Hazard reactivity

Chemical Reactivity - Reactivity with Water. Dissolves and forms a weak solution if nitric acid. The reaction is not hazardous Reactivity with Common Materials May corrode metals in presence of moisture Stability During Transport Stable Neutralizing Agents for Acids and Caustics Flush with water Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

Chemical Reactivity - Reactivity with Water Hot water may cause frothing. Reaction with cold water is slow and non-hazardous Reactivity with Common Materials No reaction Stability During Transport Stable Neutralizing AgerUs for Acids and Caustics Solid spills can usually be recovered before any significant reaction with water occurs. Flush area of spill with water Polymerization Very unlikely at ordinary temperatures, even in the molten state Inhibitor of Polymerization None. 

Many additional hazards result from the hazardous reactivity of combinations of chemicals. The open literature contains numerous lists of the reactivity of different types of chemical combinations. Table 4.3 presents examples of combinations of compounds which are known to be reactive. More complete discussions and lists of highly energetic chemical interactions are found in CCPS (1995d, especially Table 2.14), Yoshida (1987), Medard (1989), FEMA (Appendix D, ca. 1989), and Bretherick (1995). 

According to EPCRA, facilities should provide either an MSDS or a list of chemicals to the SERC, LEPC, and local fire department. If facilities choose to supply only a list, the list should include specific information including health hazards, fire hazards, reactivity hazards, and physical data for every chemical on the list. Although only a list is required, the additional requirements for specific information makes the submission of only a list a rare occurrence. The use of MSD sheets is one of the most commonly used tools to convey this information. 

Chemical plants contain a large variety of hazards. First, there are the usual mechanical hazards that cause worker injuries from tripping, falling, or moving equipment. Second, there are chemical hazards. These include fire and explosion hazards, reactivity hazards, and toxic hazards. 

Two substances which have no hazardous reactivity properties in themselves can become dangerous when mixed. Certain groups of chemicals are likely to react with common substances such as air, water, acids, alkalies, and metals. Information about the possibility of such reactions is available in manuals on hazardous chemical reactions [35, 61, 62]. Examples of substances having incompatibility hazards when mixed are shown on Table 2.14. Applications of CHETAH to mixture instability determination [63,64] and to binary incompatibility [65] have been published. 

Reactive hazard Reactive properties and physical conditions of a single chemical or mixture that have the potential to generate heat, energy, and gaseous byproducts that have the potential to do harm. 

Social Acceptance. Social acceptance of chemical plants is still an issue. This is due to the fact that big disasters have occasionally occurred (Bhopal, Seveso) and also because chemical plants smell, due to diffusive emissions of volatile components. Via process intensification the amount of chemically hazardous, reactive material can be reduced considerably, by which the size of an emission in the case of an explosion will be far less and the chance of an explosion itself reduced by the lowered hazardous, reactive content. 

An MSDS lists the hazardous chemical contents of a product, describes its health and safety hazards, and gives methods for its safe use, storage, and disposal. The MSDS also includes information on fire and explosion hazards, reactivity, first aid, and procedures for handling leaks and spills. 

To enable those who cannot directly conduct appropriate tests to understand necessary methodology so that they can successfully subcontract required evaluations to outside professional institutions. By doing so, it is expected that use of highly hazardous reactive chemicals can be decreased and reactive chemicals can be used under safer conditions. 

Although progress has been made in methods of evaluating hazards for self-reactive substances, further improvement is required on the international level. To insure safety, one needs to take the measures which are consider the best for each specific occasion. The flow chart shown in Fig.1.1 has been suggested by people involved with safety to evaluate whether new substances are hazardous reactive chemicals. 

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