Ammonia and hydrogen represent opposite ends of the spectrum with regard to the potential blast loading resulting from an accidental vapor cloud explosion (VCE), although many in industry have expressed doubts as to whether either of these fuels actually pose a VCE hazard. Ammonia is some-times discounted as a VCE hazard due to the perceived difficulty in igniting an ammonia-air mixture and/or because of its low laminar burning velocity. Hydrogen is sometimes discounted as a VCE hazard due to the ease with which a hydrogen-air mixture can be ignited and/or because of its buoy-ancy.

The purpose of this guide is to assist users of codes and standards that apply to hydrogen application and use in understanding and applying the approval, certification, listing, and labeling provisions of the codes and standards, in any application where the required certification, listing, and labeling of services, methods, or equipment has not yet been established or achieved.  

VIII.6  Hydrogen Safety Panel, Safety Knowledge Tools and First Responder Training Resources

This document and its companion document, Safety Standard for Oxygen and Oxygen Systems (NSS1740.151996),are identified as Tier 2 Standards and Technical Requirements in the NASA Safety and Documentation Tree (NHB 1700.1 1993). The information presented is intended as a reference to hydrogen design and practice and not as an authorizing document. The words "shall" and "must" are used in this document to indicate a mandatory requirement, and the authority for the requirement is given.