PICRIC ACID undergoes vigorous reactions with both oxidizing or reducing agents. Burns if ignited by a flame and continues to burns quietly if the quantity is small or, if large, is thinly spread over an area. The dry compound can explode if shocked or exposed to heat. Wetting significantly reduces the tendency to explode. Readily forms salts on contact with many metals (including copper, lead, mercury, zinc, nickel, iron) . The salts are sensitive explosives when subjected to heat, friction, or impact. Contact with concrete floors may form the friction-sensitive explosive calcium picrate [Urbanski, 1964, vol. 1, p. 518]. Contact with metallic zinc or lead can cause detonation. Salts with ammonia, amines and complexes with hydrocarbons are less sensitive [Kirk-Othmer, 1965, vol. 8, p. 617].
Some are toxic and may be fatal if inhaled, swallowed or absorbed through skin. Contact may cause burns to skin and eyes. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause pollution.
Crystallise the acid first from acetic acid, then acetone, toluene, CHCl3, aqueous 30% EtOH, 95% EtOH, MeOH or H2O. Dry it in a vacuum for 2hours. Alternatively, dry it over Mg(ClO4)2 or fuse (CARE) and allow it to solidify under a vacuum three times. Because it is EXPLOSIVE, picric acid should be stored moistened with H2O, and only small portions should be dried at any one time. The dry acid should NOT be heated. [Beilstein 6 IV 1388.]
Explosives, matches; in leather industry; electric batteries; etching copper; manufacture of colored glass; textile mordant; also as reagent.
Picric acid is a white to yellowish crystalline substance, soluble in most organic solvents and highly flammable. Picric acid is a derivative of phenol. It reacts with metals to form metal picrates, which like picric acid itself are highly sensitive. It is often used for tissue fixative (Bouin solution) for histology specimens, as a booster to detonate another, less sensitive explosive, such as trinitotoluene (TNT). It is used in the manufacture of fireworks, matches, electric batteries, coloured glass, dyes, antiseptics, explosives, disinfectants, leather industries, pharmaceutical, and textile. Picric acid is also used as a yellow dye, as an antiseptic, and in the synthesis of chloropicrin, or nitro-trichloromethane. Picric acids are highly sensitive to heat, shock, or friction and because of the explosive nature it is among the most hazardous substances found in the laboratory.
A paste or slurry consisting of the yellow crystalline solid mixed with water. The dry compound is a sensitive high explosive. The mixture with water is considered safe for storage, handling and shipping. Can be detonated with a number 8 electric blasting cap. The primary hazard is blast where the entire load explodes instantaneously and not from flying projectiles fragments. Can explode under prolonged exposure to heat.
Air & Water Reactions
Preparation of organic derivatives for identification.
Contact dermatitis occurred primarily in the explosives
Also known as picronitric acid, trinitrophenol, nitroxanthic acid, carbazotic acid or phenoltrinitrate, C6H2(N02)3OH is yellow crystals that are soluble in water, alcohol, chloroform, benzene, and ether with a very bitter taste. It is derived by the nitration of phenolsulfonic acid, obtained by heating phenol with concentrated sulfuric acid, and is used for explosives, matches, electric batteries, and etching copper.