Safety Considerations Guide, Tricon v9.0 - Tuv-fs.com

Hazard and Risk Analysis 7Completion of a HAZOP determines the severity and probability of the risksassociated with a process. Risk severity is based on a measure of the anticipatedimpact or consequences, including:• On-site consequences• Worker injury or death• Equipment damage• Off-site consequences• Community exposure, including injury and death• Property damage• Environmental impact• Emission of hazardous chemicals• Contamination of air, soil, and water supplies• Damage to environmentally sensitive areasA risk probability is an estimate of the likelihood that an expected event will occur.A risk probability is classified as high, medium, or low, and is often based on acompany’s or a competitor’s operating experience.Several methods of converting HAZOP data into SILs are used. Methods rangefrom making a corporate decision on all safety system installations to morecomplex techniques, such as an IEC 61508 risk graph.Chapter 1Safety Concepts