Operations were divided into 6 phases/working steps, for a total of 3 months and an average of 35 specialised workers, all of them holding an asbestos training certification.
The intervention was demanding, as the reclamation had to be carried out without interrupting the activities in the plant.
It is worth mentioning how this reclamation has been organised, as this shows an important difference from the Italian regulation: a risk analysis was mandatory for asbestos powder emission during the realisation of reclamation operations in the worksite. In Italy, modifications to the law have been discussed for a long time; something similar could be decided in our country too.
The obligation to assess dustiness levels (the measurement of the concentration of asbestos fibres per litre of air) caused by the activities in the work site was introduced in France by the Decree no. 2012-639 of 4th May 2012. Before starting the reclamation of the site, a testing worksite should be set up to allow the classification of every process which will be used for the reclamation of materials containing asbestos into 3 dustiness levels defined by the law, according to article R. 4412-98 of the above-mentioned decree.
There are 3 levels:
- level 1 - less than 100 fibres/litre in the workstation (analysis carried out using the META method)
- level 2 - between 100 and 6,000 fibres/litre in the workstation (analysis carried out using the META method)
- level 3 - between 6,000 and 25,000 fibres/litre in the workstation (analysis carried out using the META method)
Each level corresponds to a reclamation method which is more and more complex according to the level of exposure.
The remediation process of materials contained in the Isoroy plant correspond to the code M 05_T 01_ME 04a_C 02_A 03_H 01, which is specific for asbestos-containing materials, such as felt and cardboard. The assessment in our Working Plan shows an expected release of fibres of level 2 (on the basis of previous experiences).
The test carried out in the worksite, specific for one out of the six areas the operations are divided into, resulted in a level 1 exposure situation, with the release of less than 100 fibres/litre in the workstation. This would have entailed a modification of the work plan and a simplification of remediation activities, but the Client decided to keep the higher safety level and confirmed the method defined in the existing work plan.
In short, all the areas not containing asbestos - such as walls, offices, machineries and pipes - were confined and covered with a double 200 micron polythene sheet. Linoleum was laid on the ground to allow higher soil resistance. Openings and air leak points in the roof were sealed with polyurethane foam. 3-phase decontamination unit for waste and materials taken out of the contaminated area. 5-phase decontamination unit for the staff. two to eight 50,000 m3/h air extractors to ensure at least 6 exchanges/hour in each one of the six work site sub-areas, according to their dimension.