What are good resources describing the properties of hydrogen?

The National Fire Protection Association (NFPA), the Compressed Gas Association (CGA), and the Society of Fire Protection Engineers (SFPE)   represent the U.S. fire protection and engineering community, and these organizations publish handbooks and standards/guidelines that describe the properties of hydrogen. There are many other organizations and documents that provide similar information. The Center for Hydrogen Safety within AIChE has training material for the properties and safe handling of hydrogen at the following link:

Fundamental Hydrogen Safety Credential