Severity of Consequences

We can demonstrate the notions of risk and risk assessment using Figure 1.18. For a given probability of failure occurrence and severity of consequence, it is possible to map the general relationship of risk and what this means in terms of the action required to eliminate the risk. 

Allows judgement to be made concerning facilities and routes, for probable hazard and severity of consequences ... 

Risk analysis is an assessment of tlie likelihood (probability) of an accidental release of a hazardous material and tlie actual consequences that might occur, based on tlie estimated vulnerable zones. The risk analysis is a judgment of probability and severity of consequences based on tlie history of previous incidents, local experience, and tlie best available current technological information. It provides an estimation of ... 

The severity of consequences of human injury tliat may occur (acute, delayed, and/or clironic healtli effects), tlie number of possible injuries and deatlis, and tlie associated liigh-risk groups. 

The severity of consequences on critical facilities (e.g., hospitals, fire stations, police departments, communication centers). 

The severity of consequences of damage to property (temporary, repairable, permanent). 

Rank tlie results qualitatively on a basis of severity of consequences or perhaps quantitative calculations. 

As examples of engineering and administrative controls, the PSM Rule lists "appropriate application of detection methodologies to provide early warning of releases." For systems handling toxic materials, detection methodologies are generally mitigation systems that reduce the severity of consequences after an accident occurs. 

To fully comply with the PSM Rule, it may be necessary to include in the PrHA report an analysis of mitigation systems that are in place to reduce the severity of consequences of accidents. 

Quantitative evaluation of the severity of accident consequences is not required. However, the PrHA team must qualitatively evaluate the range of the possible employee safety and health effects. Such evaluation is generally made by discussing the severity of consequences of each scenario (see Section 4). 

The essence of the ASTM E 2012 approach is to determine incompatibility scenarios that could foreseeably occur by examining all possible binary combinations. It may be necessary to review a process by using a systematic method such as a process hazard analysis (PHA) to identify all incompatibility scenarios that have a significant likelihood of occurrence and severity of consequences. The same review can then be used to evaluate whether adequate safeguards exist or whether further risk reduction is warranted. 

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