3. Define the study perimeter

The study perimeter must be proportionate to the nature and scale of the project, and to its impact on the environment (in terms of both impact and potential hazards).

An initial approach can be based on the specific features of the planned plant and the characteristics of its environment.

However, as the project progresses, steps will be taken to adjust the perimeter, if necessary, in line with the results of the various studies, notably on atmospheric emissions, whether permanent or accidental, but also according to the results of the hazard study scenarios.