TNT was first synthesized in 1863 by German chemist Julius Wilbrand and was originally used as a yellow dye. Its potential as an explosive was not recognized for three decades, mainly because it was so much less sensitive than other explosives known at the time. Its explosive properties were discovered in 1891 by another German chemist, Carl Häussermann. TNT can be safely poured when liquid into shell cases, and is so insensitive that in 1910 it was exempted from the UK’s Explosives Act 1875 and was not considered an explosive for the purposes of manufacture and storage.

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TNT is poisonous, and skin contact can cause skin irritation, causing the skin to turn a bright yellow-orange color. During the First World War, female munition workers who handled the chemical found that their skin turned bright yellow, which resulted in their acquiring the nickname “canary girls” or simply “canaries”.