Standards Development

Scope

This part of ISO/IEC 80079 provides guidance on classification of gases and vapours. It specifies a test method intended for the measurement of the maximum experimental safe gaps (MESG) for gas-air mixtures or vapour-air mixtures under normal conditions of temperature and pressure (20 °C, 101,3 kPa) so as to allow the selection of an appropriate group of equipment. This document also specifies a test method intended for use in the determination of the auto-ignition temperature (AIT) of a vapour-air mixture or gas-air mixture at atmospheric pressure, so as to allow the selection of an appropriate temperature class of equipment.This part of the ISO/IEC 80079 specifies a method for the determination of explosion characteristics of flammable gases and vapours with air in an enclosed space.   It gives the criteria by which results obtained using other test procedures can be correlated to yield explosion characteristics as determined by the method specified in this part of ISO/IEC 80079.Values of chemical properties of materials are provided to assist in the selection of equipment to be used in hazardous areas. Further data may be added as the results of validated tests become available.The materials and the characteristics included in a table (see Annex B) have been selected with particular reference to the use of equipment in hazardous areas. The data in this document have been taken from a number of references which are given in the bibliography.These methods for determining the MESG or the AIT may also be used for gas-air-inert mixtures or vapour-air-inert mixtures. However, data on air-inert mixtures are not tabulated.