Safety of hydrogen fuel

The safety concern of using hydrogen fuel is over-exaggerated. Although hydrogen is a highly flammable, with careful handling, it can be safer than other conventional fuels.

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Many were shocked by the Hindenburg disaster in 1937. An airship loaded with hydrogen exploded and turned into a huge fireball. Although hydrogen contributed intensity of the flame, it is less explosive than conventional fuels. Hydrogen has a relatively low ignition energy of 0.02 mJ and it is 22 times less explosive than gasoline vapor. Similar to the measures implemented in petrol vehicles, potential hydrogen vehicle hazards can be avoided through leakage prevention and detection, as well as ignition prevention. Actually, hydrogen fuel has an excellent record in safety compared with other fuels.

During the generation of hydrogen through water electrolysis, an explosive product is formed only when more than 4% of hydrogen is present in oxygen or more than 5% of oxygen is present in hydrogen. Technologies such as PEM water electrolysis can eliminate the concern by producing nearly pure hydrogen. In fact, other fuels such as gasoline, and natural gases are also explosive, and they are widely adopted despite their safety concern. With better technologies being developed, the safety of hydrogen fuel will no longer be a concern.

The following video compares leakage and ignition between the hydrogen fuel cell and gasoline vehicles.