Is hydrogen considered poisonous?

Hydrogen is not classified as a poisonous gas. It is a relatively inert element that does not have toxic effects on the human body in the same way that many other gases do. The key point is that hydrogen requires oxygen to support combustion and is necessary for many metabolic processes involving oxygen. Thus, while hydrogen is not directly poisonous, it does not support life on its own. In an atmosphere lacking oxygen, hydrogen cannot sustain life.

This understanding is crucial in contexts where hydrogen might displace oxygen in an enclosed space, leading to a risk of asphyxiation rather than poisoning. Moreover, while hydrogen can be combustible and hazardous in high concentrations due to the potential for explosions, this does not categorize it as a poison in the traditional sense. The ability of hydrogen to support life is inherently linked to the presence of oxygen, which is vital for human survival.