Page:NIOSH Manual of Analytical Methods - 7400.pdf/2

 ASBESTOS and OTHER FIBERS by PCM: METHOD 7400, Issue 2, dated 15 August 1994 - Page 2 of 15

REAGENTS:

EQUIPMENT:

1.	 	Acetone,* reagent grade. 2.	 	Triacetin (glycerol triacetate), reagent grade.
 * See SPECIAL PRECAUTIONS.

1.	Sampler: field monitor, 25-mm, three-piece cassette with ca. 50-mm electrically conductive extension cowl and cellulose ester filter, 0.45to 1.2-µm pore size, and backup pad. NOTE 1:	Analyze representative filters for fiber background before use to check for clarity and background. Discard the filter lot if mean is ≥ 5 fibers per 100 graticule fields. These are defined as laboratory blanks. Manufacturerprovided quality assurance checks on filter blanks are normally adequate as long as field blanks are analyzed as described below. NOTE 2:	The electrically conductive extension cowl reduces electrostatic effects. Ground the cowl when possible during sampling. NOTE 3:	Use 0.8-µm pore size filters for personal sampling. The 0.45-µm filters are recommended for sampling when performing TEM analysis on the same samples. However, their higher pressure drop precludes their use with personal sampling pumps. NOTE 4:	Other cassettes have been proposed that exhibit improved uniformity of fiber deposit on the filter surface, e.g., bellmouthed sampler (Envirometrics, Charleston, SC). These may be used if shown to give measured concentrations equivalent to sampler indicated above for the application. 2.	Personal sampling pump, battery or linepowered vacuum, of sufficient capacity to meet flow-rate requirements (see step 4 for flow rate), with flexible connecting tubing. 3.	Wire, multi-stranded, 22-gauge; 1″ hose clamp to attach wire to cassette. 4.	Tape, shrink- or adhesive-. 5.	Slides, glass, frosted-end, pre-cleaned, 25- × 75-mm. 6.	Cover slips, 22- × 22-mm, No. 1½, unless otherwise specified by microscope manufacturer. 7.	Lacquer or nail polish. 8.	Knife, #10 surgical steel, curved blade. 9.	Tweezers.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition