Explosive substance seized at Mallorca school

Specialists from the Guardia Civil Explosives Disposal and CBRN Defence Group removed the three containers containing a total of 75 grams of picric acid. The Guardia Civil removed several bottles of this substance from the laboratories of three schools and from the storage room of a private home in Palm at the end of last year and have been informing schools that picric acid was part of chemical compound kits some 30 years ago and that it is a toxic substance.

For this reason, schools were asked to review the inventory of laboratories and, if this substance was located, to report it and avoid handling it. Picric acid is an organic compound with the formula (O2N)3C6H2OH. Its IUPAC name is 2,4,6-trinitrophenol (TNP). The name “picric” comes from Greek meaning “bitter”, due to its bitter taste. It is one of the most acidic phenols. Like other strongly nitrated organic compounds, picric acid is an explosive, which is its primary use. It has also been used as medicine (antiseptic, burn treatments) and as a dye.

By far the greatest use of picric acid has been in ammunitions and explosives. Explosive D, also known as Dunnite, is the ammonium salt of picric acid. Dunnite is more powerful but less stable than the more common explosive TNT (which is produced in a similar process to picric acid but with toluene as the feedstock).

Picramide, formed by aminating picric acid (typically beginning with Dunnite), can be further aminated to produce the very stable explosive TATB. It has found some use in organic chemistry for the preparation of crystalline salts of organic bases (picrates) for the purpose of identification and characterisation.