Standards Development

Scope

This document establishes basic principles to support understanding for users at all levels on the topic of equipment for explosive atmospheres. This includes an overview of the methods for the identification and assessment of hazardous situations which co uld lead to an explosion, and the design, construction, inspection and maintenance measures appropriate to achieve the required level of safety.

This document provides an outline of the structure of the standards prepared by IEC/TC 31 for correct application of the IEC 60079 and ISO/IEC 80079 series.

This document addresses the various elements in the lifecycle of equipment used in an installation involving explosive atmospheres, primarily through reference to other parts of the IEC 60079 and the ISO/IEC 80079 series. This document is also intended to resolve application details that are not currently well defined for smaller appliance type applications. 

Excluded from the work of IEC TC 31 and this document are hazards resulting from explosives.

Information in this document is also applicable where the requirements of other parts of the IEC 60079 and ISO/IEC 80079 series do not apply. This document and the associated standards in the IEC 60079 series, do not address compliance for other aspects of electrical safety.

This document, and the associated standards in the IEC 60079 series only supplement other aspects of electrical safety. IEC 60079-101 is a BASIC SAFETY PUBLICATION focussing on the prevention and mitigation of explosions due to flammable gas, flammable vapour, or combustible dusts. It is primarily intended for use by technical committees in the preparation of SAFETY publications in accordance with the principles laid down in IEC Guide 104, Guide 108 and lSO/lEC Guide 51.

One of the responsibilities of a TC is, wherever applicable, to make use of BSPs in the preparation of its publications.

Purpose

The document has been proposed by IEC TC 31 as part of the objective for IEC TC 31 to be assigned a Horizontal Safety Function related to explosive atmospheres. IEC TC 31 has consulted with ACOS (the IEC Advisory Committee on Safety) to request to be assig ned a Horizontal Safety Function and to develop this NP draft for an associated Basic Safety Publication in accordance with IEC guide 108.

The standards produced by TC 31 span many aspects of explosion safety and generally supplement other safety standards rather than covering all safety aspects of a specific group of products. TC 31 documents are used by other technical committees and manufa cturers when developing the technical requirements for many products related to explosive atmospheres. This is leading to an increase in the references to the standards prepared by TC 31 in product and installation standards developed by other committees.

It is TC 31 experience with explosion protection that there is general difficulty with other standards committees understanding all the aspects of the work of TC 31. This has led to errors in referencing, technical inconsistencies in approach and difficult ies in establishing solutions in the drafting of other IEC standards. While TC 31 has liaisons to other IEC and ISO committees to try and support resolutions on such aspects it is anticipated that the number of liaisons and effort in resolving relationship s could increase in the future.

In addition, the IEC 60079 and ISO/IEC 80079 series cover many elements and details related to explosion safety. However, the inter-relationship of the standards is not defined in a single publication and nor are the basic principles. Users of the series must work their way around references in a number of documents to establish links and try to understand core principles by dissecting technical details spanning a number of standards. Important principles and details are sometimes only mentioned on one doc ument and that one document might not be known to the user of other TC 31 standards. As the number of standards continues to grow these problems are exacerbated.

The objectives of the BSP include:

• Provide an outline of basic principles to ensure consistent approaches between committees

• Support understanding for users at all levels

• To assist with interfacing to other ISO and IEC committee for coordination of works and relationships related to hazardous areas, for example development of hydrogen standards

• Provide a 'road map' and entry point to the standards prepared by IEC TC 31 to promote correct referencing of TC 31 standards

• To resolve application details that are not currently well defined for smaller appliance type applications

• To ensure terminology is consistently applied between standards

The suite of standards prepared by TC 31 has been continually expanding to cover more and more elements related to explosion safety. In recent years this has included the development of not only IEC standards but also ISO standards with several existing IS O standards being transferred into the work of TC 31 under SC 31M.This proposed BSP would then be of interest to both ISO and IEC committees as a Horizontal Document.