Now that you know about the dangers of hydrogen as a fuel source, should you be
terrified by the prospect of having a tank full of it in your car? Not
necessarily. Because hydrogen gas is so light, it disperses rapidly, mixing with
the surrounding air and rapidly rising through it. Although pure hydrogen
ignites quite easily, in reality, this diluted hydrogen mixture is no more
likely to catch fire than gasoline is. And because it rises it isn't likely to
remain near the ground, where it's most likely to harm people.
The most famous hydrogen fire in history was probably the explosion of the
German airship Hindenburg in 1937. No one is exactly sure how the fire started
-- there are a few theories -- but the Hindenburg contained a large quantity of
hydrogen, which burst into flame along with the airship's skin. Of the 97
passengers and crewmembers on board the Hindenburg, 35 died. This harmed the
reputation of hydrogen for many decades and most likely slowed its use as a
fuel; however, there's no evidence that any of the victims were killed by the
hydrogen fire itself. Most died when they panicked and jumped out of the
airship. The rest were killed when the fire spread to the engines, as result of
the airship's burning skin. The hydrogen, meanwhile, rose above the passengers
and crewmembers, keeping the hydrogen fire above the mayhem happening below.
Because a hydrogen fire doesn't radiate as much heat as most fires do, it is
less likely to cause secondary fires. This doesn't mean that the hydrogen fire
wouldn't burn you if you touched it -- it's still plenty hot -- but it's less
likely to spread. As for the hydrogen being odorless and undetectable, this can
be offset to some extent by the addition of odorants to hydrogen fuel, giving
the hydrogen an artificial yet detectable smell. As the hydrogen disperses the
odorant won't necessarily travel with it, but you'll be able to determine that a
hydrogen leak has occurred and take appropriate action.
As for the danger of asphyxiation -- this is really only a problem in an
enclosed space, such as a garage. If a hydrogen leak occurs in the open, the
rapid dispersal of hydrogen means that it's unlikely that there will be a large
enough concentration of the gas to present a breathing hazard.
This doesn't mean that hydrogen shouldn't be treated with a healthy respect for
its dangers, but in practice, these dangers are unlikely to be any greater than
those of gasoline. In fact, with its rapid dispersal and tendency to rise,
hydrogen could pose less of a threat than the fuels we use now.
Montana, USA
Morocco, Rabat
Jamaica, Kingston
Arvada, Colorado
Savannah, Georgia
Hungary, Budapest
Fairfield, California
Columbia, Missouri
Venezuela, Caracas
Al Ain, United Arab Emirates, Al Ain, UAE