Prior to any restitution of the area and prior to the removal of any total or partial containment device, the employer shall carry out :
1° An examination including all areas likely to have been polluted;
2° Thoroughly clean the area by vacuuming with equipment fitted with a high-efficiency filtration system;
3° A measurement of the dust level, carried out in accordance with article R. 1334-25 of the Public Health Code;
4° the fixation of any residual fibres on the treated parts.