 Work conducted with perchloric acid must be conducted in fume hoods with a wash-down capability to prevent accumulation of oxidisers in the ductwork.On February 20, 1947, in Los Angeles, California, 17 people were killed and 150 injured when a bath, consisting of over 1000 litres of 75% perchloric acid and 25% acetic anhydride by volume, exploded.The O'Connor Electro-Plating plant, 25 other buildings, and 40 automobiles were obliterated, and 250 nearby homes were damaged.