This document specifies the requirements for the construction and testing of flow restricting enclosures for non-electrical equipment intended for use in potentially explosive atmospheres if the atmosphere outside the enclosure becomes explosive rarely and for short durations only.

This document supplements the requirements in EN 13463‑1 the contents of which apply in full to equipment constructed in accordance with this document.

Equipment complying with this standard meets the requirements of Group II - Category 3 equipment. The type of ignition protection described in this standard is unsuitable for use in combination with another type of protection to produce equipment of any other category than category 3.