In the 1930’s, the New Zealand government declared to farmers that they had discovered the best ragwort killer. Ragwort, is a weed and the scourge of farmers.
The weed killer used high concentrations of sodium chlorate.
This meant, unfortunately, that when it was used (in liquid form) it often came into contact with clothing. Clothes that were made of organic materials.
The mixture was potentially lethal and if it came into close contact with a spark (or cigarette) it could possibly explode.
Nowadays, the ragwort flea beetle is used to fight the weed.
Article adapted from an article in New Scientist magazine, 11th December 2004 on pages 48 – 49, ‘Farmer Buckley’s Exploding Trousers’.