These distances are based primarily on hydrogen piping releases and resultant vapor clouds and jet flames based on pipe diameter and pressure. It’s important to note that many facilities have issues such as confinement and congestion, so it may be applicable to apply contemporary engineering models to assess risk.

NFPA 2 has provisions for the use of LH2, and there are many existing fueling stations that store and use liquid hydrogen. One challenge for the use of LH2 in stations with small footprints is the code required separation distances from exposures. NPFA 2 has updated the separation distances with a risk informed approach in the 2023 edition.

Another possibility for public fuel…

Regarding cylinders, it is not necessary to capture the fuse-backed devices which are on the cylinder itself. However, all other relief devices and vent valves must exhaust from a vent system designed in accordance with CGA G-5.5. Also, note that NFPA 2-7.1.17 requires compliance with CGA G-5.5 regardless of storage quantity when the vent system is servicing pressure relief devices. Cylinders…

The vent system for the excess hydrogen should be vented in accordance with NFPA 2 and CGA G-5.4 and G-5.5. The oxygen also must be vented safely and should be in accordance with NFPA and CGA G-4.4. 

Please be extremely cautious with compressing hydrogen. NEC/NFPA 70 and its Articles 500/505 address electrical equipment in flammable atmospheres. Please also consider the…

The British Standards Institute (BSI) has published BS ISO 22734:2019, a British nationalized version of the packaged water electrolyzer safety certification standard. This standard can be used by a Notified Body (BSI is one of many operating in the UK and in Europe) to certify electrolyzer safety to established norms for this equipment. This standard addresses safety of containerized hydrogen…

The regulations for electrical classification in Europe and a US jurisdiction such as California are significantly different and should not be assumed to be the same. Consultation with Authorities Having Jurisdiction or a Third- Party expert regarding the application of the US National Electric Code is advised. Some additional important points:

The HSP has concerns with the use of…

There are no specific code resources that specifically cover hydrogen liquefaction plants, but they must be built to the general building, electrical, machinery, piping, and mechanical codes for process plants. Codes such as NFPA 2, Hydrogen Technologies Code, for installation and emergency response may also be used for reference. It may also be beneficial to break down the requirements into…

Panel members have not encountered a device or area classification for ATEX approval within Canada. ATEX is a European Union directive and is not generally recognized within North American standards. The second link below references a UL similarity. https://news.nilfiskcfm.com/2017/03/atex-certification-applicable-north-america/;    https://www.ul.com/services/atex-certification-…

This production rate of hydrogen of about 96 kg/h is quite significant, which depending upon the application might require a significant amount of storage. There will be a need to determine how many kg the project wants to store from this production rate in order to determine how much hydrogen ground storage is needed. Since the project is in Europe, look for pressure vessel manufacturers that…

Hydrogen cylinders contain pure hydrogen unless they are specifically manufactured for and marked as a mixture. The purity grade is usually between 99.5% and 99.9999%. The balance is typically inert gases (such as nitrogen) with just ppm levels of other contaminants, but this can vary depending upon the production source. When emptied, the residual is still the same purity of hydrogen, just at…