Is there any guidance available to help hazard analysis teams evaluate the likelihood of ignition for hydrogen releases?

There is no consensus on the “correct” answer. Small leaks of short duration have a much lower
probability of ignition compared to large releases. Ignition probability is affected by the operating
conditions, whether the release is from a leak or vent stack, and the surrounding environment. Since the
probability of ignition is high, hazard analyses will usually assume the hydrogen will likely ignite and
should consider the potential consequences of ignition to the system and surroundings.