This handbook presents different aspects needed for evaluating odour exposure by using dispersion modelling to help the final user. This handbook applies to calculating the odour/odorant level in ambient air from odour emission sources; choosing appropriate odour models depending on a project's specific conditions, in particular, dealing with complex situations; selecting appropriate meteorology. understanding the dose-response criteria and how the Frequency-Intensity-Duration-Offensiveness-Sensitivity scheme fits in a result; and the preparation of an odour report based on the results of a model.eng