Inherently Safer Design Strategies

Approaches to the design of inherently safer processes and plants have been grouped into four major strategies by IChemE and IPSG (1995) and Kletz (1984, 1991b)  

Minimize Use smaller quantities of hazardous substances (also called Intensification) 

Substitute Replace a material with a less hazardous substance 

Moderate Use less hazardous conditions, a less hazardous form of a material, or facilities which minimize the impact of a release of hazardous material or energy (also called Attenuation and Limitation of Effects). 

Simplify Design facilities which eliminate unnecessary complexity and make operating errors less likely, and which are forgiving of errors which are made (also called Error Tolerance). 

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These inherently safer design strategies are discussed in more detail in Chapter 3, and examples can also be found in Chapter 4, which discusses inherently safer design opportunities through the life cycle of a chemical process. 

Figure 2.Z. The relationship/ between ptrocess risk management and inherently safer design strategies.

Additional discussion regarding reactor design strategies is covered in Section 3.1 on minimization (as an inherently safer design strategy), and in Section 4.4 on Design and Construction. 

The discussion in the following sections is not comprehensive it is intended to provide examples. The inherently safer design strategy (see Section 2.6) used in most of the examples is Simf lify. 

Hazard and Risk Analysis Consideration should be given to identifying process hazards as early as possible in the process equipment design, so that measures can be taken to reduce or eliminate the hazards. Inherently safer design strategies, such as minimize, substitute, moderate, and simplify, should be implemented. 

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