IEC 60079-10-1:2008 is concerned with the classification of areas where flammable gas or vapour or mist hazards may arise and may then be used as a basis to support the proper selection and installation of equipment for use in a hazardous area. It is intended to be applied where there may be an ignition hazard due to the presence of flammable gas or vapour, mixed with air under normal atmospheric conditions, but it does not apply to a) mines susceptible to firedamp; b) the processing and manufacture of explosives; c) areas where a hazard may arise due to the presence of combustible dusts or fibres; d) catastrophic failures which are beyond the concept of abnormality; e) rommos used for medial purposes; f) domestic premises. This first edition of IEC 60079-10-1 cancels and replaces the fourth edition of IEC 60079-10, published in 2002, and constitutes a technical revision. The significant technical changes with respect to the previous edition are: - introduction of Annex D which deals with explosion hazard from flammable mists generated by the release under pressure of high flash point liquids; - introduction of Clause A.3 (release rate) which gives thermodynamic equations for release rate with a number of examples for estimating release rate of fluids and gases.