This document specifies a test method for determining the fire resistance of smoke extraction ducts. It is applicable only to smoke extraction ducts that pass through another fire compartment from the fire compartment to be extracted in case of fire. It represents fire exposure of a fully developed fire. This method of test is only applicable to ventilation ducts with the following classification according to EN 13501-3: ?? fire from inside and outside i ? o; ?? applicable to a pressure difference up to 500 Pa; NOTE 1 Requires that the duct A test(s) has been preformed with an under-pressure of minimum 500 Pa. ?? with integrity (E) and insulation (I) criteria equal to or higher than the intended classification for the smoke extraction duct. NOTE 2 According to: EN 13501?C4:2009/A1:2009 Multi-compartment smoke extraction duct can only be classified as EI. For the purposes of the test described in this document@ the duct is referred to as duct C. This test method has been designed to cover both vertical and horizontal smoke extraction ducts. A vertical system need not be evaluated to this method provided that: ?? both horizontal (ho) and vertical (ve) classification according to EN 13501-3 has been obtained for the ventilation duct@ and ?? it has been tested in a horizontal orientation to this method. If the ventilation duct in practice is only used for vertical applications in smoke extraction systems@ only vertical (ve) classification is bound to be used and tested in a vertical orientation to this method according to EN 13501-3. This test method is suitable for ducts constructed from non-combustible materials (Euroclass A1 and A2). NOTE 3 Using combustible material could lead to an incorrect calculation of the leakage based on the oxygen measurement. E.g. galvanisation could lead to some negative effects for the measurements. It is applicable only to four sided ducts; one@ two and three sided ducts are not covered.