Proper handling of picric acid:
(1) The chemical should be stored with > 30% water ("wet"). "Dry" picric acid (crystals or aqueous mixtures < 30% water) is more explosive than TNT (Class A); "wet" picric acid is flammable.
(2) Contact with metals (copper, nickel, lead, iron, zinc), metallic salts, amines, bases, plaster or concrete results in picrate salts which are highly explosive.
(3) The dry form and picrate salts are highly sensitive to heat, friction and shock.
(4) Storage in containers with metal lids or ground glass stoppers can result in explosions when the lids/stoppers are turned. The closure surfaces of a container should be wiped with a damp cloth after each use.
(5) Picric acid is a strong irritant and is a poison if absorbed or ingested.
(6) Metal spatulas should not be used to remove the chemical.
(7) Old containers of picric acid that have dried out should not be moved at all. They should be handled only by a trained disposal team taking explosion and chemical precautions.
(8) Containers should be stored in a cool, dry place away from heat, open flame and vibration in a closed chemical safety cabinet.
(9) All stores of picric acid should be entered into an inventory control system for regular inspection. The minimum possible quantity required should be stored. Stores of picric acid should be kept well-hydrated with distilled water, with the date of last rehydration recorded. Supplies more than 2 years old should be considered for disposal.
