NYC-WTC_000233286

NYC 9/11 Public Portal Document

(longer than one hour), after evacuation of all persons from the regulated abatement work area, the decontamination system enclosure facilities shall be sealed airtight. (8) Air Changes. Negative air pressure ventilation equipment shall be installed and operated continuously to provide at least four (4) air changes in the regulated abatement work area every hour including during clearance air sampling. (9) Openings in Enciosure. Openings made in the enclosure system to accommodate these units shall be made airtight with duct tape or caulking or both. Where possible, the intake side of the negative air ventilation unit shall remain within the regulated abatement work area to permit filter changing, while minimizing equipment contamination and the likelihood of contamination of non-work areas. (10) Installation and Care. Proper installation procedures, including use of appropriate filters and manufacturer’s recommended operating procedures shall be followed. (i) Each HEPA filter should be individually tested and certified by the manufacturer to have an efficiency of not less than 99.97% when challenged with 0.3 micron particles. Testing shall be in accordance with accepted methodologies, and each filter should bear an appropriate UL label to indicate ability to perform under specified conditions. (ii) Negative pressure HEPA filtered ventilation units shall be exhausted to the outside of the building or structure and away from public access and to a controllable area. (iii) Air sampling at exhaust duct termination locations and daily inspections shall be conducted to insure that procedures are followed to maintain the negative pressure air ventilation filtration systems. (iv) Pre-filters, secondary filters and HEPA-filters shall be replaced when dirty. (V) Ducts of at least equivalent shape and dimension as those of the negative pressure ventilation exhaust shall be used to exhaust to the outside of the building or structure. (vi) Booster Exhaust Fans shall be installed as required in this Section, and operated to maintain adequate flow from HEPA-filtered ventilation units to the exhaust duct termination locations. (vii) All fans, ducts and joints shall be sealed, braced and supported to maintain an airtight system. (viii) Once installed and operational, daily inspections shall be conducted to insure the airtight integrity of the system, and the findings shall be documented by the asbestos abatement

12 NYCRR56 Subpart?, Page 62

CITY_21MC100_0 03235082

NYC-WTC_000233348