IEC 60079-18:2014+A1:2017 gives the specific requirements for the construction, testing and marking of electrical equipment, parts of electrical equipment and Ex components with the type of protection encapsulation "m" intended for use in explosive gas atmospheres or explosive dust atmospheres. This part applies only for encapsulated electrical equipment, encapsulated parts of electrical equipment and encapsulat ed Ex components (hereinafter always referred to as "m" equipment) where the rated voltage does not exceed 11 kV. The application of electrical equipment in atmospheres, which may contain explosive gas as well as combustible dust simultaneously, may require additional protective measures. This standard does not apply to dusts of explosives, which do not require atmospheric oxygen for combustion, or to pyrophoric substances. This standard does not take account of any risk due to an emission of flammable or toxic gas from the dust. This standard supplements and modifies the general requirements of IEC 60079-0. Where a requirement of this standard conflicts with a requirement of IEC 60079-0, the requirement of this standard takes precedence. This fourth edition cancels and replaces the third edition of IEC 60079-18:2009, and constitutes a technical revision. Please refer to the foreword of the document for a listing of the technical changes with respect to the previous edition.This publication is to be read in conjunction with IEC 60079-0:2011. This consolidated version consists of the fourth edition (2014) and its amendment 1 (2017). Therefore, no need to order amendment in addition to this publication.Keywords: encapsulation "m", explosive gas atmospheres, explosive dust atmospheres