Minimization principle inherent safety

Understanding the chemistry of the process also provides the greatest opportunity in applying the principles of inherent safety at the chemical synthesis stage. Process chemistry greatly determines the potential impact of the processing facility on people and the environment. It also determines such important safety variables as inventory, ancillary unit operations, by-product disposal, etc. Creative design and selection of process chemistry can result in the use of inherently safer chemicals, a reduction in the inventories of hazardous chemicals and/or a minimization of waste treatment requirements. 

Storage and receiving are activities that can greatly contribute to a safe and economic operation. It is here that quality control can be achieved at minimal cost. Label verification and other quality assurance measures can increase the confidence level that the correct chemicals have arrived, thereby potentially circumventing the use of wrong chemicals. Wrongly shipped chemicals can be returned to the manufacturer with minimal or no cost to the batch operation owner. As with all processes and activities it is of great importance to apply the principles of inherent safety, in particular the minimization and attenuation principles (CCPS G- 41). 

In practice the main purpose of the process plant design is to minimize the total process risk for the limitation of effects. Here risk is the product of the probability of an incident to happen and the possible consequences of that incident. In this thesis the limitation of effects by the means of inherent safety principles is evaluated. 

Process control plays an important role in how a plant process upset can be controlled and subsequent emergency actions executed. Without adequate and reliable process controls, an unexpected process occurrence cannot be monitored, controlled and eliminated. Process controls can range from simple manual actions to computer logic controllers, remote from the required action point, with supplemental instrumentation feedback systems. These systems should be designed such as to minimize the need to activate secondary safety devices. The process principles, margins allowed, reliability and the means of process control are mechanisms of inherent safety that will influence the risk level at a facility. 

Hazardous substances released from plants could cause serious problems to plant employees as well as to the nearby public. The release could be due to accidents (human error), instrument failure, control failure, and natural calamities or through deliberate acts of vandalism, terrorism, or sabotage. The application of inherent security can help in two ways (1) by reducing the likelihood that a facility will be targeted and (2) by minimizing the severity of an incident should an attack occur. Similar to inherent safety principles, one can consider a set of guidelines for inherent security ... 

Eliminate and minimize the size of hazards using the principles of inherent safety design ... 

The primary philosophy is to follow the principles of inherent safety. This implies a systematic effort to apply the principles of hazard elimination, minimization/ intensification, hazard substitution, moderation/attenuation, and simplification. However, additional controls will still be required to control a hazardous situation, prevent escalation, and mitigate the risk to people, to the environment, asset, and reputation. Preferably, these safeguards will be passive- or active-engineered controls rather than administrative controls (i.e., dependent on direct human intervention). 

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