This European Standard describes the general requirements for explosion isolation systems. This standard specifies methods for evaluating the efficacy of the various explosion isolation systems, and methods for evaluating design tools for such explosion isolation systems when applying these in practice. This European Standard also sets out the criteria for alternative test methods and interpretation means to validate the efficacy of explosion isolations. It covers e. g.: a) general requirements for the explosion isolation components; b) evaluating the effectiveness of an explosion isolation system; c) evaluating design tools for explosion isolation systems; d) installation requirements for explosion isolation systems; e) maintenance requirements for explosion isolation systems. This European Standard is applicable only to the use of explosion isolation systems that are intended for avoiding explosion propagation between interconnected enclosures in which an explosion may result as a consequence of ignition of an explosive mixtures e. g., dust-air mixtures, gas-(vapour-)air mixtures, dust-, gas-(vapour-)air mixtures and mists. In general explosion isolation systems are not designed to prevent fire transmission. This standard is only applicable for explosions of chemicals, stable materials and mixtures of these (flame propagating at subsonic velocity). This standard is not applicable for explosions of materials listed below, or for mixtures containing some of those materials: a) unstable materials that are liable to dissociate; b) explosive materials; c) pyrotechnic materials. This standard does not cover flame arresters. For these devices refer to EN 12874.