What guidance can be given regarding application of NFPA 2/55 code versus regulatory requirements given in OSHA 1910.103?
NFPA 2 Annex G provides a summary of the conflicts with 29 CFR 1910.103. This is language that has been in NFPA 55 for several cycles as this conflict has existed for many years. The requirements in the Federal Regulations were established in the early 1970s. Since that time, OSHA has not had sufficient resources to update the applicable provisions.
The primary difference between OSHA and NFPA requirements is the separation distances for bulk hydrogen storage systems. The separation distances were changed by NFPA several years ago based on scientific analysis of leak data. When evaluating installations involving CFR referenced standards such as the ASME Boiler and Pressure Vessel Code, OSHA inspectors are taught to accept compliance with later editions of the standards as meeting the requirements of the regulation. The same may be true for the differences between OSHA 49 CFR 1910.103 and NFPA 2.
See attached response from OSHA on the general topic of NFPA codes/standards.