Quantification of occupational risk owing to contact with moving parts of machines

► Logical model (bowtie) for quantifying the probability of contact with moving parts of machines. ► Quantification of the logic model. ► Risk rates for fatality, permanent and non-permanent injury. ► Measures to decrease fatality, permanent and non-permanent injury risk. Working population is often exposed to risks associated with moving parts of machines. In this paper a methodology for managing occupational risk owing to contact with moving parts while working with machines is presented. The methodology is based on the principles of quantified risk assessment. A logic model for contact with moving parts while working with machines has been developed under the Workgroup Occupational Model (WORM) project, financed by the Dutch government and is presented in this paper. Sixty-three other models have been developed to cover different hazards in all working activities. These models allow the delineation of accidents into sequences of events describing measures (technical and/or procedural) in place to prevent them or to mitigate their consequences. Identification of these sequences enables the identification of specific root causes of such accidents and hence the determination of specific and practical actions that can influence the probability of an accident. Quantification of these models provides, furthermore, a way for assessing the relative value of such measures and hence a basis for supporting decisions aiming at reducing the consequences of accidents in the work fields. Risk has been quantified for different working situations with machines such as operating, maintaining, cleaning and clearing a machine. Qualitative information on the safety functions, measures and barriers have been derived from the analysis of 766 actual accidents occurred and reported under the Dutch law over a period of 2years (1998–2000). A sensitivity analysis assessing the relative importance of measures affecting risk is presented and risk increase and risk decrease indices are assessed.