To limit the probability of reduced holding capacity or unavailability of the containment in an emergency, which could lead to the escape of liquid outside of the spill containment, which could lead to the ignition of vapour from a nearby ignition source, which could lead to harm to persons.
To limit the probability of delays or ineffectiveness in conducting firefighting or spill control operations, which could lead to the spread of fire beyond the point of fire origin, which could lead to harm to persons.
To limit the probability of creating a fire hazard near the storage tank, which could lead to a fire exposure to the tank, which could lead to the escape and spread of liquid, which could lead to the ignition of vapour from a nearby ignition source, which could lead to harm to persons.