The legal system for the assessment of odours in ambient air is laid down in the Guideline on Odour in Ambient Air - GOAA. In several studies, the connection between the odour pollution in residential areas expressed as odour frequencies per year and the associated degree of annoyance of residents was investigated. The GOAA provides the legal framework in licensing and monitoring procedures for all types of installations.

  This legal framework is linked with the measurement methods for odour emissions at the source (olfactometry) and for odours in the ambient air (field inspection with grid measurements) as well as with a dispersion model for calculating recognisable odours in ambient air. In the GOAA, a scientifically based exposure-impact relationship is translated into limit values for odours in ambient air that also take into account differences in the annoyance potential of different odours types. In this paper, a brief overview of the results of the various investigations is given.

   Chile is now undertaking the preparation of three odour regulations for: Swine's farms, the sea products processing plants and it has started the process of reviewing the emission standard for pulp mills. Carrying out regulatory processes to solve the issue of annoying odours is not an easy job, because it has different characteristics compared to the rest of the atmospheric pollutants.

   However, the development of normative processes in Chile has so far provided important learning instances for each of the obstacles that have had to be overcome. Thus, the main objective of this work is to disseminate three lessons learned from the odour standards development processes in Chile. The results of this work are expected to contribute to other normative processes that will be initiated, particularly in Latin American countries.