Considering both the physical abuse which vending machines often receive, and the normal skill sets of the workers maintaining them, I'd rather not be in any building containing one of these.<p><a href="https://en.wikipedia.org/wiki/Hydrogen_safety" rel="nofollow">https://en.wikipedia.org/wiki/Hydrogen_safety</a><p>> Hydrogen has one of the widest explosive/ignition mix range with air of all the gases with few exceptions such as acetylene, silane, and ethylene oxide, and in terms of minimum necessary ignition energy and mixture ratios has extremely low requirements for an explosion to occur. This means that whatever the mix proportion between air and hydrogen, when ignited in an enclosed space a hydrogen leak will most likely lead to an explosion, not a mere flame.[2]