Document ID: chunk:federal_register_of_legislation:F2016L00418:body:0:p45
Version: federal_register_of_legislation:F2016L00418
Segment Type: other
Provision Reference: 
Character Range: 116555–119459

If leaks or deficiencies are found during the initial testing of the enclosure, these must be rectified (an expandable foam sealant, tape or equivalent may be used) and another smoke test performed until no leaks or deficiencies are identified.
Following a visual examination of the enclosure and surrounding area, if a leak of asbestos (more than 0.02 fibres/ml) is detected:
    * the asbestos removal work must stop until any defects have been rectified
    * before work recommences, it is essential to:
       * identify the source of the leak/s
       * eliminate or minimise further release of airborne asbestos fibres
       * seal the leaks in the enclosure
       * re-test the enclosure by smoke testing until the enclosure is effective again
       * clean any contaminated areas
       * conduct visual inspections
       * conduct an air monitoring test specific to the incident (air monitoring)
       * notify the relevant authority where applicable
       * re-assess the boundaries of the asbestos removal  work area and site
A supply of expandable foam sealant, polyester insulation or equivalent should be kept on site for sealing leaks.

5.3 Information on pressure exhaust units (negative units)
To prevent the escape of airborne asbestos fibres from an enclosed removal work area, an exhaust extraction fan should be installed so as to create a 'negative' air pressure of approximately 12 Pa (water gauge) within the enclosed removal work area.
An exhaust extraction fan should be installed in the enclosure to create a 'negative' air pressure of approximately 12 Pa (water gauge) within the enclosed asbestos removal work area. This may require the use of more than one negative pressure exhaust unit.
Units should incorporate warning devices for filter integrity/overload and power failure, and should have a manometer or magnohelic gauge and an audible and visual alarm system.
The negative pressure exhaust unit should be positioned opposite the decontamination unit to enable laminar (smooth) air flow.
    * The air entering the asbestos removal work area passes through the decontamination unit or point-of-entry while the air extracted passes through a HEPA filter to remove any asbestos before it is discharged to the outside.
    * If this is not possible, consideration should be given to how to set up the enclosure, decontamination unit and negative pressure exhaust unit to enable optimum smooth flow of air through the enclosure so as to minimise dead air pockets. Discharge of the air from the enclosure should be at a location away from other working areas, air-conditioning inlets or breathing air compressors.
The HEPA filter must comply with AS 4260:1997 High efficiency particulate air (HEPA) filters – Classification, construction and performance or its equivalent.
    * A coarse pre-filter should be installed on the air intake side of the negative air unit