When is it damaging?
Hydrogen is highly soluble in many rare earth and transition metals and is soluble in both nanocrystalline and amorphous metals. Hydrogen solubility in metals is influenced by local distortions or impurities in the crystal lattice. These properties may be useful when hydrogen is purified by passage through hot palladium disks, but the gas's high solubility is a metallurgical problem, contributing to the embrittlement of many metals, complicating the design of pipelines and storage tanks.
According to a study done by Helmut Fend (who had always been a fierce proponent of comprehensive schools) revealed that comprehensive schools do not help working class students. He compared alumni of the tripartite system to alumni of comprehensive schools. While working class alumni of comprehensive schools were awarded better school diplomas at age 35, they held similar occupational positions as working class alumni of the tripartite system and were as unlikely to graduate from college.