WORK AREA PREPARATION
Historical Note: Subpart (§§56-8.1 - 56-8.3) filed July 7, 1987 eff. July 28, 1987.
(a) Vacating of work area. The work area shall be vacated by the occupants prior to work area preparation and until satisfactory clearance air-monitoring results have been achieved.
(b)Signs. Caution signs shall be posted at all locations and approaches to a location where airborne concentrations of asbestos may exceed ambient background levels. Signs shall be posted that permit a person to read the sign and take the necessary protective measures to avoid exposure.
(c) Electric power. Shut down and lock out electric power to all work areas. The contractor shall provide temporary power and lighting and ensure safe installation of temporary power sources and equipment used where high humidity and/or water shall be sprayed in accordance with all applicable codes. All power to work areas shall be brought in from outside the area through a ground-fault interrupter at the source.
(d) Start of project-enclosure installation or construction. The personal decontamination enclosure system shall be installed or constructed prior to preparatory work in the work area, and in particular before the disturbance of asbestos material. The waste decontamination enclosure system shall be installed or constructed prior to commencement of abatement activities.
(e) Heating, ventilating and air conditioning (HVAC) system isolation. Acceptable methods for HVAC system isolation shall include:
(1) Shutdown and isolation. Shutdown and isolation of HVAC systems to prevent contamination and asbestos dispersal to other areas of the building or structure.
(2) Local isolation Local isolation and provision for temporary HVAC.
(3) Positive pressurization Positive pressurization of the HVAC system.
(i) Positive pressurization shall be restricted to circumstances where HVAC must service the remainder of the building or structure and the HVAC equipment is in the work area or the ducts run through the work area. The appropriate HVAC duct and plenum outlets, inlets and exhaust dampers shall be sealed with sheathing and caulking, covered with a double layer of at least six-mil fire-retardant plastic sheeting and taped airtight. The HVAC duct and plenum joints shall be taped air-tight. The mixing and balancing damper positions shall be altered and the return fan(s) shall be shut down to produce the required positive pressures. The supply fan(s) shall be placed in a manual "on" position to prevent shutdown by fail-safe mechanisms.
(ii) Project phasing, climate conditions, load conditions and HVAC equipment limitations and controls shall be considered when this alternate procedure is evaluated. Aerodynamics in the duct system, particularly spurs or trunks, shall be considered and, if necessary, the ducts/dampers shall be altered or removed to prevent loss of positive pressure in any part of the system. Precautions shall be taken during abatement activities to insure that the ducts, seals and static pressure lines are not damaged.
(iii) The presence of positive pressure shall be demonstrated on a daily basis by testing. Air sampling in occupied, downstream, nonwork areas shall be performed on a daily basis as per the requirements of section 56-17.3(a) of this Part. Positive pressure differential verification between the work area and nonwork areas shall be done on a continuous basis. The differential pressures shall be easily verifiable by use of leak-free, rigid, static pressure taps, static lines on the supply and return ducts, and static lines originating in the work area, adjacent areas, or downstream nonwork areas.
(f) HVAC filters and ducts. Contaminated HVAC filters shall be handled and disposed of as asbestos waste material. The ducts and filter assembly shall be wet-cleaned and/or HEPA- vacuumed where system air samples and/or dust samples indicate asbestos contamination.
(g) Movable objects. Movable objects within the work area shall be precleaned using HEPA-filtered vacuum equipment and/or wet cleaning, and such objects shall be removed from the work area to an uncontaminated location. Upholstered furniture and drapes shall be HEPA- vacuumed twice before removal from the work area. Carpeting shall be HEPA-vacuumed twice and cleaned before removal from the work area. If disposed of as asbestos waste material, cleaning is not required. If carpeting is left in place, it shall be covered with one-half-inch thick sheathing prior to required plasticizing.
(h) Fixed objects. Fixed objects, and other items which are to remain within the work area, shall be precleaned using HEPA-filtered vacuum equipment and/or wet cleaning. Such objects and items shall be enclosed with two layers of at least six-mil fire-retardant plastic sheeting and sealed with tape.
(i) Precleaning. The work area shall be cleaned using HEPA-filtered vacuum equipment and/or wet cleaning. Methods that raise dust, such as dry sweeping or vacuuming with equipment not equipped with HEPA filters, shall be prohibited. Asbestos material shall not be disturbed during precleaning.
(j) Isolation barriers - general. Isolation barriers that seal off all openings, including but not limited to windows, corridors, doorways, skylights, ducts, grilles, diffusers and any other penetrations of the work area, shall be constructed using two layers of at least six-mil fire- retardant plastic sheeting sealed with tape. Also, all seams in system components that pass through the work area shall be sealed. Doorways and corridors which shall not be used for passage during work shall also be sealed.
(k) Isolation barriers - specific. Separation of the work area from the remainder of the work site by construction of isolation barriers shall be accomplished as follows:
(1) Wall construction. Walls shall be constructed of wood or metal framing to support barriers in all openings larger than 32 square feet, except where any one dimension is one foot or less.
