Gives guidance on the design, selection and erection of electrical installations in areas where explosive gas atmospheres could occur. Applies to all permanent electrical installations within the scope of IEC 364-1. However, may be applied, where appropriate, to electrical installations with voltages higher than the upper limit of IEC 364-1, namely 1 000 V a.c. Wherever possible the recommendations given should also be applied to temporary electrical installations, such as experimental prototype or pilot industrial installations. This publication has the status of a technical report.