Main Page | See live article | Alphabetical index Picric acid is the common term for the chemical compound 2,4,6-trinitrophenol; the material is a yellow crystalline solid. Like other highly nitrated compounds (eg. Trinitrotoluene TNT), picric acid is an explosive. When picric acid is dry, it is extremely sensitive to shock and friction, so laboratories that use it store it in bottles under a layer of water, rendering it safe. Glass bottles are required, as picric acid can form metal picrate salts that are even more sensitive and hazardous than the acid. Chemical Structure of Picric Acid Uses By far the largest use has been in munitions and explosives; it was known in World War I as Lyddite or Melinite The principal laboratory use is in microscopy, where it is used as a reagent for staining samples, e.g. Gram staining. Picric acid was one of the agents in the Halifax explosion. This article is from Wikipedia. All text is available under the terms of the GNU Free Documentation License.