Control areas are areas within buildings that are separated from the rest of the building by fire-rated construction. This creates compartments that will resist the spread of fire to the rest of the structure. Each of these compartments is treated as a separate storage area in regard to flammable liquids. These compartments, or fire areas, are known as 'control areas' because they are intended to control the spread of fire through the building. Commonly, control areas are wings of buildings, individual floors separated by stairwells and fire doors, or a portion of these.
If the storage limitations are exceeded, the fire classification of the building is deemed a 'hazardous occupancy,' and the resulting fire safety regulations that must be met are extensive and costly because few buildings are designed or built to these standards, and must be renovated.
Many buildings will consist of multiple control areas. To ensure that the control area limitations are not exceeded it is important to maintain a thorough and accurate inventory, and routinely assess the necessity of quantities stored.
The code limits for storage within each control area can be viewed here
For more information on the control areas within your building, and the limitations that might apply, contact your building administrator or department head.