This information is from NFPA Pamphlet 58.
Chapter 8 Storage of Cylinders Awaiting Use, Resale, or Exchange
8.1.1 The provisions of this chapter apply to the storage of cylinders of 1000 lb (454 kg) water capacity or less, whether filled, partially filled, or empty as follows: (1) At consumer sites or dispensing stations, where not connected for use (2) In storage for resale or exchange by dealer or reseller
8.1.2 This chapter does not apply to new or unused cylinders.
8.1.3 This chapter does not apply to cylinders stored at bulk plants.
8.2 General Provisions.
8.2.1 General Location of Cylinders.
22.214.171.124 Cylinders in storage shall be located to minimize exposure to excessive temperature rises, physical damage, or tampering.
126.96.36.199 Cylinders in storage having individual water capacity greater than 2.7 lb (1.1 kg) [nominal 1 lb (0.45 kg) LPGas capacity] shall be positioned so that the pressure relief valve is in direct communication with the vapor space of the cylinder.
188.8.131.52 Cylinders stored in buildings in accordance with Section 8.3 shall not be located near exits, stairways, or in areas normally used, or intended to be used, for the safe egress of occupants.
184.108.40.206 If empty cylinders that have been in LPGas service are stored indoors, they shall be considered as full cylinders for the purposes of determining the maximum quantities of LPGas permitted by 8.3.1, 220.127.116.11, and 18.104.22.168.
22.214.171.124 Cylinders shall not be stored on roofs.
8.2.2 Protection of Valves on Cylinders in Storage.
126.96.36.199 Cylinder valves shall be protected as required by188.8.131.52 and 184.108.40.206.
220.127.116.11 Screw on type caps or collars shall be in place on all cylinders stored, regardless of whether they are full, partially full, or empty, and cylinder outlet valves shall be closed.
18.104.22.168 Valve outlets on cylinders less than 108 lb (49 kg) water capacity [nominal 45 lb (20 kg) propane capacity] shall be plugged, capped, or sealed in accordance with22.214.171.124.
8.3 Storage Within Buildings.
8.3.2 Storage Within Buildings Frequented by the Public and in Residential Occupancies.
126.96.36.199 The quantity of LPGas in cylinders stored or displayed shall not exceed 200 lb (91kg) in buildings frequented by the public.
188.8.131.52 The cylinders shall not exceed a water capacity of 2.7 lb (1.1 kg) [nominal 1 lb (0.45 kg) LPGas].
184.108.40.206 Storage in restaurants and at food service locations of 10 oz (283 g) butane non-refillable containers shall be limited to no more than 24 containers and an additional twenty four 10 oz (283 g) butane non-refillable containers stored in another location within the building where constructed with at least a 2hour fire wall protection.
8.3.3 Storage Within Buildings Not Frequented by the Public.
220.127.116.11 The maximum quantity of LPGas allowed in one storage location shall not exceed 735 lb (334 kg) water capacity [nominal 300 lb (136 kg) LPGas capacity].
18.104.22.168 Where additional storage locations are required on the same floor within the same building, they shall be separated by a minimum of 300 ft (91.4 m).
22.214.171.124 Storage beyond the limitations described in126.96.36.199 shall comply with8.3.4.
188.8.131.52 Cylinders carried as part of the service equipment on highway mobile vehicles shall not be part of the total storage capacity in the requirements of184.108.40.206, where such vehicles are stored in private garages and carry no more than three cylinders with a total aggregate capacity per vehicle not exceeding 100 lb (45.4 kg) of LPGas.
220.127.116.11 Cylinder valves shall be closed when not in use.
8.3.4 Storage Within Special Buildings or Rooms.
18.104.22.168 The maximum quantity of LPGas stored in special buildings or rooms shall be 10,000 lb (4540 kg).
22.214.171.124 Special buildings or rooms for storing LPGas cylinders shall not be located where the buildings or rooms adjoin the line of property occupied by schools, churches, hospitals, athletic fields, or other points of public gathering.
126.96.36.199 The construction of all such special buildings and rooms shall comply with Chapter 10 and the following: (1) Vents to the outside only shall be provided at both the top and bottom of the building and shall be located at least 5 ft (1.5 m) from any building opening. (2) The entire area shall be classified for purposes of ignition source control in accordance with Section6.20.
8.3.5 Storage Within Residential Buildings. Storage of cylinders within a residential building, including the basement or any storage area in a common basement storage area in multiplefamily buildings and attached garages, shall be limited to cylinders each with a maximum water capacity of 2.7 lb (1.2 kg) and shall not exceed 5.4 lb (2.4 kg) aggregate water capacity for smaller cylinders per each living space unit.
8.4 Storage Outside of Buildings.
8.4.1* Location of Storage Outside of Buildings.
188.8.131.52 Storage outside of buildings for cylinders awaiting use, resale, or part of a cylinder exchange point shall be located as follows:
(1) At least 5 ft (1.5 m) from any doorway or opening in a building frequented by the public where occupants have at least two means of egress as defined byNFPA101, Life Safety Code
(2) At least 10 ft (3 m) from any doorway or opening in a building or sections of a building that has only one means of egress
(3) At least 20 ft (6.1 m) from any automotive service station fuel dispenser 184.108.40.206 Distances from cylinders in storage outside buildings shall be in accordance with Table 220.127.116.11 with respect to the following: (1) Nearest important building or group of buildings (2) Line of adjoining property that can be built upon (3) Busy thoroughfares or sidewalks (4) Line of adjoining property occupied by schools, churches, hospitals, athletic fields, or other points of public gathering (5) Dispensing station
18.104.22.168 Cylinders in the filling process shall not be considered to be in storage.
8.4.2 Protection of Cylinders.
22.214.171.124 Cylinders at a location open to the public shall be protected by either of the following:
(1) An enclosure in accordance with126.96.36.199
(2) A lockable ventilated metal locker or rack that prevents tampering with valves and pilferage of the cylinders
188.8.131.52* Protection against vehicle impact shall be provided in accordance with good engineering practice where vehicle traffic is expected at the location.
8.4.3 Alternate Location and Protection of Storage. Where the provisions of8.4.1 and 184.108.40.206 are impractical at construction sites or at buildings or structures undergoing major renovation or repairs, alternate storage of cylinders shall be acceptable to the authority having jurisdiction.
8.5* Fire Protection.
8.5.1 Storage locations, where the aggregate quantity of propane stored is in excess of 720 lb (327 kg), shall be provided with at least one approved portable fire extinguisher having a minimum capacity of 18 lb (9.2 kg) dry chemical with B:C rating.
8.5.2 The required fire extinguisher shall be located no more than 50 ft (15 m) from the storage location. Where fire extinguishers have more than one letter classification, they can be considered to satisfy the requirements of each letter class.