Interactive is a Modelica library whose goal is to facilitate the implementation of virtual labs based on Modelica models quickly and with little effort. Modelica is a free object oriented modeling language. The implementation of a virtual lab for air pollution control developed using Interactive 2.0 is discussed in this manuscript. This virtual lab has been developed to explain the dispersion of pollutants into the atmosphere to undergraduate students of Environmental Chemistry of the Universidad Nacional de Tucum´an (Argentina). Main aspects in the virtual lab development process are addressed in this discussion, including: 1) application of a systematic methodology to adapt any Modelica model into a description suitable for interactive simulation; 2) composition of the virtual lab view using Interactive. Additionally, the use of this virtual lab in the Environmental Chemistry course is discussed. Interactive is freely available at www.euclides.dia.uned.es.