Ammonia Refrigerant
Ammonia (Type B2) Refrigerant, Unrestricted Charge Category III Occupancy
Most refrigerated buildings are classified as 'Class 7b' this classification is determined by the purpose for which it is designed, constructed or adapted to be used.
A Class 7b building is one used for storage, or display of goods or produce for sale by wholesale'. a plant or machinery room must have the same classification as the part of the building in which it is situated.