Picric acid hazard

Derivation By partial reduction of picric acid. Hazard May explode when shocked or heated, dangerous fire risk. 

Mark Cameron, Picric Acid Hazards, June 18,2002, http //oag.ca.gov/ sites/all/files/agweb/pdfs/cci/safety/picric.pdf, (accessed Mar 2015). 

VIII. Explosive Characteristics. Picric Acid is generally considered to be a relatively insensi tive but brisant expl. On a qualitative sensitivity scale of comparing common expls, PA would be judged to be more sensitive than TNT but appreciably less sensitive than Tetryl. Its power and brisance are also similar to those of TNT (112% TNT in the Ballistic Mortar 101% of TNT in the Trauzl Block and 107% in the plate dent test (Ref 48). In this section we will consider the steady detonation parameters. initiation characteristics and potential hazards of PA... 

Picric acid, in common with several other polynitrophenols, is an explosive material in its own right and is usually stored as a water-wet paste. Several dust explosions of dry material have been reported [1]. It forms salts with many metals, some of which (lead, mercury, copper or zinc) are rather sensitive to heat, friction or impact. The salts with ammonia and amines, and the molecular complexes with aromatic hydrocarbons, etc. are, in general, not so sensitive [2], Contact of picric acid with concrete floors may form the friction-sensitive calcium salt [3], Contact of molten picric acid with metallic zinc or lead forms the metal picrates which can detonate the acid. Picrates of lead, iron, zinc, nickel, copper, etc. should be considered dangerously sensitive. Dry picric acid has little effect on these metals at ambient temperature. Picric acid of sufficient purity is of the same order of stability as TNT, and is not considered unduly hazardous in regard to sensitivity [4], Details of handling and disposal procedures have been collected and summarised [5],... 

The powdered oxidant functions as an explosive when mixed with finely divided metals, organic materials or sulfur, which increase the shock-sensitivity up to that of picric acid [1]. The hazardous properties of such mixtures increase as the particle size of the oxidant salt decreases [2],... 

PA PCP PCR PFA PGB PHA PID PLC PMACWA PMD POTW ppm PRH PRR psi psig PTFE PVDF PWS picric acid pentachlorophenol propellant collection reactor perfluoroalkoxy product gas burner preliminary hazards analysis proportional integral differential controller programmable logic control Program Manager for Assembled Chemical Weapons Assessment projectile mortar demilitarization (machine) publicly owned treatment works parts per million projectile rotary hydrolyzer propellant removal room pounds per square inch pounds per square inch gauge polytetrafluoroethylene (Teflon) polyvinylidene fluoride projectile washout system... 

Reactivity. Chemicals that react violently with air or water are considered hazardous examples are sodium metal, potassium metal, and phosphorus. Reactive materials also include strong oxidizers such as perchloric acid, and chemicals capable of detonation when subjected to an initiating source, such as solid, dry < 10% H2O picric acid, benzoyl peroxide, or sodium borohydride. Solutions of certain cyanide or sulfides that could generate toxic gases are also classified as reactive. The potential for finding such chemicals in a refinery is... 

All whistle compositions are hazardous to handle, but those containing picrates and gallates are also shock-sensitive with a tendency to explode. Picric acid (2,4,6-trinitrophenol) is, in fact, classed as a high explosive. 

Picric acid was used in grenade and mine fillings and had a tendency to form impact-sensitive metal salts (picrates) with the metal walls of the shells. The filling of mines and grenades was also a hazardous process, since relatively high temperatures were needed to melt the picric acid. Some of the properties of picric acid are presented in Table 2.9. 

Care and caution are essential in the use and storage of picric acid at workplaces because shock-sensitive metal picrates are hazardous. 

Cleaning Up The filtrate from this reaction and the product as well can be disposed of by dilution with a large volume of water and flushing down the drain. Larger quantities of moist picric acid (1 g) can be reduced with tin and hydrochloric acid to the corresponding triaminophenol. Dry picric acid is said to be hazardous and should not be handled. 

