there was a bunch of farmers in NZ around the 30s who survived
exploding pants...
they proved it...
in the 30s, there was a proliferation of ragweed which the farmers
tried to control with a certain herbicide...
well, that herbicide ignited when hit with stuff or in radiant
heat... and more, if you washed it with the soap they had at that
time, the pants became even more volatile...
they proved that the pants burned very very rapidly when exposed to
the herbicide 
