Hydrogen is a real b!+c# kitty of an element to handle. Not only is it very likely to leak out of virtually any coupling through which it passes, it is highly reactive and forms hydride compounds with just about most metallic elements, and the least spark around a leak in an atmosphere that contains 20% oxygen is very likely to result on one tremendous flash explosion.
But it does get bottled up and sold as an industrial chemical.
Smoking Lamp Is Out.