The aim of this report is to provide guidance for how to calculate risk areas on the basis of the results of different dispersion models. Dispersion models are intended to describe the distribution of chemicals in the environment for example after a chemical accident. With these results, we can predict the risk of health effects in the public at various examples of disasters where people may be exposed to toxic industrial chemicals or chemical warfare agents. In assessing the effects of exposure to substance toxicity and route of exposure, exposure time and dosage must be taken into account. A probit function is being used in order to describe the relationship between exposure and casualty assessment. The probit function assumes that the toxic effect does not increase linearly with increasing dose. In this report only exposure from inhalation is considered. When calculating this casualty assessment, there is a number of different uncertainty factors to consider (referred as risk area 1). Risk area 1 mostly involves susceptible individuals who are more likely to get injured after exposure of selected chemicals and nerve gases. What is new in this report is that these uncertainty factors have been excluded to hopefully narrow a more credible hazardous risk zone (referred as risk area 2) than risk area 1. The industrial chemicals chosen for this report are acrylonitrile, ammonia, bromine, ethylene oxide, phosgene, chlorine, nitrogen dioxide, sulfur dioxide, hydrogen cyanide, hydrogen fluoride, hydrogen chloride and hydrogen sulfide. The chemicals are chosen based on the scale of production, handling, storage, and transport in Sweden. Nerve agents selected for this project are sarin, soman and VX. These are classified as weapons of mass destruction in UN Resolution 687. The current report is part of the project "Effektmodeller", which is a summary of the results of the project's C-section.