This document describes the basic requirements for the design and application of explosion suppression systems. This document also specifies test methods for evaluating the effectiveness and the scaling up of explosion suppression systems against defined explosions. This document covers:-general requirements for explosion suppression system parts;-evaluating the effectiveness of an explosion suppression system;-evaluating the scale up of an explosion suppression system to larger than tested volumes;-development and evaluation of design tools for explosion suppression systems;-installation, operation and maintenance instructions for an explosion suppression system.This document is applicable only to explosion suppression systems intended for the protection of closed, or essentially closed, enclosures in which an explosion could result as a consequence of ignition of an explosible mixture, e.g. dust-air, gas(vapour)-air, dust-gas(vapour)-air and mist-air.This document is not applicable for explosions of materials listed below, or for mixtures containing some of those materials:-unstable materials that are liable to dissociate;-explosive materials;-pyrotechnic materials;-pyrophoric materials.