(63c) How to Incorporate the Health, Safety and Environment Management System in Quantitative Risk Assessments

According to the risk involved in some facilities that process hazardous goods, it is mandatory to have a strong management system that includes Health, Safety and Enviroment (HSE) aspects implemented and certified. This is required by the shareholders and also international legislation like the Directive Seveso II in Europe. Strong evidence in the accident investigation in hazardous process industries show that 67% from the notified accidents were caused by management failures in HSE [1]. The HSE management has influence in consequence mitigation actions in Quantitative Risk Assessment (QRA), but are not taken in account in the risk calculation. Along the paper is showed a metodology based on a HSE audit program according to OHSAS 18000 . A model is established to link the correlation between the weight and the degree of implementation for each of the 16 audited elements checked in the audit program in order to have a correction factor applied to the equipment and systems failure rate used in the QRA.

The results are demonstrated in a real case where a QRA individual isorisk curve is ploted with failures rates taken from generic data banks like AIChE [2] and after the aplication of the correction factor taken from the present proposed model.

The model is also discussed in comparison with others methodologies [3] used to risk calculations like Risk Based Inspection [4] and failure data specialization with Bayesian inference [5].

References: [1] N.KAWA, C.KIRCHSTEIGER Technical note on the contribution of sociotechnical factors to accidents notified to MARS. Jounal of Loss Prevention in the Process Indutries 12, 53-57. 1999 [2] AIChE, ?Guidelines for Process Equipment Reliability Data with Data Tables?, Center for Chemical Process Safety (CCPS) [3] PAPAZOGLOU, I. A., & ANEZIRIS, O. On the quantification of the effects of organizational and management factors in chemical installations. Reliability Engineering Systems Safety, 63, 33?45, 1999. [4] API, (American Petroleum Institute), Risk Based Inspection Base Resource Document, API 581, 2001. [5] RIBEIRO, A., MELO, P.F., Impact of failure data specialization in quantitative risk assessment of process plants. 21st Annual CCPS ? AIChE International conference on process Safety Challenges in a Global Economy, 2006