NYC-WTC_000233286

NYC 9/11 Public Portal Document

56-7.8 Engineering Controls. (a) Negative Air Pressure Equipment. All OSHA Class I, Class III, and interior Class II asbestos abatement projects shall employ negative air pressure equipment ventilation. (1) Operation. The negative air pressure equipment shall operate continuously, 24 hours a day. from startup of negative air pressure equipment , through the cleanup operations and satisfactory clearance air sampling results being obtained, or the asbestos project is complete. (2) Timing of Instaiiation. The negative air ventilation units shall be installed and made operational after the critical barriers and isolation barriers are installed. (3) Negative Air Pressure. A negative air pressure, relative to areas outside of the enclosure, shall be maintained at all times in the regulated abatement work area during the asbestos abatement project to ensure that contaminated air in the regulated abatement work area does not escape back to an uncontaminated area. (4) Manometer. A manometer shall be used to document the pressure differential for all OSHA Class I large and small size asbestos project regulated abatement work areas. A minimum of -0.02 column inches of water pressure differential, relative to pressure outside the regulated abatement work area, shall be maintained within the regulated abatement work area, as evidenced by manometric measurements. Once installed, on a daily basis at least twice per workshift, the asbestos abatement contractor’s supervisor shall document the manometer reading within the daily project log. The manometer shall be installed and made operational once the negative air has been established in the regulated abatement work area. Magnahelic manometers shall be at a minimum calibrated semi-annually, and a copy of the current calibration certification shall be posted at the work site during Phase II operations. (5) Ventilation Units. If more than one primary HEPA-filtered ventilation unit is installed, the units shall be turned on one at a time and the integrity of wall barriers checked for secure attachment or the need for additional reinforcement shall be checked. Units connected to unfiltered booster fans in series shall be considered a single unit for this test. A minimum of one additional unit having a capacity of at least equal to that of the primary unit shall be installed, with unfiltered booster fans as applicable, as a backup unit to be used upon primary unit failure, or if necessary during primary unit filter changes. (6) Power Supply. A GFCI protected temporary power supply shall be available to satisfy the requirements of the total of all ventilation units. (7) Power Failure. In the event of electric power supply failure, abatement shall stop immediately and shall not resume until power is restored and exhaust units are operating fully. In the event of extended power failure

12 NYCRR56 Subpart?, Page 61

CITY_21MC100_0 03235081

NYC-WTC_000233347