Modern industrial processes tend to be technically complex, involve substantial energies, and have the potential to inflict serious harm to persons or property during a mishap.
The IEC 61508 standard defines safety as “freedom from unacceptable risk.” In other words, absolute safety can never be achieved; risk can only be reduced to an acceptable level.
Safety methods to mitigate harm and reduce risk include:
• Changing the process or mechanical design, including plant or equipment layout
• Increasing the mechanical integrity of equipment
• Improving the basic process control system (BPCS)
• Developing additional or more detailed training procedures for operations and
maintenance
• Increasing the testing frequency of critical components
• Using a safety-instrumented system (SIS)
• Installing mitigating equipment to reduce harmful consequences; for example,
explosion walls, foams, impoundments, and pressure relief systems
Reference: Triconex