NYC-WTC_000233286

NYC 9/11 Public Portal Document

allowed, unless the multiple types of ACM are part of the same system (e.g. floor tile/cove base and mastics, or ceiling/wall tile and mastic). Simultaneous removals are allowed on a project as long as they are within different regulated abatement work areas. (b) Requirements for Sequential Abatement. When multiple types of abatement work are done in a common regulated abatement work area or enclosure, a sequential order of abatement is required as shown below. (1) Initial Plasticizing. Initial plasticizing of the containment area shall be as required for the most stringent case of removal. (2) Sequential Removal. Sequential removal shall allow for only one type of removal of ACM at a time in a sequential order within the work area until that type of material is completely removed. Thereafter, another type of ACM can be removed within the same work area. Relief from plasticizing is for the surfaces to be abated only at the time of that specific material abatement. Other surfaces shall be plasticized as the material being abated dictate, except as noted below. (i) Order of Sequential Abatement. The following sequence of abatement within a work area shall begin at the ceiling or upper level and progress one material at a time down to the floor and from most friable material to least friable material.

(ii) Example: fa; First. All ceiling fireproofing, ceiling plaster or similar ceiling OSHA Class I friable material shall be completely abated so that no visible exposed ACM, PACM or asbestos material remains. Then the friable mechanical/tank insulation, isolation/ vibration damper material and thermal pipe, ducts, pipe fitting insulation, mudded firebrick, or similar OSHA Class I or Class II friable material shall be completely abated so that no visible exposed material remnants remain. Glovebags may be used. After all friable ACM has been abated, the area shall be cleaned of all debris/residue using HEPA vacuuming and wet wiping. Second. OSHA Class II non-friable materials shall be abated. If other areas were abated, no new plasticization shall be required. Ceiling and wall tiles, transite, interior window glazing, expansion joint, millboard and other NESHAP Category I and II non-friable ACM shall be abated so that no visible exposed material remnants remain and the area shall be cleaned of all debris/residue using HEPA vacuuming and wet wiping. (c) Last. OSHA Class II non-friable flooring abatement shall be last. Non-friable ACM flooring materials and ACM mastic shall be abated so that no visible exposed material remnants

12 NYCRR56 Subparts, Page 79

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NYC-WTC_000233365