NFPA 58-11: Liquefied Petroleum (LP) Gas Code, 2011 Edition

Enforced in most states and referenced by DOT, NFPA 58: Liquefied Petroleum Gas Code provides minimum safety requirements for all liquefied petroleum gas (propane) installations — from small cylinders installed at residences to large bulk storage facilities that can exceed 100,000 gallons. It includes minimum requirements for safe handling during LP-Gas transfer, including operator qualifications, maximum filling quantity in containers, and pre-transfer inspections to ensure containers are fit for continued service.
NFPA 58 also covers a number of safety requirements related to container construction; piping design; separation of containers from homes, stores, schools and other important buildings; and safe handling of liquefied petroleum gas during transfer between containers.