COMMON NAME – Picric Acid

NAME – Trinitrophenol

CHEMICAL NAME – 2,4,6-Trinitrophenol

FOREIGN NAMES – Lyddite (Britain), Mélinite (France), Bittersäure, Füllpulver 1888 [Fp 88] Pikrinsäure, Granatefullung 88 [Grf 88] (Germany), Melinita, Pertite, Trinitrofenolo (Italy),

Oshokuyaku (Japanese Army), Pikurinsan, Shimose, Shimosite, & Shimose Bakuyaku (Japanese Navy), Melinit, Pikribovaya kislota (Soviet Union), Picrinita (Spain), Pikrinsyra, Cronite (Sweden),

Pikrinsäure (Switzerland)

TYPE – High explosive

DATE OF DISCOVERY – 1771 (as a dye)

DATE FIRST USED AS AN EXPLOSIVE – 1885

COUNTRY OF ORIGIN – Great Britain

MOLECULAR FORMULA – C₆H­₃N₃O₇

MOLECULAR WEIGHT – 229

DENSITY – 1.71 g per ml when cast

NORMAL STATE – Crystalline solid

PHYSICAL APPEARANCE/COLOR – Pale to bright yellow

INITIATION – No. 6 Blasting Cap. Minimum 0.24 g Lead azide, 0.26 g Mercury fulminate

SENSITIVITY – Slightly more sensitive to impact than TNT

STABILITY – Comparable to TNT when properly stored, wet with 10% water in a cool, dry place

DETONATION VELOCITY – 7,350 m/s (24,114 fps)

RE FACTOR (BRISANCE) [TNT=1.0] – 1.17

TOXICITY – Highly irritating to nose, throat, lungs and eye, toxic absorption through skin

MELTING POINT – 123^o C. (253^o F.)

IGNITION POINT – Detonates when heated to 300^o  C. (572^o F.)

SOLUBILITY – Slightly soluble in water

APPLICATIONS – PRINCIPLE USES – Bursting and demolition charge, Component of composite bursting charges, production of Explosive D

     Picric acid was in wide use long before it was adopted as one of the first military high explosives. The acid is an intense yellow dye when it comes into contact with many fabrics, as well as human skin, and became one of the first commercial artificial dyes in wide use. It is a powerful explosive and especially sensitive when in the dry condition. The power of Picric acid puts it in the same class of explosive as TNT. It is also highly shock resistant, which helped it become the high explosive filler of choice for artillery shells in the latter part of the 1800s and into the 20^th Century. Picric acid can be melted and poured into shells, bombs, and other ordnance, increasing its value as a general explosive. One of the very strong drawbacks to Picric acid is that it creates very sensitive and unstable picrate salts when it comes into contact with many metals. Shells to be filled with Picric acid had to have all the surfaces that may come into contact with the explosive covered with an asphalt paint to prevent the base metal from corroding. The explosive had such an importance to the German military during World War I that they worked diligently to prevent the raw material for the acids manufacture, Phenol, out of the hands of the Allies. This shortage of raw materials helped drive the search for new explosives, aiding in the adoption of TNT in the United States. Picric acid is the base material for the manufacture of Ammonium picrate, known in the United States under its original code name “Explosive D.”