KAN Report 6
|Safety components - working basis for standardization, 08/1996, F. Kreutzkampf/F. Börner (333 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.
- Status review
- In the course of rationalisation, manufacturers of plant and machinery are making increasing use of suppliers of components and subsystems. If these components and subsystems have safety functions to perform, they must meet special safety requirements. EC directives take account of this fact and no longer govern plant and machinery alone, but have been extended to cover safety-related components.
- This study puts together EC directives according to Article 100 and 100a of the EC Treaty which formulate requirements for safety-related components. For each of these EC directives, the definitions of safety-related subsystems, requirements and conformity assessment processes are described and analysed for common features.
- The study lists the components mentioned in the collection of EC directives and those derived from the definitions. The status review of the relevant European standards or draft standards underlines the fact that standardisation activities have been commenced or completed for almost all components listed.
- The study provides the relevant German regulations, standards and sets of rules in which safety-related requirements and assessment criteria for components are described. It becomes clear that these cover a large proportion of the basic requirements which are mentioned in or can be derived from the EC directives.
Status review analysis
- Although various terms are selected in the EC directives for systems and subsystems with safety functions (e.g. part, component, device, safety component), a single definition can, according to the study, be derived in most cases. According to this definition, it must be possible for safety-related components to be put into use individually and to adopt a safety function in accordance with the directive's requirements.
- As far as a series of safety-related components is concerned, requirements are not to be found in independent component standards, but are integrated into product standards for specific application.
- Harmonised European Standards or draft standards differ considerably with regard to their scope, content and depth of requirements. For example, some standards and draft standards for safety components are kept very general and do not sufficiently complete the basic requirements of the EC Machinery Directive (see EN 418 "Emergency stop equipment" or prEN 1088 "Interlocking devices"). By contrast, detailed component and test standards are drawn up for other safety components which, in some cases, do more than just complete the basic requirements of the relevant EC directive in terms of content and depth of requirement (prEN 1760 "Pressure sensing mats" or prEN 50100 "Electro-sensitive protective devices").
- In general, the study complains that the passing of European standards and their harmonisation is, in many cases, hesitant. In addition, attention is drawn to the fact that appropriate standardisation projects for new technology are obviously lacking.
Proposal for Germany's standpoint
- The study proposes that a standard term for components, systems and subsystems with safety functions be created in the directives as a basis for European standardisation.
- Independent component standards or special clauses in product standards should be drawn up, on the basis of which a safety assessment can be made for the conformity declaration. This is especially important if safety-related components are put into use individually.
- The content of standards for components should be based on the basic safety and health requirements of the relevant EC directive and simply complete them.
- Priorities should be set in order to accelerate standardisation activities with significant safety content - with regard to taking up new standardisation projects as well as to the standardisation activities as such.
- If there is no Harmonised European Standard, European draft standards should be recommended and taken into account as the basis for a safety assessment.
The report provides a good overview of the status of standardisation in the field of safety-related components at the time the study was carried out. All directives relevant to the field of components were analysed and the applicable set of standards listed. Proposals for a national standpoint were derived from the clearly presented problem areas.
Concerning two aspects, KAN draws conclusions from the results of the study departing from the authors:
- The safety-related components in the individual directives cannot be summarised using a single term. For example, the term "safety components" as used in the Machinery Directive covers far less than the component terms of other directives.
- If there is no Harmonised European Standard, final drafts for prEN, whose acceptance can be considered a formality according to consultation at CEN level, should be recommended and taken into account as the basis for a safety assessment. This should not already apply to the stage of European draft standards.
- Need for action from the German Federal Ministry for Labour and Social Affairs (BMA)
- Terms such as component, device etc. are currently used in the various directives. The BMA is called upon to work towards clear terminology for safety-related components in future EC directives.
- In cases in which Harmonised European Standards have not yet been completed, the BMA is recommended to suggest that final drafts for prEN be recommended for a transitional period as a basis for assessment in individual cases so that they can be consulted for the conformity declaration. This should be limited to those final draft standards for which consultation at CEN level has shown that acceptance can be considered a formality.
Need for DIN to take action
- The term "safety component" should be included as a descriptor in the register of headwords for standardisation.
- Via DIN, KAN appeals to the Technical Committees of CEN/CENELEC to draw up clauses in the product standards which can be quoted and on whose basis a conformity declaration or test certification for components can take place. If components cannot be assigned to a single product and are not dealt with in the product-specific standard, a limited number of individual standards should be drawn up.
- Existing standards and those in preparation vary considerably with regard to scope and depth of requirement. The Technical Committees of CEN/CENELEC are therefore requested via DIN to mark clearly the product requirements formulated in the safety component standards which serve to complete the fundamental requirements of an EC directive. This can, for example, be done with the help of an informative annex which states the relevant EC directive in addition to the applicable requirements.
- DIN is requested to initiate a list of priorities with regard to safety component standardisation. This is aimed at making sure that standardisation activities with significant safety content can be given priority treatment. The KAN secretariat is instructed to find out what the groups represented in KAN think about this, to evaluate their opinions and present them to DIN.