Historical Note: Subpart (§56-6.1) filed July 7, 1987 eff. July 28, 1987.
(a) Negative air pressure equipment. All large and small asbestos abatement projects shall employ negative air pressure equipment ventilation.
(b) Operation. The negative air pressure equipment shall operate continuously, 24 hours a day, from the start of the abatement work through the cleanup operations and clearance air monitoring.
(c) Negative air pressure. A negative air pressure, relative to areas outside of the enclosure, shall be maintained at all times in the work area during the asbestos abatement project to ensure that contaminated air in the work area does not filter back to an uncontaminated area.
(d) Ventilation units. If more than one primary ventilation unit is installed, the units shall be turned on one at a time and the integrity of wall barriers, for secure attachment or the need for additional reinforcement, shall be checked. Units connected in series shall be considered a single unit for this test. A minimum of one additional unit, having a capacity at least equal to that of the primary unit, shall be installed as a backup to be used during primary unit filter changing and upon primary unit failure.
(e) Power supply. A power supply shall be available to satisfy the requirements of the total of all ventilating units.
(f) Power failure. On electric power failure, abatement shall stop immediately and shall not resume until power is restored and exhaust units are operating fully. On extended power failure, longer than one hour, the decontamination facilities, after the evacuation of all persons from the work area, shall be sealed airtight.
(g) Air changes. Negative pressure ventilation equipment shall be installed and operated to provide at least four air changes in the work area every hour.
(h) Openings in enclosure. Openings made in the enclosure system to accommodate these units shall be made airtight with tape and/or caulking. Where possible, only the intake and the filter access panel shall remain within the work area to permit filter changing, while minimizing equipment contamination and the likelihood of contamination of nonwork areas.
(i) Installation and care. Negative pressure ventilation units shall be exhausted to the outside of the building or structure and away from occupied areas. Proper installation, air monitoring and daily inspections shall be conducted to insure that the ducts do not release asbestos into uncontaminated areas. Fans, ducts and joints shall comply with the following:
(1) Ducts, of at least equivalent shape and dimension as that of the negative pressure ventilation exhaust, shall be used to exhaust to the outside of the building or structure.
(2) Airtight system. All fans, ducts and joints shall be sealed, braced and supported to maintain an airtight system.
(j) Exhaust location. At no time shall the negative pressure ventilation unit exhaust within 50 feet of a receptor or adversely affect the air intake of the building/structure or other buildings/structures.
Historical Note: Sec. filed July 7, 1987; amd. filed Oct. 18, 1991 eff. Jan. 1, 1992. Amended (c),(i)(1).
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