To limit the probability of restricted access to tanks, valves and ancillary equipment in the containment space by employees for normal operation, maintenance or inspection, which could lead to defects or liquid escape going unnoticed, 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 restricted access to tanks, valves and ancillary equipment in the containment space by emergency responders, which could lead to delays or impediment of their operations, which could lead to the spread of fire beyond the point of fire origin, which could lead to harm to persons.