
610 Fuel Cells
limits based on the volume percent of hydrogen in oxygen at 14.7psia (1atm,
101kPa) are 4.0 and 94.0. Hydrogen leaks can support combustion at very
low ow rates, as low as 4 μg/s.
Besides the ammability concern, hydrogen simply vented to the atmo-
sphere also poses a potential problem. Hydrogen collects under roofs and
overhangs, where it forms an explosion hazard; any building that contains
a potential source of hydrogen should have good ventilation, should have
strong ignition suppression systems for all electric devices, and should pref-
erably be designed to have a roof that can be safely blown away from the
rest of the ...