Phosphoric Acid Phosphorus Photoallergens Photochemical Oxidants Phthalate Ester Plasticizers Physical Hazards Picloram Picric Acid Piperazine Piperonyl Butoxide "Plants, Poisonous" Platinum (Pt) Plutonium (Pu) Poinsettia Poisoning Emergencies in Humans Pokeweed Pollutant Release and Transfer Registries (PRTRs) Pollution Prevention Act "Pollution, Air" "Pollution, Air Indoor" "Pollution, Soil" "Pollution, Water" Polybrominated Biphenyls (PBBs) Polybrominated Diphenyl Ethers (PBDEs) Polychlorinated Biphenyls (PCBs)... 

Derivation Prepared from m-cresol by a process similar to that in picric acid is prepared from phenol. Hazard Explodes at 300F (148.8C), severe explosion risk when shocked or heated. 

EXPLOSION and FIRE CONCERNS flammable solid NFPA rating Health 3, Flammability 4, Reactivity 4 very unstable severe explosion hazard when shocked or exposed to heat can form salts of picric acid that are initiators and shock-sensitive forms unstable salts with concrete, ammonia, bases, and metals (e.g., lead, mercury, copper, and zinc) can form extremely explosive mixtures with uranium perchlorate mixtures with aluminum and water ignite after a delay period incompatible with all oxidizable substances, albumin, gelatin, and alkaloids toxic gases and vapors, such as carbon monoxide and oxides of nitrogen, may be released in a fire use flooding quantities of water for firefighting purposes. 

Solids, such as picric acid, are considered wetted explosives. If allowed to dry out, they are classified as Class 1 Explosives. However, they present only a limited hazard as long as the water is present and, therefore, they are considered flammable solid materials. 

Picric acid, C H2(N02)30H, for example, becomes a high explosive when dried out and is sensitive to shock and heat. The hazard class for picric acid is 4.1 Hammable Solid. It is considered a wetted explosive. The name would indicate acid, however, the corrosivity of picric acid is far outweighed by its explosive dangers. The slightest movement of dry picric acid may cause an explosion. Picric acid, when shipped, is mixed with 12 to 20% water to keep it stable. When this water evaporates in storage over time, the material becomes explosive. 

Phenol was needed to produce picric acid, an explosive relied upon primarily by our Prench allies. Sulfuric acid was needed to produce powder. Both hazardous materials were produced in large quantities. 

Finding DII AEA-4. The generation of new energetic compounds trinitrobenzoic acid, picric acid, and trinitrobenzene (TNBA, PA, and TNB) in the course of processing increases the complexity and hazards of the SILVER IF process. Although the explosion hazard is reduced as the energetic feed is consumed, it is not completely eliminated until all energetic intermediates are destroyed. 

Generally, the drier or more desiccated a compound with potential explosive properties becomes, the greater the risk for an explosion. Picric acid, aka trinitrophenol, is related very closely to TNT (trinitrotoluene) and it is used in some laboratory operations. Normally, picric acid comes in a moist state from the supplier, and in this state it is safe to handle and store. However, when picric acid reaches a dry state it has the same potential as TNT to be explosive. Metal salts of picric acid are also known to be shock-sensitive. Picric acid needs to be on a timed disposal protocol to ensure that it is discarded before it can dry out and become hazardous. 

While many compounds degrade to harmless by-products, some chemicals degrade into more hazardous substances over time and need to be tracked. For chemicals that degrade over time, it is necessary to date the label when it was received and when it was first opened. We have previously discussed how some compounds degrade to form dangerous products such as peroxides (see Section 5.3.2). These compounds must be carefully tracked and discarded after a specified period (see Table S.3.2.2 Peroxidizable Chemicals). Other compounds also need to be tracked by time in storage (see Special Topic 8.3.3.1 Picric Acid—A Potential Chemical Storage Hazard). 

PICRIC ACID—A POTENTIAL CHEMICAL STORAGE HAZARD... 

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