Permitted/permissible explosives

Fig. 153. Determination of incendiveness of a permitted (permissible in the U.S.A.) explosive in a firedamp atmosphere, by the up-and-down method, according to Grant...

Apart from the reaction of the decomposition of nitrate esters some other changes can occur in mixed explosives, such as the reaction of the oxidation of aluminium, particularly marked in watcr-gel explosives. Also permitted (permissible) explosives containing ion exchange mixtures of sodium nitrate witli ammonium chloride a double exchange reaction can occur ... 

Non-Permissible (Amer) or Non-Permitted Brit) Explosives. See under Commercial or Industrial Explosives in Vol 3, C435-R to C437-R, and Coal Mining Explosives, Testing for Permissibility in Vol 3, C368-R ff... 

P (Explosives). Brit permitted expls categorized as PI, P2, P3, P4 and P5. See under Permissible and Permitted Explosives in this Vol Ref S. Fordham, High Explosives and Propellants , Pergamon Press, NY (1966), 90—96... 

Permissible or Permitted Explosives. In many coal mines there is a continual evolution of methane (firedamp) into the air of the workings. 

It will, therefore, be seen that the best and safest practice is to use in each situation in the coal mine an explosive which is best adapted for the operation in hand. The use of unnecessarily weak explosives, even though apparently safer in some tests, is often a disadvantage and can be dangerous. These considerations have led to the development of a series of types of explosives suited for particular purposes in coal mines and subjected to tests relevant to their individual uses. Thus, in Britain there are now five classes of permitted explosives. In Germany there are three classes. In the U.S.A. geological conditions are different and the hazards are less than in Europe, and it has been possible to work throughout with the strongest types of permissible explosives. 

Permissible Explosive. The American equivalent to British Permitted Explosive. 

Corresponding explosives are known in Belgium as explosifs SCP (securite-grisou-poussiere), and in the USA as permissible explosives. In Great Britain they are called permitted explosives, and are to be distinguished from authorized explosives which... 

Civil explosives are further sub-divided into permitted or permissible explosives and non-permitted explosives. Two types of civil explosives namely ammonium nitrate-fuel oil (ANFO) and emulsion explosives dominate the rock blasting scene in the USA. 

A permitted or permissible explosive is one that has been allowed for use in gas- or dust-filled coal mines. These explosives produce strong detonation but... 

Class VII. Permissible Dynamites, known in Great Britain as Permitted Dynamites are expls so formulated as to be suitable for use under conditions where explosive gas mixtures or dust-air mixtures may be present, as in coal mines (Ref 62, p641)... 

American Permissible Explosives. See under Permissible and Permitted Explosives American Powder, also called White German Powder. See Augendre Powder... 

Ammi sfble(Ital). Permissible or "Permitted (Explosive)... 

Further development of expls safe against firedamp and/or coal dust will be discussed in section II of this item, entitled Coal Mining Explosives, Permissible. In section I, which follows, are described commercial expls which are not permitted in gaseous and/or dusty coal mines, but can be used for many other purposes... 

Coal Mining Explosives, Permissible (Permitted in GtBritain). This term applies to explosives which, because they have passed special prescribed tests, can be used in coal mines eontg firedamp and/or coal dust. These tests are described under COAL MINING EXPLOSIVES, TESTING FOR PERMISSIBILITY- Approved expls will not ignite expl mixts of firedamp, coal dust 8t air, when used under prescribed conditions. 

Ibid 425 (1910) (Explosibility of coal dust) 6)J.J.Rutledge C.Hall, USBurMines Bull 10 (1912) (Use of permissible expls) 7)C. Hall et al, Ibid 15 (1912) (Investigation of expls used in coal mines) 8)Marshall 1 (1917), 44-47 2 (1917), 582-606 (Permitted expls) 8a)Colver (1918), 247 681 (Nauck-hoff s expls) 9)Barnett (1919), 117-42 (Safety coal mine expls) 10)E.Lemaire, AnnMines-Belg 23, 649(1922) (Sheathed expls) 10a)C. A.Taylor W.H.Rinkenbach, USBurMines Bull 219 (1923), 107-14 (The thermochemistry of expln) ll)H.Henkei, SS 22, 173 (1927)... 

PEP-2 PEP-3 PIPE = mixtures of PETN and Gulf Crown Oil (USA) perchlorate d ammonium 17 perchlorate de barium 29 perchlorate explosives 247 perchlorate de guanidine 157 perchlorate d hydrazine 182 perchlorate de lithium 205 perchlorate de potassium 263 perchlorate de sodium 292 percussion cap percussion primer 95 201 202 247 267 288 289 perforation of oil and gas wells 247 perle d allumage = squib 43, 236 Perlit = picric acid (german) 256 permissibles permitted explosives 14 75 86 88 248 370 peroxides 31 170 252 346 371 peroxide de benzoyle 31 peroxide de tricycloacetone 346 peroxide de zinc = zinc peroxide 371 Perspex = acrylic acid methylester polymer (same as Plexiglas ... 

Such explosives are known as permissibles in the USA, as permitted explosives in the United Kingdom, as Wettersprengstoffe in Germany, as explosifs antigrisouteux in France, and as explosifs S.G.R (securite grisou poussieres) in Belgium. 

Uses As blasting explosives for mining. For blasting in gaseous and dusty coal mines only approved Safety Explosives may be used they are called Permitted Explosives (England) or Permissible Explosives (U. S.). Term Safety Explosives now obsolete. 

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