To supersede the requirement for a minimum 1 h rated fire separation as stated in Sentence 9.10.10.3.(1), which would otherwise apply only in unsprinklered floor areas, and make it applicable in sprinklered floor areas as well, on the basis that rooms with such storage pose an increased fire risk.
To limit the probability that fire will spread from a storage room to other parts of the building, which could lead to damage to the building.
To limit the probability that a fire originating in a location outside a storage room will spread into the storage room, which could lead to the further spread of fire, which could lead to damage to the building.