These documents cover both the risks posed by hydrogen in its different forms and how to ameliorate them.

Another acceptable method for radiation protection is material shielding by liquid hydrogen and water.

When powered by pure hydrogen, fuel cells have none of the environmental problems associated with gasoline.

Fuel cells (only if powered by hydrogen produced by one of the above approved generators, not from fossil fuels).

The engine uses regenerative cooling by liquid hydrogen.

The stars in the nebulae shine by burning hydrogen.

Z is the star's metallicity, the mass fraction not accounted for by hydrogen or helium.

The nitrile of 6 was reduced to the amine to give 7 by Palladium and hydrogen.

Reduction of this product by hydrogen over a palladium catalyst leads to terbutaline.

Beketov discovered displacement of metals from solutions of their salts by hydrogen under pressure.