Handling chemical reactivity hazard

Introduction Chemical reactivity is the tendency of substances to undergo chemical change. A chemical reactivity hazard is a situation with the potential for an uncontrolled chemical reaction that can result directly or indirectly in serious harm to people, property, or the environment. A chemical reaction can get out of control whenever the reaction environment is not able to safely absorb the energy and products released by the reaction. The possibility of such situations should be anticipated not only in the reaction step of chemical processes but also in storage, mixing, physical processing, purification, waste treatment, environmental control systems, and any other areas where reactive materials are handled or reactive interactions are possible. 

Reactive Chemistry Reviews The process chemistry is reviewed for evidence of exotherms, shock sensitivity, and other instability, with emphasis on possible exothermic reactions. The purpose 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. The CCPS Essential Practices for Managing Chemical Reactivity Hazards provides a useful protocol for identifying chemical reactivity hazards (Johnson et ah, 2003). A series of questions about the chemical handling operations and the materials are used to determine if there are possible reactivity hazards. Figure 23-18 summarizes the CCPS protocol for identifying reaction hazards. 

It is not necessary or desirable to create a separate system for managing chemical reactivity hazards if an appropriate management system is already in place. All management system essentials (see Table 4.1 in Chapter 4) apply to the management of other process hazards as well, such as the handling of toxic or flammable materials. Most apply to other essential practices as well, such as environmental management, occupational safety, and industrial hygiene. 

Whether or not chemical reactivity hazards are present is a function not only of each chemical s reactivity (by itself and in combination), but also of various extrinsic factors i.e., factors that are not intrinsic properties of the chemicals being handled. As the design for a facility progresses, decisions will be made regarding these factors that will affect the magnitude of the chemical reactivity hazards and the potential consequences if their control is lost. A partial list of extrinsic factors includes ... 

A person familiar with the chemical and physical properties of materials handled in the facility, as well as their chemical behavior under both normal and upset conditions this is especially important for facilities with chemical reactivity hazards. 

Multiple facilities in an organization may have similar chemical reactivity hazards similar storage, handling or processing operations or use similar technologies to control the associated hazards. If so, it may be more efficient for a corporate office or personnel to assume responsibility for some improvement activities such as auditing and research. This can also facilitate communication of incidents and best practices between facilities. 

The answers to Questions 7 through 11 will likely determine whether chemical reactivity hazards are present. For example, a jar of liquid ether that is a peroxide former may be brought to the facility for incineration. If it had been stored a long time and the contents had been exposed to air, unstable peroxides may be present that could explode when handled or fed to the incinerator. The information in Section 3.3 may be helpful in identifying whether any reactive chemicals are present. 

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