Risk mitigation engineering control measures

Containment is an engineering control measure, the second risk mitigation principle (see Sect. 26.7.1). It may be defined as a process or device to contain product, dust or contaminants in one zone, preventing it from escaping to another zone [2] or, to put it differently, the prevention of the escape of a substance. 

Integrity and safety involve application of prevention and mitigation measures to address the likelihood and consequence factors of risk, respectively. They can be classified broadly as engineering controls, people controls, and management controls. 

Layers of protection There are many independent layers of protection provided in the control measure in addition to the basic process control system. These layers of protection make the control measures more robust. Fig. 11/4.5.4-1 may be referred to for more detail. Detailed discussions are available in Chapter V. Common mode failure Common mode failure refers to the failure of more than one control system on account of a common cause, which underlines the importance of independent layers of protection. However, common cause can affect both engineering and administrative controls. So, while considering the adequacy of control measures used for risk prevention/reduction/mitigation, etc. it is necessary and important to see that all such control measures are not only independent but also do not suffer from common mode fculure—discussed in later part of the book. 

---