During the Vietnam War, composition C-4 plastic explosive was used for virtually anything from cooking coffee to blowing up ammunition dumps and clearing landing zones. It came in white bars about one foot long, one inch thick and three inches across, wrapped in olive drab cellophane. It could be safely dropped, cut, pulled into long cords or stuffed into cracks. It was detonated by blasting caps, which had to be carried in special small wooden boxes and were much more dangerous. When ignited in the open, C-4 burned with an extremely hot white flame but did not explode. It's primary use in this configuration, strictly against policy, was for heating C-ration cans.