Page:NIOSH Manual of Analytical Methods - 7404.pdf/2

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CELLULOSE INSULATION: METHOD 7404, Issue 1, dated 15 March 2003 - page 2 of 6
REAGENTS: EQUIPMENT:
1. Colloidal Graphite.* 1. Sampler: field monitor, 25-mm, three- piece cassette with ca. 50-mm electrically conductive extension cowl and polycarbonate filter, 0.45- to 1.2-um pore size, and backup pad.
* (See SPECIAL PRECAUTIONS.) NOTE 1: Analyze representative filters for fiber background before use. This is needed when field blanks contain fibers.
NOTE 2: The electrically conductive extension cowl reduces electrostatic effects. Ground the cowl when possible during sampling.
2. Personal sampling pump, battery or line-powered vacuum, of sufficient capacity to meet flow rate requirements (see step 4), with flexible connecting tubing.
3. Microscope, scanning electron, operated at 15Kv with viewing screen having an inscribed or overlain calibrated scale.
4. Tape, shrink- or adhesive-.
5. Tweezers.
6. 25-mm carbon disk planchets.
7. Colloidal graphite paint.
8. Grounding wire, 22-gauge, multi strand.
9. Sputter coater.


SPECIAL PRECAUTIONS: Colloidal graphite contains isopropanol, which is flammable. Take precautions not to ignite it. Use only in well ventilated area.

SAMPLING:

  1. Calibrate each personal sampling pump with a representative sampler in line.
  2. Fasten the (uncapped) open-face cassette to the worker’s lapel. The open face should be oriented downward. Wrap joint between extender and monitor body with tape to keep the joint clean and prevent contamination when disassembled. Where possible, especially at low %RH, attach sampler to electrical ground to reduce electrostatic effects during sampling.
  3. Submit at least 2 field blanks (or 10% of total samples, whichever is greater) for each set of samples. Remove top covers from field blank cassettes and store top covers and cassettes in a clean area (e.g., a closed bag or box) during sampling. Replace top covers when sampling is completed.
  4. Sample at 1L/min.
    NOTE: If the cellulose insulation is being applied dry, sample for a shorter period time than if the application is wet. Obtain two personal samples per worker. Sample at same flow rate but for different durations. A minimum duration of 1 minute is appropriate for very dusty environments. The longer duration should be determined by the overall dustiness, size of the area being insulated and other factors as well.
  5. At the end of sampling, replace top cover and end plugs.
  6. Ship samples with conductive cowl attached in a rigid container with packing material to minimize jostling or damage.
NOTE: Do not use untreated polystyrene foam in the shipping container because electrotatic forces may cause fiber loss from sample filter.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition

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