Chemical explosions classification

Classification of explosives has been undertaken by many scientists throughout this century, and explosives have been classified with respect to their chemical nature and to their performance and uses. Chemical explosives can be divided into two groups depending on their chemical nature those that are classed as substances which are explosive, and those that are explosive mixtures such as blackpowder. 

The first edition of Dow s Fire and Explosion Index (F EI) Guide, published in 1964, was based on the Factory Mutual Chemical Occupation Classification Guide. As experience has been accumulated and evaluated, the Dow guide has gone through several revised and expanded editions. The current sixth edition was published in May 1987. It draws on NFPA 325M and 49. 

Another common classification of chemical explosives is primary or secondary. Primary explosives are highly unstable and are sensitive to heat or shock. Secondary explosives are also unstable compounds, but their sensitivity to heat or shock is lower than that of primary explosives. A booster is used to bring about detonation. Many polynitro explosives fall under the latter class. Whether... 

At Pantex, the preliminary hazards analysis takes the form of a questionnaire (PX-1245), which is used to collect information about facility inventories of highly hazardous chemicals, explosives, and nuclear material. This information serves as an objective basis for facility hazard classification. The information also allows ranking of facilities based on the quantity and form of nuclear material the eonsequences associated with an explosive event, as well as the type of explosives operation and the eonsequences of a release of highly hazardous materials. 

These facilities do not fall under the requirements of OSHA s Process Safety Management of Highly Hazardous Chemicals Explosives and Blasting Agents standard (PSM), 29 CFR 1910.119 (i.e., they are not gas plants, nor are they classified under Standard Industrial Classification code — SIC 1321) ... 

Pyrotechnic compositions can also be classed as chemical explosives Figure 2.1 Classification of explosive substances. 

Dow (Dow Chemical Company). 1987. Lire Explosion Index—Hazard Classification Guide, 6th ed.. American Institute of Chemical Engineers, New York. 

Davison, G., and Hewitt, C.N. (ed.) (1997) Air Pollution in the United Kingdom, Royal Society of Chemistry, London. Dow Chemical Company (1993) Dow s Fire and Explosion Index Hazard Classification Guide American Institute of Chemical Engineers. 

Dow Chemical Company (1994b). Dow s Fire and Explosion Index Hazard Classification Guide. 7th Edition. New York American Institute of Chemical Engineers. 

Explosive chemicals tend to be governed by separate legislation, e.g., in the UK, The Classification and Labelling of Explosives Regulations 1983. These require the HSE to classify any explosive before it may be supplied. Under the scheme, explosives are labelled according to a classification based on hazard division (Table 12.7), and on compatibility (Table 12.8), which takes into account their sensitivity, explosivity and chemical nature. Labels are diamond shaped the top half is reserved for the pictograph and division number, the bottom half shows the hazard code and the classification number. Figure 12.1 shows the label for Class 1, Division 1.1, 1.2 or 1.3 explosive. 

Explosives, See also Explosive chemicals Transportation carriage, 447, 460, 594 compatibility groups, 456 hazard classification, 447, 455 Exposure limits. See Hygiene standards Eye protection, 435... 

The approach to developing metrics for process safety is analogous to those that might be used to assess Occupational Exposure risk. One can cite as well several indices that have been developed as metrics for estimating and ranking the safety of a given process or chemical reaction, such as the DOW fire and explosion index,the Stoessel index ° for hazard assessment and classification of chemical reactions, the Inherent Safety Index, the Prototype Index for Inherent Safety, amongst others. ... 

More detailed check lists are given by Carson and Mumford (1988) and Wells (1980). Balemans (1974) gives a comprehensive list of guidelines for the safe design of chemical plant, drawn up in the form of a check list. A loss prevention check list is included in the Dow Fire and Explosion Index Hazard Classification Guide, Dow (1987). 

Figure 10-3 Form used in the Dow Fire and Explosion Index. The figures and tables referenced in the form are provided in the index booklet. Source Dow s Fire and Explosion Index Hazard Classification Guide, 7th ed., (1994). Reproduced by permission of the American Institute of Chemical Engineers.

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