IEC 60079-10-2:2009 is concerned with the identification and classification of areas where explosive dust atmospheres and combustible dust layers are present, in order to permit the proper assessment of ignition sources in such areas. The principles of this standard can also be followed when combustible fibres or flyings may cause a hazard. This standard is intended to be applied where there can be a risk due to the presence of explosive dust atmospheres or combustible dust layers under normal atmospheric conditions. This first edition of IEC 60079-10-2 cancels and replaces the first edition of IEC 61241-10 published in 2004. The significant technical changes with respect to IEC 61241-10 are: - the hazards presented by dust have been clarified; - dust groups have been introduced; - Annex D explaining Equipment Protection Levels (EPLs) has been introduced; - 1 m of usual extent of zone 22 beyond zone 21 has been expanded to 3 m.