Shock sensitivity, reactive chemicals

Reactive and/or explosive chemicals are sometimes used or produced in chemical industry workplaces. Reactive chemicals are sensitive to either friction or shock, or they react in the presence of air, water, light, or heat. Explosive chemicals decomfX)se or bum very rapidly when subjected to shock or ignition. Reactive and explosive chemicals are extremely dangerous because they produce huge amounts of desttuctive heat and gas. 

Reactive Chemicals Reviews The process chemistry is reviewed for evidence of exotherms, shock sensitivity, and other insta-bihty, with emphasis on possible exothermic reactions. It is especially important to consider pressure effects— Pressure blows up people, not temperature The pumose of this review is to prevent unexpected and uncontrolled chemical reactions. Reviewers should be knowledgeable people in the field of reactive chemicals and include people from loss prevention, manufacturing, and research. 

Review of reactive chemicals test data for evidence of flamma-bihty charac teristics, exotherms, shock sensitivity, and other evidence of instability... 

Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials May ignite combustible materials such as wood Stability During Transport Heat-and-shock-sensitive crystals may separate at very low temperature during transport Neutralizing Agents for Acids and Caustics Not pertinent Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Case histories regarding reactive chemicals teach the importance of understanding the reactive properties of chemicals before working with them. The best source of data is the open literature. If data are not available, experimental testing is necessary. Data of special interest include decomposition temperatures, rate of reaction or activation energy, impact shock sensitivity, and flash point. 

Fluorine nitrate is shock sensitive, especially in liquid state. The liquefied material explodes when shaken vigorously or in contact with alcohol, ether, andine, or grease (Bretherick s Handbook of Reactive Chemical Hazards, 5th. Ed., P. Urhen (ed.) 1995, pp 1405-6, Oxford, UK Butterworth-Heinemann). The gas catches fire when mixed with ammonia or hydrogen sulfide. 

It is evident that we cannot describe a substance by saying that it is very explosive. We must specify whether it is sensitive to fire and to shock, whether it is really powerful or merely brisant, or both, whether it is fast or slow. Likewise, in the discussions in the present book, we must distinguish carefully between sensitivity, stability, and reactivity. A substance may be extremely reactive chemically but perfectly stable in the absence of anything with which it may react. A substance may be exploded readily by a slight shock, but it may be stable if left to itself. Another may require the shock of a powerful detonator... 

Review the reactive chemicals test data summaries for exotherms, shock sensitivity or other indicators of instability or energy release potential. 

The ease of occurrence of explosion for a self-reactive chemical may be judged by its shock sensitivity and its ability to propagate the explosion. The shock sensitivity of highly sensitive chemicals can be measured by the drop ball test described above. However, those chemicals whose hazard can be measured by the drop ball test are too sensitive for daily use. Different methods are needed for those chemicals which are not likely to explode in daily use to determine whether a substance can cause explosion under extraordinary conditions. 

Reactive hazard evaluations should be made on all new processes as well as existing processes on a periodic basis. There is no substitute for experience, good judgement, and good data when evaluating potential hazards. Reviews in process chemistry should include (a) reactions, (b) side reactions, (c) heat of reaction, (d) potential pressure buildup, and (e) intermediate streams. Reactive chemicals test data should be reviewed for evidence of flammability characteristics, exotherms, shock sensitivity, or other evidence of instability. Examine Planned operation of the process should be examined, especially for... 

Mr. Ellison is president of Cerberus Associates, Inc. and as a private consultant, has responded to both transportation and fixed facility hazardous material incidents throughout the state of Michigan. He has acted as incident commander, safety officer, and response specialist at scenes involving chemical fires, water reactive materials, and shock sensitive materials. He has provided chemical and biological counterterrorism training to members of hazardous materials (HazMat) teams, police Special Weapons and Tactics (SWAT) teams, and Explosive Ordinance Disposal (EOD) teams. 

EXPLOSION and FIRE CONCERNS combustible NFPA rating Health 3, Flammability 2, Reactivity 0 spontaneous explosive reactions with dibenzol peroxide, fluorine nitrate, nitrosal perchlorate, red fuming nitric acid, and tetranitromethane reacts violently with boron chloride, peroxyformic acid, fluorine, trichloronitromethane, acetic anhydride, chlorosulfonic acid, perchromates, oleum and n-halomides ignites on contact with sodium peroxide and water forms heat-or shock-sensitive explosive mixtures with hydrogen peroxide, nitromethane and 1 -chloro-2,3-epoxypropane reactions with ozone and perchloric acid form explosive products decomposition emits highly toxic fumes of NOx use alcohol foam, dry chemical, water spray, or carbon dioxide for fire-fighting purposes. 

EXPLOSION and FIRE CONCERNS flammable NFPA rating Health 1, Flammability 3, Reactivity 0 reacts with hydrogen peroxide and nitric acid to form a heat-and shock-sensitive explosive product ignites on contact with potassium tert-butoxide mixture with 2-propanol produces explosive peroxides during storage incompatible with chlorosulfonic acid and oleum flashback along vapor trail may occur use alcohol foam, carbon dioxide, and dry chemical for firefighting purposes. 

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