Encapsulation or removal of friable thermal and acoustic insulation

• Pages: 45-51

15. Encapsulation or removal of friable

thermal and acoustic insulation

15.1. Identification

15.1.1. Before the repair or replacement of thermal or acoustic insulation

thought to contain asbestos is planned, the presence and type of asbestos should be

positively identified.

15.2. Indications for removal

15.2.1. Asbestos insulation should be removed:

(a) when it is breaking away from the base; or

(b) when the insulation is likely to be abraded or otherwise damaged; or

(c) when the surface is very friable; or

(d) when the resultant concentration of airborne asbestos dust is above the exposure

limit.

15.3. Enclosure of the work area

15.3.1. Where dust is liable to escape from the work areas, all external openings

from the work area, including windows and doors, should be adequately sealed with

adhesive tape or isolated by sealed plastic sheeting to prevent the escape of asbestos

dust.

15.3.2. Where the work area forms only part of the building, it should be

enclosed or isolated by impervious plastic sheeting which is of adequate strength and

firmly supported.

15.3.3. Care should be taken to ensure that asbestos dust cannot escape at points

where pipes and conduits pass out of the working area.

15.3.4. (1) To prevent asbestos dust leakage, ventilation which maintains the

whole work area under negative pressure should be provided.

(2) The extracted air should pass through an appropriate filtration

mechanism before being exhausted to atmosphere.

15.3.5. Exit/entry airlocks should be constructed at points of access to the work

enclosure.

15.3.6. All entry points should carry prominently displayed warning notices

which forbid entry to anyone not wearing suitable protective equipment.

15.3.7. At the end of each work period, the air extraction equipment should

remain in operation for at least 15 minutes after stripping has ceased.

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