Asbestos abatement Sampling & Analysis. Abatement Project Supervision

Transcription

1 Asbestos abatement Sampling & Analysis Abatement Project Supervision

2 TOPICS FOR DISCUSSION Air Sampling PERSONNEL AREA Analysis PCM Analysis TEM Analysis

3 TYPES OF SAMPLING Two types of air sampling are conducted on an asbestos abatement project: Personnel Sampling required by OSHA Area sampling required by EPA (AHERA), NYSDOL and NYCDEP

4 Air Sampling Devices Personal Sampling Pump High Volume Sampling Pump with Sampling Stand Air Sampling Cassettes

5 Air Sampling OSHA Two reasons we run air samples for OSHA compliance: 1) To protect unprotected workers in the workplace 2) To validate respirator choice (protection factor) (This sampling is the Abatement Contractor s responsibility.)

6 Air Sample Cassette Sampling Pump Worker Wearing Personal Air Sampling Device Air Sample Cassette In The Breathing Zone

7 AREA SAMPLING Both New York State and New York City asbestos regulations require air monitoring: prior to the project, during work area preparation, during abatement activities, and and for final clearance.

8 AREA AIR SAMPLING PRE-ABATEMENT Also called BACKGROUNDS DURING ABATEMENT POST ABATEMENT Also called POST TEST OR CLEARANCE

9 PRE-ABATEMENT SAMPLING - Backgrounds: Inside and Outside the proposed Work area. - Air samples collected prior to commencement of abatement activities represent fiber concentrations which occur in the air during normal activities. - 5 samples inside the Work Area, 5 samples outside the Work Area.

10 DURING SAMPLING These Samples are collected during the preparation or set-up of the Work Area and decontamination units and daily until the completion of the removal and cleaning activities.

11 DURING SAMPLING The collection of air samples during abatement is important to all parties involved. The documentation of fiber concentrations determines if the contractor provided adequate engineering controls, work practices, and maintained barriers in order to prevent the release of fibers to outside the work area.

12 DURING SAMPLING These are obtained daily from a variety of locations; outside critical barriers, decontamination units, floors above/below. The Locations often change daily to make sure all areas outside the containment have been checked for increased fiber levels, if any.

13 DURING SAMPLING If air samples collected outside the regulated abatement work area indicate airborne fiber concentrations at or above ( ) 0.01 fibers per cubic centimeter (f/cc), or the established background level, whichever is greater, work shall stop immediately for inspection and repair of barriers and negative air ventilation systems.

14 DURING SAMPLING At no time during the project should airborne levels be higher than the levels acceptable for work area re-occupancy. If the work stoppage criteria is exceeded, State and City regulations mandate the clean up of surfaces outside of the regulated abatement work area using HEPA-vacuums and wet-cleaning methods be performed prior to resumption of preparation, abatement or cleaning activities.

15 CLEARANCE SAMPLING Final clearance sampling is conducted at the completion of abatement and cleanup activities; and after visual inspections are conducted, but before any isolation and critical barriers are removed.

16 CLEARANCE SAMPLING Final clearance sampling is conducted at the conclusion of abatement procedures and after at least three separate cleanings of the work area have been performed. This sampling will help to determine if the contractor removed the asbestos and cleaned the area properly, and if the area is acceptable for building occupants to reenter.

17 CLEARANCE SAMPLING As opposed to the passive or stationary sampling done for background/preabatement and daily sampling, final clearance sampling requires the Air Sampling Technician to perform an aggressive technique. Prior to final clearance sampling, the area must be clean, free of all visual dust and debris, dry, and have visual inspections before aggressive sampling can begin.

18 CLEARANCE SAMPLING

19 CLEARANCE SAMPLING - 5 inside the work area - 5 outside the work area - 2 blanks (1 open/1 sealed)

20 CLEARANCE LEVEL - Project Clearance Sampling Targets - < 0.01 f/cc or the background levels, whichever is higher - (samples are NOT averaged).

21 Air Sampling Calibration Every pump must be calibrated before and after its use. Calibration is an industrial hygiene standard and a regulatory requirement.

22 Air Sampling Calibration Typical Field Rotometers

23 Rotometer Being Used to Calibrate Pump

24 ANALYSIS - Two Types of Microscopy used: - Phase Contrast Microscopy (PCM) - NIOSH 7400 Method - Transmission Electron Microscopy (TEM) - Employs X-rays to yield a diffraction pattern and X-ray Spectra to definitively identify asbestos fibers as well as non-asbestos particles

25 PCM vs. TEM PCM Counts all fibers (including fiberglass, plant and carpet fibers, and others) Operates at 400X for fiber counting Also used for OSHA compliance (personal samples) and for all other air samples during the project TEM Specific for asbestos fibers Typically operated at 20,000X Small fiber size is irrelevant; it can see all airborne asbestos ( µm) Required for most AHERA-related final clearance

26 PCM Analysis

27 PCM Analysis Sample Prep

28 PCM Analysis PCM Microscope PCM view of fibers (400X)

29 TEM Analysis Fiber Chemistry (EDS) TEM Sample Grid Fibers magnified ~20,000X Diffraction Pattern (SAED)