(2) Sheathing thickness. A sheathing material of at least 3/8 -inch thickness shall be applied to the work side of the barrier.
(3) Sealing of partitions. Edges of the partition shall be caulked at the floor, ceiling, walls and fixtures to form an airtight seal.
(4) Plastic sheeting. The work area side of the partition shall be covered with a double layer of at least six-mil fire-retardant plastic sheeting with staggered joints and sealed.
(5) Plasticizing/sealing. All floor, wall and ceiling surfaces shall be covered with a minimum of two layers of at least six-mil fire-retardant plastic sheeting. The floor shall be plasticized first, and its plastic sheeting shall extend up the walls a distance of at least 12 inches on all sides. The walls shall then be plasticized by applying plastic sheeting from ceiling to floor, thus overlapping the floor sheeting by at least 12 inches. This process shall be repeated for the second layer of plastic sheeting for the floor and walls. All seams within a layer shall be separated by a distance of at least six feet and sealed airtight. All seams between layers shall be staggered.
(l) Removal of mounted objects. After isolation barriers are in place, objects such as light fixtures, electrical tracks, alarm systems, ventilation equipment and other items not previously sealed, shall be removed and HEPA-vacuumed. Localized HEPA-filtered vacuum equipment shall be used during fixture removal to reduce asbestos dispersal.
(m) Removal of ceilings. Suspended ceiling tiles and T-grid components contaminated with asbestos material shall remain in place until the work area has been plasticized and personal and equipment decontamination enclosures have been constructed. The tiles and components shall then be removed and disposed of as asbestos waste.
(n) Exits. Emergency and fire exits from the work area shall be maintained or alternate exits shall be established according to all applicable codes.
(o) Boiler areas. When abatement is to be performed within a boiler room, boilers shall be shut down and the burner and boiler accesses and breechings shall be sealed until abatement is completed and satisfactory clearance air-monitoring results have been achieved.
(p) Elevator shutdown or isolation. Elevators running through the work area shall be shut down except as noted in this subdivision.
(1) Isolation - detail. In projects where the elevator cannot be shut down, the hoist-way door frames shall be enclosed with nominal 2ft. x 4ft. framing, 16 inches center-to-center, covered with5/8-inch sheathing, preferably plywood or similar building material, and caulked at all seams. The enclosures shall be covered with two seamless layers of at least six-mil plastic sheeting, taped and sealed airtight. A final larger layer of at least six-mil plastic sheeting shall be taped airtight, but with slack, forming a larger perimeter diaphragm to sense air movement caused by the elevator operation.
(2) Elevator shaft ports. Elevator shaft ports, for pressure equalization when within the work area, shall be vented to the outside or nonwork areas using oversized solid-walled ducts or chambers constructed of a minimum of 3/8-inch sheathing over nominal 2ft. x 4ft. framing, 16 inches center-to-center. The joints shall be caulked and the ducts or chambers shall be sealed with two layers of at least six-mil fire-retardant plastic sheeting and duct tape. The first layer of plastic sheeting shall be attached to the ducts or chambers using a spray adhesive. This system shall be subjected to and pass a negative pressure test daily.
(q) Toilet facilities. Adequate toilet facilities shall exist, either in the clean area of the personal decontamination enclosure or shall be readily accessible to the personal decontamination enclosure.
Historical Note: Sec. filed July 7, 1987; amds. filed: Oct. 18, 1991; Oct. 25, 1994 eff. Nov. 9, 1994. Amended (d).
(a) Timing - removal of salvage. Removal of nonporous, nonmovable salvage from a full or partial demolition with asbestos material in evidence shall occur after isolation barriers and decontamination enclosures are in place in that portion of the building or structure, and only after the salvage has been wet-cleaned and/or HEPA-vacuumed.
(b) Flooring. On demolition projects, flooring shall be made watertight.
(c) Chimney effects. On demolition projects, all chimney effects in stacks, columns, flues, shafts and double-walled enclosures shall be eliminated by sealing the accesses.
(d) Specific requirements. Demolition projects shall comply with section 56-8.1(a)-(f) and (i)-(q) of this Subpart.
(e) Enclosure projects. Prior to the placement of isolation barriers, surfaces to be enclosed shall be cleaned using HEPA-filtered vacuum equipment and/or wet cleaning.
Historical Note: Sec. filed July 7, 1987 eff. July 28, 1987.
(a) Vacation of work areas. All project areas shall be vacated by the occupants prior to work area preparation and until full abatement has been achieved.
(b) Isolation of work area. The project area shall be isolated by cordoning it off with barrier tape or line and shall be accessible through only one entrance/exit.
(c) Signs. Caution signs shall be posted at any location and approaches to a location wherever airborne concentrations of asbestos may exceed ambient background levels. Signs shall be posted that permit a person to read the sign and take the necessary protective measures to avoid exposure.
Historical Note: Sec. filed July 7, 1987; amd. filed Oct. 18, 1991 eff. Jan. 1, 1992.
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