I don't know if liquid air has the same
composition as gaseous air, but if it does, even that danger
won't exist.
Even if the composition is somewhat different it would not be toxic. During the short time it takes to escape from an accident people can breathe all kinds of things, such as pure oxygen, without ill-effects.
Actually LH has a very good safety record.
LNG ships have been hauling vast quantities of liquefied gas for decades without a first-world accident as far as I know. There was an explosion in Algeria. See:
http://www.ch-iv.com/lng/lngfact.htm
http://www.boston.com/news/nation/washington/articles/2005/01/22/potential_of_catastrophic_fire_from_terrorist_attack_worries_lng_opponents/
- Jed
