These ducts shall

D.5.1.1 These ducts shall be of any material having low flame spread characteristics which is type
approved 2.
D.5.1.2 On ships constructed on or after 1 July 2010, the ducts shall be made of heat resisting noncombustible
material, which may be faced internally and externally with membranes having low
flamespread characteristics and, in each case, a calorific value 3 not exceeding 45 MJ / m2 of their surface
area for the thickness used.
D.5.1.3 They may only be used at the end of the ventilation device.
D.5.1.4 They shall not be situated less than 600 mm, measured along the duct, from an opening in an
"A" or "B" class division including continuous "B" class ceilings.
D.5.2 Flexible bellows of combustible material may be used for connecting fans to the ducting in air
conditioning or fan rooms.
D.5.3 Ducts provided for the ventilation of machinery spaces of category A, galleys, vehicle spaces,
ro-ro cargo spaces or special category spaces shall not pass through accommodation spaces, service
spaces or control stations unless the ducts are either: