Hazards from explosion

Hazards from explosions, spills, and extreme working conditions should be considered according to national regulations. 

Huang, L.C.P., Prediction of Debris Hazards from Explosions in Buildings, Twenty-First Explosives Safety Seminar, Houston, TX, Aug 1984. 

Hackett, 0. F. and Peterson, R. 0., Missile Hazards from Explosions in Ships, Nineteenth Explosives Safety Seminar,... 

Rakaczky, J.A., The Suppression of Thermal Hazards from Explosions of Munitions A Literature Survey, BRL Interim Memorandum Report No. 377> Aberdeen Proving Ground, Md.,... 

Permissible That which is allowable or permitted. It is most widely applied to mine equipment and explosives of all kinds that are similar in all respects to samples that have passed certain tests of the MSHA and can be used with safety in accordance with specified conditions where hazards from explosive gas or coal dust exist. 

The presence of antioxidants in eluents and extraction solvents Antioxidants can be readily oxidized electrochemically and generate high background currents or interfering broad peaks. Thus, eluents and extraction solvents containing such compounds should be either avoided or purified before use. For example, ethers, such as diethyl ether, diisopropyl ether, and tetrahydrofuran are likely to contain up to 0.1% (w/v) pyrogallol or quinol (hydroquinone) as stabilizer. If the stabilizer is removed, peroxides will form and their concentration will increase with time unless the solvent is stored under nitrogen. Not only do peroxides present a hazard from explosion, but they may also oxidize susceptible analytes. Methyl f-butyl ether (MTBE), on the other hand, is stable to oxidation. 

Fire and Explosion Index (Ffrom fires and explosions. frequency The rate at which observed or predicted events occur. HAZOP HAZOP stands for hazard and operabihty studies. This is a set of formal hazard identification and ehmination procedures designed to identify hazards to people, process plants, and the environment. See subsequent sections for a more complete description. 

Refrigeration Loss of containment of a liquefied gas under pressure and at atmospheric temperature causes immediate flashing of a large proportion of the gas. This is followed by slower evaporation of the residue. The hazard from a gas under pressure is normally much less in terms of the amount of material stored, but the physical energy released if a confined explosion occurs at high pressure is large. 

Hydroprocesses Hydrogen is chemically stable and relatively unreactive at ordinary temperatures most processes utilizing it require a catalyst. Above 500°C it reacts readily with oxygen and confined flammable mixtures explode violently if ignited Main hazards fire, explosion, metallurgical problems arising from hydrogen attack... 

Can hazards from the reaction be reduced by changing the relative concentration of reactants or other operating conditions Can side reactions produce toxic or explosive material, or cause dangerous fouling ... 

Employers, at a minimum, must have an emergency action plan that will facilitate the prompt evacuation of employees when there is an unwanted release of a highly hazardous chemical. This means that the employer s plan will be activated by an alarm system to alert employees when to evacuate, and that employees who are physically impaired will have the necessary support and assistance to get them to a safe zone. The intent of these requirements is to alert and move employees quickly to a safe zone. The use of process control centers or buildings as safe areas is discouraged. Recent catastrophes indicate that lives are lost in these structures because of their location and because they are not necessarily designed to withstand over-pressures from shock waves resulting from explosions in the process area. 

You should be able to estimate the quantities of material contained within a section from mechanical and operating data. You should also consider operating conditions, which should be available from the plant mass balance or from actual operating data. Simple hazard models can predict the size of vapor clouds, radiation hazards from fires, and explosion over-pressures. Such models are available from a number of sources. 

The total consumption type of burner consists of three concentric tubes as shown in Fig. 21.5. The sample solution is carried by a fine capillary tube A directly into the flame. The fuel gas and the oxidant gas are carried along separate tubes so that they only mix at the tip of the burner. Since all the liquid sample which is aspirated by the capillary tube reaches the flame, it would appear that this type of burner should be more efficient that the pre-mix type of burner. However, the total consumption burner gives a flame of relatively short path length, and hence such burners are predominantly used for flame emission studies. This type of burner has the advantages that (1) it is simple to manufacture, (2) it allows a totally representative sample to reach the flame, and (3) it is free from explosion hazards arising from unbumt gas mixtures. Its disadvantages are that (1) the aspiration rate varies with different solvents, and (2) there is a tendency for incrustations to form at the tip of the burner which can lead to variations in the signal recorded. 

Powder Explosions. See under Coal Dust Explosion Hazards from its Uses in Vol 3, C359-R Dust Explosions in Vol 5, D1578-R and Powder-Air Explosions and Detonations in this Vol... 

Main hazards fire, explosion, metallurgical problems arising from hydrogen attack... 

Explosihility screening. In the literature an extensive collection of explosion properties of chemical compounds can be found. However, if literature is unavailable or properties have not been examined yet, a number of initial screening techniques exist. If the checks for explosibility of the starting materials, intermediates, or products reveal a great hazard from deflagration or detonation, it is advisable to abandon the process. 

The only disadvantage to the use of hydrogen as a carrier gas Is the real or perceived explosion hazard from leaks within the column oven. Experience has shoim that the conditions required for a catastrophic explosion may never be achieved in practice.. However, commercially available gas sensors will automatically switch off the column oven and carrier gas flow at air-hydrogen mixtures well below the explosion threshold limit [143]. 

Chapters 3, 4, and 5 describe various methods of evaluating hazard consequences and risk associated with buildings in process plants. Buildings for which there remains a concern following evaluation may be at significant risk from explosion or fire hazards. As discussed in Chapter 5, these buildings may be candidates for risk reduction. 

Originally, equipment was made largely from wood or gun-metal and often rubber lined. These materials give the lowest hazards from friction with explosives. Nowadays, improved standards of engineering and of design have made it possible to employ stainless steel and plastics in the construction of explosive machinery with considerable increase in mechanical efficiency. In this way not only can processes be carried out more rapidly, but the quantity of explosive present at any time is reduced, with consequent increase in overall safety. 

The method of mining is somewhat like driving two sets of tunnels at right angles through the strata. Most mines of this type do not present any hazard from methane and therefore non-permitted explosives can be used. The selection of powder or gelatine type of explosive depends on the nature of the rock and particularly on the wetness of the mine. 

The flammability and explosive hazard of ferrosilicon powder is increased substantially during grinding in a vibratory mill [1], Explosion hazards from air-hydrogen,—acetylene, or—propane mixtures formed during preparation of ferrosilicon containing alkaline earth additives are attributed to contact of barium or magnesium carbide or silicide additive with atmospheric moisture [2],... 

Although I had been aware during most of my career as a preparative chemist of a general lack of information relevant to the reactive hazards associated with the use of chemicals, the realisation that this book needed to be compiled came soon after my reading Chemistry Industry for June 6th, 1964. This issue contained an account of an unexpected laboratory explosion involving chromium trioxide and acetic anhydride, a combination which I knew to be extremely hazardous from close personal experience 16 years previously. 

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