A flame arrester (FA1) having an inlet (12) and an outlet (32), a housing (13, 23, 33) between the inlet (12) and outlet (32), one or more baffle plates (14, 34) and a flame arrester element (20) located within the housing (13, 23, 33). The inlet (12) has a maximum diametric dimension (D12). A first baffle plate (14) is located downstream of the inlet (12) and the flame arrester element (20) is located downstream of the first baffle plate (14). A second baffle plate (34) is located downstream of the flame arrester element (20) and upstream of the outlet (32). The baffle plates (14, 34) are secured to the inner wall of the housing (13, 23, 33) and each has an aperture (15, 35). The aperture (15) of the first baffle plate (14) has a minimum diametric dimension of at least 0.75D12.
