Law Department notice on WTC document preservation, Oct 2001

NYC 9/11 Public Portal Document

completion of post-cleaning verification procedures by the Environmental Cleaning Contractor (see 8.2 of this document).

7.4.1 Encapsulant coatings shall be applied directly to the interior porous surfaces of ventilation system components by hand brushing, rolling, or troweling, or via spray system, with a maximum distance of 24" from the spray discharge tip to the surface being treated. Encapsulant coatings may not be fogged into the system. A continuous film thickness should be achieved in treated areas, as per manufacturer's instructions.

7.4.2 Ventilation system control devices, heating elements, sensing equipment, grilles, and fans must be adequately blocked off or masked so that they will remain free from over-spray from the Encapsulation process.

7.5 Service openings: All access ways cut in the ventilation system for inspection and/or cleaning must be repaired so that they shall not significantly alter the airflow or adversely impact the facility's indoor air quality. All openings made in the ventilation system must be sealed in accordance with industry standards and local codes, using materials acceptable under those standards and codes (see Appendix B).

7.6 Disposal of Debris: All waste and debris removed from the ventilation system shall be double­ bagged in 6-mil polyethylene bags and disposed of in accordance with all applicable federal, state, and local requirements.

8.0 QUALITY ASSURANCE

8.1 Health and Safety: The ventilation system/duct cleaning firm shall comply with all applicable federal, state, and local requirements for protecting the safety of the ventilation system/duct cleaning firm's employees, building occupants, and the environment. No processes or materials shall be employed in such a manner that they will create adverse health effects to the building occupants, the ventilation system/duct cleaning firm's employees, or the general public.

8.1.1 The ventilation system/duct cleaning firm shall perform initial exposure monitoring of its employees for asbestos and lead in accordance with 29 CFR 1910. 1001 and 29 CFR 1910.1025, respectively. 8.1.2 Ventilation system/duct cleaning firm's employees shall use respiratory protection in compliance with OSHA 1910.134

8.1.3 Regardless of exposure assessment results, at minimum the ventilation system/duct cleaning firm’s employees shall wear properly fitted, HEPA-filtered (P-100) negative half-mask respirators when performing any work related tasks on site which might expose them to elevated levels of airborne particulate.

8.2 Post-cleaning Verification: Prior to re-commissioning a cleaned section of the ventilation system (at the end of the work shift, etc.), the ventilation system/duct cleaning firm will obtain cleanliness clearance from the Environmental Cleaning Contractor. Ventilation system cleanliness will be determined after mechanical cleaning and before the application of any surface treatment or introduction of any treatment-related substance to the ventilation system. Verification shall be conducted before the ventilation system is restored to normal operation.

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NYC-WTC_000145211