Risk assessment criteria

Hence risk assessment criteria must be established so that there can be developed a national priority list of the hazardous sites that require remedial action. EPA has adopted the Mitre Model for assessing the risks and ranking waste sites. There is some criticism of this model, and there are a number of as yet unanswered questions about its application. Formal cost/benefit analysis will not be used, and risk assessment will be on a case-by-case basis. EPA will thus be developing its knowledge base and procedures as it carries out the program. 

The proposed NCP recognizes the statutory mandate in Section 105(8) to develop risk assessment criteria and a National Priority List by limiting "remedial" actions to releases on the National Priority List ( 300.67(a)). This will put teeth in the mandate of Section 105(8) and will assure the importance of the risk analy-sis/prioritization process. 

Vogel points in part to the difference in the criteria for estabhshing regulations. In general, the U.S. regulations had a sound science basis. For Europe, there was a shift to a precautionary principle. It relies more readily on public fears and perceived risks. The risk assessment criteria differ. For the United States, if there is no proof for a risk, there is little justification for regulating them. The risk should be allowed. For Europe, if there is a chance for a risk, it should not be allowed. 

Scope, Boundary Definition and Risk Assessment Criteria... 

Although not mandatory in the HAZOP method, this study comprised a risk assessment to all deviations detected. Risk assessment was performed through the use of a risk matrix already used in similar industries which included the combination of probability (possibility that the event occurs) and severity (as a consequence of the event). For the risk assessment criteria, four levels of probability were defined very unlikely/remote, likely/possible, probable and frequent. For severity were defined also four levels reduced, moderate, high, very high/catastrophic. The designation of risk parameters took into account the probability of occurrence, the measures implemented, historical events, potential injury to persons, to materials, to the environment. The combination between the four levels lead to four types of risk, grouped in two levels, acceptable/not significant, which even... 

Since the first edition, more emphasis has been placed on the use of risk management concepts. We have long held that when the JHA process incorporates risk-assessment criteria within its hazard analysis, it becomes the foundation for effective implementation of a safety system s elements. 

Table 3.1 is a representative matrix that combines hazard severity and hazard probability, so that risk assessment criteria may be applied to determine the acceptance of the risk, or to identify the need for corrective action by means of redesign, procedural instructions, or other means, to eliminate or reduce the risk to an acceptable level. 

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