In addition to CGA Pamphlet P-1 requirements, OSHA says at 1910.110(f)(4)(i), “Storage within buildings not frequented by the public (such as industrial buildings),” that the quantity of LP-Gas stored cannot exceed 300 pounds (approximately 2,550 cubic feet in vapor form) except as provided in subparagraph (5), which requires the construction and use of special buildings or rooms for larger quantities. This requirement limits the inside storage of propane tanks to a maximum of about four average-sized forklift fuel cylinders. Do not count those connected for use.