Inherent safety review, chemical reactivity

Inherently safer process checklist, 167-172 Inherent safety review, chemical reactivity hazard management, 22-23 Initiation, management practices, 65-71. See also Management practices Insulated exotherm test, chemical reactivity tests, 87... 

The first major objective for the inherent safety review is the development of a good understanding of the hazards involved in the process. Early understanding of these hazards provides time for the development team to implement recommendations of the inherent safety effort. Hazards associated with flammability, pressure, and temperature are relatively easy to identify. Reactive chemistry hazards are not. They are frequently difficult to identify and understand in the lab and pilot plant. Special calorimetry equipment and expertise are often necessary to fully characterize the hazards of runaway reactions and decompositions. Similarly, industrial hygiene and toxicology expertise is desirable to help define and understand health hazards associated with the chemicals employed. 

Experience has shown that reactive chemistry hazards are sometimes undetected during bench scale and pilot plant development of new products and processes. Reactive chemistry hazards must be identified so they can be addressed in the inherent safety review process. Chemists should be encouraged and trained to explore reactive chemistry of "off-normal operations. Simple reactive chemicals screening tools, such as the interactions matrix described in Section 4.2, can be used by R D chemists. 

During the development of a new facility or process, or when introducing a new process into an existing facility for the first time, an inherent safety review can be conducted to understand the chemical reactivity hazards and explore hazard reduction alternatives. The review need not be limited to chemical reactivity hazards. It can be used to address all other types of process hazards at the same time, including flammability/ combustibility dust or mist explosibility elevated or reduced pressures or temperatures phase differences and health hazards such as toxicity, corrosivity, and asphyxiation. 

An inherent safety review should be conducted by a multidisciplinary team. For new facilities, the inherent safety review is an excellent opportunity to begin to involve those persons likely to have line responsibility for the facility that will need to deal with the chemical reactivity hazards... 

Section 4.1). For existing facilities, operating and maintenance personnel should also participate in the inherent safety review. A smaller team may be appropriate for facilities such as warehouses. In any case, the review team must include one or more individuals with the background and experience to recognize and understand the chemical reactivity hazards and how they may lead to uncontrolled chemical reactions. In this regard, outside experts may need to be consulted. 

Many issues in one management area are bound to affect performance in other areas. For example, an inherent safety review may propose a change in the process chemistry that will allow a definite reduction in chemical reactivity hazards, perhaps by eliminating a reactive intermediate. Such changes will have to fit with product quality requirements, and the customer may need to be included in the process of changing to the inherently safer alternative. Effective communication among all parts of the management team will avoid many problems and help identify what works best. 

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