We had to comply with the following codes: Mainly, the 2003 International Fuel Gas Code, chapter 7 (Gaseous Hydrogen Systems); see also the 2003 International Fire Code, chapter 35 (Flammable Gases) and Chapter 22, Section 2209 (Hydrogen Motor Fuel-Dispensing and Generation Facilities). There is now a 2006 Fuel Gas Code. These Codes and the NEC below are available for purchase online (at for example techstreet.com), or from your local Building Department.
We contacted our county Building Department early on, to be sure that there were no surprises for anyone. We had already gathered some code information. We asked the Building Department what kind of permit they recommended for the hydrogen plumbing and what particular codes they wished us to follow. Because hydrogen is unfamiliar, there is conceivably a risk that local authorities might be overly cautious and make demands beyond those specified in the codes. We did not encounter this. Though the Department personnel had not dealt with hydrogen before, they quickly researched which standards applied and sent us the above codes. They recommended a mechanical permit, as for a propane installation. At the inspection they simply enforced the given code rigorously. In sum, we had a very smooth permitting experience.
The electric portion of the installation needed a separate permit and adheres to the NEC (National Electric Code). Note that electric and hydrogen permits are not a problem: Codes and inspectors are your friends. A legal and skookum system (like ours) can be installed almost anywhere.
For the inspection we pressure-tested the piping to 300 psi (150% of max) for 15 minutes. Below are additional code details (see also Storage Tank).