Most common odorants will contaminate fuel cells. Additionally, hydrogen's small molecule and high buoyancy make it challenging to find a compatible odorant. Research is being conducted on fuel cell compatible odorants, but there are none currently in use. Like liquefied natural gas, liquid hydrogen also can’t be odorized due to its cryogenic temperature.

Hydrogen has been used as a fuel to operate cars, buses, trucks, submarines, aircraft, forklifts, trains and virtually every type of mobile equipment. Each has special considerations which often drive specific requirements for that vehicle type. For example, higher g-loadings of rail operations and operations within tunnels are a couple considerations, but there are no significant barriers…

All systems must be designed for the applicable operating parameters such as pressure, temperature,
and flow. The sub-cooled liquid hydrogen (sLH2) approach for fueling is comparable to other processes
commonly used to handle cryogenic liquids in the industrial gas industry where remaining gas is
condensed during the fill operation. These processes often operate above the critical…

Detection systems are nearly always installed but the system design and installation details of detection equipment are up to the manufacturer. Standards are being developed for this market.

Hydrogen flames can be nearly invisible in daylight, especially at low flowrates. The concentration of hydrogen does not have much effect on the color of the flame. Many hydrogen incidents or fires will have a bright orange hue, or even yellow flames. The color is primarily caused by contaminants that is either naturally in the air in certain environments, swept into the air during the release…

Yes, small flowrate vents may be invisible, particularly in daylight. Sometimes it may still be possible to see heat striations in the air from the heat generated by the fire, but it can be difficult to discern at low flowrates. 

The Hydrogen Safety Panel is not aware of any detailed guidelines or requirements. There are general requirements for personal protective equipment (PPE) in relevant codes and standards, but these often defer to the manufacturers requirements or a material safety data sheet (MSDS) for specifics. Ultimately, PPE selection is a matter between the employer and the employee and may need to…

Researchers from Sandia National Laboratories have conducted extensive research on these topics. They have reviewed the current literature, identified knowledge gaps in alternate fuel vehicles and tunnel safety, and developed a generalizable framework to assess tunnel safety for a diverse range of alternate fuel vehicles. Supported by…

The “Hydrogen Ready Appliances Assessment Report” published by the Northwest Energy Efficiency Alliance (NEEA) in February, 2023, is one of the most recent studies on this topic.  Several key items from the report pertaining to this question include the following:

1.    “There appears to be growing consensus that blends of up to 20% or perhaps even 30% are…

The UN ECE R134 regulation is a good requirement to follow as it copies the language in the UN GTR #13 regulation. The updated version of this UN document (UN GTR #13 Phase 2) is currently in approval review at the GRSP in Geneva and should be approved by the end of 2023. Nevertheless, since the US Department of Transportation’s National Highway Traffic Safety Administration is a contracting…