Section 855.380  Building Protection

a)         A negative air pressure differential of at least 0.02 inches of water column, relative to outside ambient air pressure, shall be maintained at all times throughout the contained area during the asbestos abatement work to ensure that contaminated air in the work area does not filter back to uncontaminated areas.  Instrumentation (a monometer with a readable tape) for measuring pressure differential shall be provided by the contractor in accordance with OSHA regulations 29 CFR 1926.1101.

b)         Once the contained area is established, the negative pressure system shall operate continuously, 24 hours a day, from the start of the abatement work to final air clearance.

c)         Asbestos fiber levels in areas adjacent to the contained area shall not exceed 0.01 fibers per cubic centimeter of air (f/cc) or background levels, whichever is higher, as determined by phase contrast microscopy.  Work shall immediately cease in the area if  fiber counts in adjacent areas are found to exceed this amount.  Remedial action (e.g., wet cleaning) shall be taken to reduce such levels to those required by this Section.

d)         The contractor shall be responsible for cleanup of any adjacent areas which become contaminated as a result of the asbestos abatement activities.