Actually the Hindenberg was full of hydrogen, which is very combustible. “Hydrogen gas was used in lighter-than-air balloons for transport but is far too dangerous because of the fire risk (Hindenburg).”
http://www.webelements.com/
Nitrogen is only explosive when it’s heated, it combines directly with magnesium, lithium, or calcium. When mixed with oxygen and subjected to electric sparks.
And I hope not to have magnesium, lithium, or calcium anywhere near my cylinder.