§ 1-91 Engineering Controls.
RCNY § 1-91
The following procedures shall be followed during the conduct of abatement activities on asbestos projects: (a) All asbestos projects shall utilize negative pressure ventilation equipment.
(1)On all asbestos projects, a manometer shall be used to document the pressure differential. The manometer shall be installed and made operational once the negative pressure has been established in the work area. Magnahelic manometers shall be calibrated at least every six months, and a copy of the current calibration certification shall be available at the work site.
(b)The negative pressure ventilation equipment shall operate continuously, 24 hours a day, from the establishment of isolation barriers through successful clearance air monitoring. If such equipment shuts off, adjacent areas shall be monitored for asbestos fibers.
(c)A static negative air pressure of 0.02 inches (minimum) water column shall be maintained at all times in the work place during abatement to ensure that contaminated air in the work area does not filter back to uncontaminated areas.
(d)If more than one ventilation unit is installed, units shall be turned on one at a time while checking the integrity of all barriers for secure attachment and the need for additional reinforcement.
(e)A dedicated power supply for the negative pressure ventilating units shall be utilized. The negative air equipment shall be on a ground fault circuit interrupter (GFCI) protected circuit separate from the remainder of the work area temporary power circuits.
(f)If the containment area of an asbestos project covers the entire floor of the affected building, or an area greater than 15,000 square feet on any given floor, the installation of a negative air cut off switch or switches shall be required at a single location outside the work place, such as inside a stairwell one floor below the lowest floor containing a work place, or at a secured location in the ground floor lobby when conditions warrant (such as when the work place is in a basement or below). The required switch or switches must be installed by a licensed electrician, pursuant to a permit issued by the Department of Buildings. If negative pressure ventilation equipment is used on multiple floors the cut off switch must be able to turn off the equipment on all floors.
(g)On loss of negative pressure or electric power to the negative pressure ventilating units, abatement shall stop immediately and shall not resume until power is restored and negative pressure ventilation equipment is operating again. When power failure or loss of negative pressure equipment lasts or is expected to last longer than one-half hour: (1) the make-up air inlets shall be sealed airtight, and (2) the decontamination systems shall be sealed airtight after the evacuation of workers and/or authorized visitors from the work area, and (3) all adjacent areas shall be monitored for asbestos fiber concentration upon discovery of, and subsequently throughout, the power failure.
(h)Negative pressure ventilation equipment shall be installed and operated to provide at least one air change in the work area every 15 minutes. Where there are no floor or wall barriers because floor or wall material is being abated, there shall be at least one air change in the work area every ten minutes.
(i)Openings made in the isolation barrier to accommodate these units shall be made airtight. The units shall remain within the work area unless located securely outside the building.
(j)Negative air pressure equipment shall be in compliance with ANSI Z9.2 (2012), Local Exhaust Ventilation.
(k)Negative air pressure systems shall be operated in accordance with "Specifications and Operating Procedures for the Use of Negative Pressure Systems for Asbestos Abatement, Guidance for Controlling Asbestos-Containing Materials in Buildings", EPA Report Number 560/5-85-024 (1985).
(l)Negative pressure ventilation equipment shall be exhausted to the outside of the building away from occupied areas.
(2)Negative pressure ventilation equipment shall exhaust away from areas accessible to the public.
(3)All ducting must be sealed and braced or supported to maintain airtight joints. Ducts must be reinforced and must be installed so as to prevent breakage. Damage to ducts must be repaired immediately and air monitoring must be conducted in the affected space.
(m)Where ducting to the outside is not possible, a second negative pressure ventilation unit compatible with the primary unit's capacity shall be connected in series. The area receiving the exhaust shall have sufficient, non-recycling exhaust capacity to the outside of the structure, and must be a normally non-occupied area.
(n)Careful installation shall be done to ensure that the ducting does not release fibers into uncontaminated building areas.
(o)Routine smoke testing and daily inspection must be performed by the Asbestos Handler Supervisor to ensure that the ducting does not release fibers into uncontaminated building areas. (Amended City Record 12/7/2018, eff. 1/6/2019; amended City Record 1/15/2025, eff. 2/14/2025)
