Maintenance of Decontamination Enclosure Systems and Workplace Barriers

Section 855 Section 855.440  Maintenance of Decontamination Enclosure Systems and Workplace Barriers a)         Following completion of the construction of all polyethylene barriers and decontamination system enclosures, the contractor, or his designated representative, and project manager shall allow  a minimum of six hours settling time to ensure that barriers will remain intact and secured to walls and fixtures before beginning actual abatement activities.  The negative air pressure equipment shall be in operation during this settling time. b)         All polyethylene barriers inside the work area, in the worker decontamination enclosure system, and in the equipment decontamination enclosure system, and partitions constructed to isolate the work area from occupied areas, shall be inspected by the contractor and project manager at least twice daily.  The barriers shall be inspected before the start of and following the completion of the day's abatement activities.  Inspections and observations shall be documented in all project log books. c)         Damage and defects in the enclosure system shall be repaired upon discovery. d)         Smoke tubes shall be used by the contractor to test the effectiveness of the work area barrier system before abatement work begins and at least once a day thereafter until the work is completed.  The project manager shall observe the test.  Results and observations shall be documented in all project log books. e)         At any time during the abatement activities after barriers have been erected, if visible emissions are observed outside of the work area or if damage occurs to barriers, work shall stop, repairs shall be made to the barriers, and visible residue cleaned up using appropriate HEPA vacuuming and wet mopping procedures prior to resuming abatement activities. f)         The contractor shall HEPA vacuum or wet clean the equipment decontamination enclosure system and the entire worker decontamination enclosure system at the end of each day of abatement activities. g)         If air samples collected outside of the work area during abatement activities indicate airborne fiber concentrations greater than original background levels or 0.01 f/cc as determined by PCM, work shall stop for inspection and repair of barriers.  Cleanup of surfaces outside of the work area using HEPA vacuums or wet cleaning techniques shall be done.  Air sampling shall indicate a fiber concentration less than background levels, or below 0.01 f/cc as determined by PCM, prior to resuming abatement activities. (See Section 855.340(b)(2)(B)(iii).) h)         Negative pressure ventilation equipment shall be installed and operated to provide a minimum of four air changes in the work area every hour.  Openings made in the enclosure system to accommodate these units shall be made airtight with tape and/or caulking.  If more than one ventilation unit is installed, units shall be turned on one at a time while checking the integrity of wall barriers for secure attachment and the need for additional reinforcement.  A power supply shall be available to satisfy the requirements of the ventilating units.  Negative pressure ventilation units shall be exhausted to the outside of the building away from occupied areas.  Twelve inch extension ducting shall be used to reach from the work area to the outside of the building when ducting is required.  Careful installation, air monitoring and daily inspections by the contractor and project manager shall be done to insure that the ducting does not release fibers into uncontaminated building areas. i)          Once constructed and reinforced, and with negative pressure ventilation units in operation, worker and equipment decontamination enclosures shall be tested for leakage by the contractor, utilizing smoke tubes.  The project manager shall observe these tests.  Enclosures shall be repaired or reconstructed as needed.  Results and observations shall  be documented in all project log books. j)          The contractor shall identify and maintain emergency and fire exits from the work area.