Parts 5 - 17 is being considered at European level; a decision is yet to be made. The contents of standards which, from the point of view of the organization in charge of the project, would be suitable for supplementing individual requirements specified in the annexe to the directive, are listed in the study in a table.

 

Directive, standards and the German Consensus Statement

The requirements formulated in the annexe to Directive 90/270/EEC refer both to the nature of the product and to regulations on use. Due to their connection with Art. 118a of the EC Treaty, both make minimum requirements concerning occupational health and safety which can be exceeded at national level. At the same time, as far as requirements concerning the nature of a product are concerned, higher requirements may not be set at national level as this would create trade barriers in the single European market. Since certain regulations on use are directly linked to the nature of a product, higher requirements cannot be made at national level without erecting trade barriers.

This means that Germany cannot make use throughout of the right to set higher requirements than the minimum requirements when applying a directive under Art. 118a of the EC Treaty. Therefore, the minimum requirements laid down in the standards actually become the upper limits for requirements.

Due to the national 1:1 conversion of the Display Screen Equipment Directive into the Display Screen Equipment Regulation, however, higher requirements have not been set in Germany.

The DIN EN ISO 9241 series of standards contradicts the German Consensus Statement and the EU Memorandum on the role of standardization in connection with Art. 118a of the EC Treaty with regard to the following points:

• For certain individual parameters, minimum requirements are set which are below current German occupational health and safety requirements and the state of the art.
• Requirements concerning the nature of a product are linked to regulations on use.
• Measuring regulations, which could assist the comparability of a certain occupational health and safety level, are, however, lacking.

 

Shortcomings in standardization and their effects

The study, during which the individual parts of ISO 9241 and ISO 11064 "Ergonomic design of control centres" and ISO 13406 "Ergonomic requirements for visual display units based on flat panels" were examined in detail, revealed standardization deficiencies at several levels:

• Procedural deficiencies as regards the preparation of standards with effect on the quality of standards
  - Procedural deficiencies: Standardization is the task of various standards bodies which do not generally coordinate their work. It has not yet been possible even within ISO/TC 159 to structurally reflect the connections which exist in terms of content between the standards of the ISO 9241 series. This results in:
  - Deficiencies as regards content: Different standards specify different values for the minimum size of characters on the screen; the individual parts of standards ISO 9241 each contain their own definitions; the central terms of ISO 9241 "display screen equipment" and "office work" are not defined; parts 10-17 of ISO 9241 only contain recommendations and no requirements.
  - Problems of understanding: Certain contents of standards are difficult even for experts to understand.
  
  
• Structural deficiencies of standards
  Standards ISO 9241 do not reveal any hierarchical structure similar to, for example, the A, B and C structure in the field of machinery safety. A subdivision of this kind would improve clarity for users and facilitate application.
  
  
• Inadequate reference to human criteria
  As far as occupational health and safety is concerned, the fact that the standards series ISO 9241 Part 12 - 17 does not take human criteria (i.e. the aspects of work which are important for the workers) sufficiently into account, is of extreme importance. These standards make no reference to the stress and strain to which people are exposed and do not contain normative reference to the basic standard of the ergonomic design of work systems (ISO 6385).

These deficiencies lead to problems concerning the application of standards and to a reduction in the level of occupational health and safety in certain areas compared with the current status (e.g. on keyboards, light writing on dark key tops is to be permitted again after more than 10 years).

 

Summary

To sum up, it has been established that the main problems originate in the EC Display Screen Equipment Directive which, as a directive under Art. 118a of the EC Treaty, should regulate occupational health and safety. In accordance with the EU Memorandum on the role of standardization, product requirements, such as those contained in the annexe to this directive, should not be part of a directive of this kind. However, the report reveals that in reality, regulations on use are linked to the nature of products. The ISO 9241 standards series was not examined by the CEN consultant to make sure that it conformed with the directive before it was adopted in accordance with the Vienna Agreement.

The measures taken to implement the Display Screen Equipment Regulation must take account of the state of the art, occupational medicine, hygiene and other findings of ergonomic analysis; standards can also be consulted for this purpose.

Due to the existing situation, the user currently has no means of furnishing reliable proof of the fact that he satisfies the minimum requirements of the Display Screen Equipment Directive, i.e. conformity tests are not possible. Moreover, the manufacturer is also unable to provide attestation of conformity which is frequently requested by users.

As before, it is possible to fall back on the standards for the practical implementation of conformity tests.

The study reveals ways of how formal deficiencies, e.g. no connection between directive and standards, could be eliminated.

 

KAN's recommendations

Overall assessment

The report provides a good overview of the status of standardization in the field of work with display screen equipment at the time of the study. The list of individual standards and their deficiencies offers a practical approach to developing possible improvements.

KAN is of the opinion that standardization on work with display screen equipment must be observed critically. Problems can be attributed in part to the fact that in this case product requirements are linked to a directive under Article 118a of the EC Treaty and, in addition, that the main standards on work with display screen equipment are prepared at ISO level.

KAN is to take up the strategies developed in the study aimed at solving the above problems with the aim of safeguarding national occupational health and safety interests.

 

Need for action from DIN

1. DIN is requested to pass the study on to the German reflecting committee with the aim of eliminating the deficiencies of standards in terms of content and structure.

 

Need for action from KAN

2. The structuring of standardization against the background of European legislation (100a/118a) must be examined. The results of this analysis must then be discussed with a KAN working group.