If a hazardous event takes place and a person calls rescue personnel, they should be able to estimate possible effects and the distances they may appear in only with the information provided. This thesis discusses four types of hazardous events involving flammable fluids. The focus is on their effects on people and structure in the form of heat radiation and pressure waves. When an accident is simulated the so called source terms (such as the release rate) are not known. However, these parameters have a relevant impact on the effects. Hence, they should not be neglected and are considered in this thesis. The aim is to obtain an output sufficient to estimate three risk zones (based on critical exposition values) from as little input data as possible and simplified formulae (no iterations). The four scenarios considered are BLEVEs, jet fires, pool evaporation/fires and vapour cloud fires/explosions. Due to a lack of data from past events, especially if it comes to the distances of the effects, the transferability of the results is potentially limited.