Fire-extinguishing Arrangements in Machinery Spaces requirements:

There are to be at least two portable foam extinguishers or equivalent in each firing space in each boiler room and in each space in which a part of the oil fuel installation is situated. There is to be not less than one approved foam-type extinguisher of at least 135 l capacity or equivalent in each boiler room. These extinguishers are to be provided with hoses on reels suitable for reaching any part of the boiler room. In the case of domestic boilers of less than 175 kW, or boilers protected by fixed water-based local application fire-extinguishing systems as required by 10.5.5 where deemed appropriate by the Society, an approved foam-type extinguisher of at least 135 l capacity is not required.