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ASBESTOS and OTHER FIBERS by PCM 7400 <br /> FORMULA:Various MW:Various CAS:see Synonyms. RTECS:Various <br /> METHOD:7400,Issue 2 EVALUATION:FULL Issue 1:Rev.3 on 15 May 1989 <br /> Issue 2:15 August 1994 <br /> OSHA: 0.1 asbestos fiber(>5 µm long)/cc;1 f/cc,30 min PROPERTIES: solid,fibrous,crystalline,anisotropic <br /> excursion;carcinogen <br /> MSHA: 2 asbestos fibers/cc <br /> NIOSH:0.1 f/cc(fibers>5 µm long),400 L;carcinogen <br /> ACGIH:0.2 f/cc crocidolite;0.5 f/cc amosite;2 f/cc chrysotile <br /> and other asbestos;carcinogen <br /> SYNONYMS[CAS#1:actinolite [77536-66-4] or ferroactinolite [15669-07-5]; amosite [12172-73-5]; anthophyllite [77536- <br /> 67-51;chrysotile[12001-29-5];serpentine[18786-24-8];crocidolite[12001-28-4];tremolite[77536-68-61; <br /> amphibole asbestos[1332-21-41;refractory ceramic fibers[142844-00-6];fibrous glass <br /> SAMPLING MEASUREMENT <br /> SAMPLER: FILTER TECHNIQUE: LIGHT MICROSCOPY,PHASE CONTRAST <br /> (0.45-to 1.2-µm cellulose ester membrane, <br /> 25-mm;conductive cowl on cassette) ANALYTE: fibers(manual count) <br /> FLOW RATE*:0.5 to 16 Umin SAMPLE <br /> PREPARATION: acetone-collapse/triacetin-immersion <br /> VOL-MIN*: 400 L @ 0.1 fiber/cc method[21 <br /> -MAX*: (step 4,sampling) <br /> COUNTING <br /> *Adjust to give 100 to 1300 fiber/mM2 RULES: described in previous version of this <br /> method as W rules[1,31 <br /> SHIPMENT: routine(pack to reduce shock) <br /> EQUIPMENT: 1.positive phase-contrast microscope <br /> SAMPLE 2.Walton-Beckett graticule(100-µm field <br /> STABILITY. stable of view)Type G-22 <br /> 3.phase-shift test slide(HSE/NPL) <br /> BLANKS: 2 to 10 field blanks per set <br /> CALIBRATION: HSE/NPL test slide <br /> ACCURACY <br /> RANGE: 100 to 1300 fibers/mm2 filter area <br /> RANGE STUDIED: 80 to 100 fibers counted <br /> ESTIMATED LOD: 7 fibers/mm'filter area <br /> BIAS: see EVALUATION OF METHOD <br /> PRECISION(Sr): 0.10 to 0.12[1];see EVALUATION OF <br /> OVERALL PRECISION(S):0.115 to 0.13[11 METHOD <br /> ACCURACY: see EVALUATION OF METHOD <br /> APPLICABILITY:The quantitative working range is 0.04 to 0.5 fiber/cc for a 1000-L air sample.The LOD depends on sample <br /> volume and quantity of interfering dust,and is<0.01 fiber/cc for atmospheres free of interferences.The method gives an <br /> index of airborne fibers.It is primarily used for estimating asbestos concentrations,though PCM does not differentiate <br /> between asbestos and other fibers.Use this method in conjunction with electron microscopy(e.g.,Method 7402)for assis- <br /> tance in identification of fibers.Fibers<ca.0.25 µm diameter will not be detected by this method[4].This method may be <br /> used for other materials such as fibrous glass by using alternate counting rules(see Appendix C). <br /> INTERFERENCES:If the method is used to detect a specific type of fiber,any other airborne fiber may interfere since all <br /> particles meeting the counting criteria are counted.Chain-like particles may appear fibrous.High levels of non-fibrous dust <br /> particles may obscure fibers in the field of view and increase the detection limit. <br /> OTHER METHODS:This revision replaces Method 7400,Revision#3(dated 5/15/89). <br /> NIOSH Manual of Analytical Methods(NMAM),Fourth Edition <br />