Modelling the dispersion of a toxic substance at a workplace

The occupational health and safety of the workers in chemical plants are of great importance because they are exposed to concentrations of toxic substances that may exceed institutional limits. This work presents a methodology of assessing the indoor dispersion of the toxic chemical substance Vinyl Chloride Monomer (VCM) in a Polyvinyl Chloride (PVC) chemical plant using Computational Fluid Dynamics (CFD) techniques. A mathematical model using the CFD Code PHOENICS based on solving the full 3-D NaviereStokes and scalar conservation equations together with turbulence modelling is used to predict the toxic VCM dispersion in a geometrically complex industrial area. The source emissions, as well as the effect of the geometrical details of the building structure were also studied. The results showed that the use of a CFD is a promising technique to study the occupational exposure in the known carcinogen VCM and to design the proper ventilation system to reduce the consequences of an accidental release of VCM in a workplace.