In order to ensure that asbestos fibres are not dispersed into the environment around the work site and adjacent premises, the employer shall check compliance with the value set in Article R. 1334-29-3 of the Public Health Code by measuring dust levels:
1° In the area approaching the work area ;
2° In the recovery area
3° At points in the building in which the work is being carried out;
4° Near extractors in the area where they are discharged;
5° At the perimeter of the work site for work carried out outside.