IEC 60079-29-2:2015 gives guidance on, and recommended practice for, the selection, installation, safe use and maintenance of electrically operated Group II equipment intended for use in industrial and commercial safety applications and Group I equipment in underground coal mines for the detection and measurement of flammable gases complying with the requirements of IEC 60079-29-1 or IEC 60079-29-4. This second edition cancels and replaces the first edition published in 2007. This edition constitutes a technical revision. Please refer to the Foreword of the document for a listing of the changes from the previous edition. Keywords: gas detectors, flammable gases, vapours