Purpose. The work involves the development of numerical models to assess the effectiveness of the air curtain usage near the building in the event of chemical pollution. Methodology. To describe the process of dispersion of a chemically hazardous substance, emitted in emergency situations, the three-dimensional equation of impurity mass transfer in atmospheric air is used. To calculate the air velocity field near the building in the presence of an air curtain, a potential-flow model is used. The modelling equations take into account the velocity field of the wind flow, atmospheric diffusion, and the intensity of the emission of a chemically hazardous substance into the atmosphere. For the numerical integration of the mass transfer equations, implicit difference schemes are used. The complex of programs was created to solve the problem of calculating pollution zones near buildings in the presence of an air curtain. The application of the developed model allows you to quickly calculate this field of concentration of a chemically hazardous substance near the building in the presence of an air curtain. Findings. Numerical models for calculating the aerodynamics of the air flow and the concentration field near the building when using an air curtain were constructed. They can be used to carry out operational calculations of the size, intensity of pollution zones, which are formed in the atmosphere during the emission of chemicals at industrial sites. The developed numerical models can be implemented on computers of low and medium power, which allows it to be widely used for solving problems in developing an emergency response plan (ERP). For practical application of the developed numerical models, standard input information is required. Authors present the results of a laboratory experiment. Originality. Effective three-dimensional numerical models are proposed for estimating the level of atmospheric air pollution when emission of chemically hazardous substances into the atmosphere and using an air curtain near an industrial building. Models allow you to quickly calculate the effectiveness of the air curtain usage. Practical value. The developed numerical models allow solving applied problems arising in the development of ERP for chemically hazardous objects.