Oil Mist, Mineral (5026)
OIL MIST, MINERAL Cn H2n+2 where n $ 16
MW: not pertinent
METHOD: 5026, Issue 2
5026
CAS: 8012-95-1
EVALUATION: FULL
OSHA : 5 mg/m3 NIOSH: 5 mg/m3 ; STEL 10 mg/m3 ACGIH: 5 mg/m3 (as sampled by a method which does not collect vapor)
RTECS: PY8030000 Issue 1: 15 August 1987 Issue 2: Rev.: 15 May 1996
PROPERTIES: liquid; d 0.8 to 0.9 g/mL @ 20 °C; BP 360 °C; vapor pressure negligible
SYNONYMS: airborne mist of white mineral oil or the following water-insoluble petroleum-based cutting oils: cable oil; cutting oil; drawing oil; engine oil; heat-treating oils; hydraulic oils; machine oil; transformer oil
SAMPLING SAMPLER:
FLOW RATE:
MEASUREMENT
MEMBRANE FILTER (37-mm diameter, 0.8-:m MCE, 5-:m PVC, 2-:m PTFE, or glass fiber)
TECHNIQUE:
INFRARED SPECTROPHOTOMETRY
ANALYTE:
mineral oil
1 to 3 L/min
EXTRACTION:
10 mL CCl4
IR SCAN:
3200 to 2700 cm-1 vs. blank CCl4
CALIBRATION:
standard solutions of mineral oil in CCl4
RANGE:
0.1 to 2.5 mg per sample
3
VOL-MIN: -MAX:
20 L @ 5 mg/m 500 L
SHIPMENT:
routine
SAMPLE STABILITY:
stable
ESTIMATED LOD: 0.05 mg per sample [3]
BLANKS:
2 to 10 field blanks per set
PRECISION ( þ r ):
0.05 [3]
ACCURACY RANGE STUDIED:
2.5 to 11.7 mg/ m3 [1] (100-L samples)
BIAS:
- 0.84% [1,2]
OVERALL PRECISION (Ö rT ): 0.065 [1] ACCURACY:
± 11.8 %
APPLICABILITY: The working range is 1 to 20 mg/m3 for 100-L air sample. This method is applicable to all trichlorofluoroethane-soluble mineral oil mists, but not to (nor does OSHA’s standard cover) semi-synthetic or synthetic cutting fluids. INTERFERENCES: Any aerosol (e.g., tobacco smoke) which absorbs infrared radiation near 2950 cm-1 interferes.
OTHER METHODS: This revises P&CAM 283 [3]. P&CAM 159 [4] and S272 [5] use similar samplers with measurement by fluorescence spectrophotometry. These methods have not been revised because of limited applicability (i.e., not all mineral oils contain fluorescent components and other fluorescent compounds interfere). Infrared analysis overcomes both of these limitations.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition OIL M IST, MIN ERA L: MET HO D 502 6, Issue 2, Rev. 15 M ay 1996 - Page 2 of 4 EQUIPMENT:
REAGENTS: 1. Carbon tetrachloride* (CCL4), reagent grade. 2. Stoc k m ineral oil standards , 20 m g/m L. W eigh 1.0 g of the bulk m ineral oil sam ple into a 50-m L volum etric flas k. D ilute to volume with CCl4. Prepare in duplicate.
- See SPECIAL PRECAUTIONS
1. Sam pler: mem brane filter, 37-mm , 0.8-:m MCE, 5-:m PV C, 2-:m PT FE, or glass fiber filter, with cellulose backup pad in two-piece filter cassette. NOT E 1: High concentrations of oil mist may plug m em brane filters. Glass fibers filters have a higher capacity for oil mist and mem brane filters. NOT E 2: Hand le filters carefully with tweezers to avoid contam ination by skin oil. 2. Personal sa m pling pum p, 1 to 3 L/m in, with flexible connecting tubing. 3. Infrared spectrophotometer, doulble beam, dispersive, with scanning capability in the 32002700 cm -1 region, and two 10-m m spe ctrop hoto m eter c ells, infrared q uartz w ith PT FE sto ppers m ounte d in dem ounta ble cell holders. NOTE: Sta ndard glass cells m aybe used if infrared quartz cells are not available. 4. Vials, scintillation, 20-mL, with foil-lined or PT FE -lined c aps .* 5. Volum etric flas ks, 10-, 25-, an d 50 -m L.* 6. Volum etric pipet or reag ent dispense r, 10-m L.* 7. Pipets, 2- to 250-:L. 8. Tweezers.
- Rinse glassware with CCl4. Air dry.
SPECIAL PRECAUTIONS: Carbon tetrachloride is a suspected human carcinogen. Handle in a fume hood.
SAMPLING: 1. Calibrate each personal sampling pump with a representative sampler in line. 2. Sam ple at a n ac curately kn own flow ra te in the rang e 1 to 3 L/m in for a total sam ple size of 20 to 500 L. NOTE: High concentrations of oil mist may plug membrane filters creating unacceptably high pressure drops. If this occurs, terminate sampling. 3. Collect 5 to 10 m L of unuse d, undiluted mineral oil in a vial. Subm it with sam ples for standard preparation.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition OIL M IST, MIN ERA L: MET HO D 502 6, Issue 2, Rev. 15 M ay 1996 - Page 3 of 4 SAMPLE PREPARATION: 4. Using tweezers, transfer each sample or blank filter to a vial. Add 10.0 mL CCl4. Cap and shake vigorously.
CALIBRATION AND QUALITY CONTRO L: 5. Calibrate daily with at least six working standards. a. Add known amounts of stock mineral oil standard to CCl4 in 10-m L volum etric flas ks and dilute to the mark to obtain mineral oil concentrations in the range 5 to 250 µg/mL. b. Analyze with samp les and blanks (step 8). c. Prepare calibra tion gra ph (p eak abs orba nce vs. :g m ineral oil). 6. Determine recovery (R) at least once for each lot of filters used for sampling in the range of interest. Prepare three filters at each of five levels plus three media blanks. a. De pos it a known am oun t of stock m ineral oil standard o nto the filter. Allow solve nt to evaporate. b. Store samples overnight in filter cassettes. c. Prepare and analyze with working standards. d. Prepare a graph of R vs. µg mineral oil recovered. 7. Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graph and R g raph are in control.
MEASUREMENT: 8. Scan each standard solution and each blank or sample filter extract from 3200 to 2700 cm -1 in absorbance mode vs. CCl4 in reference beam. Record absorbance at wavelength of largest absorbance near 2940 cm -1 (± 11.8% ).
CALCULATIONS: 9. Determine the mass, µg (corrected for R), of mineral oil found in the sample (W ) and in the average media blank (B) from the calibration graph. 10. Calculate concentration, C, of mineral oil in the air volume sam pled, V (L)
EVALUATION OF METHOD: The sam pling portion of this m etho d wa s evaluated over the ran ge 2 .5 to 11 .7 m g/m 3 at 22 °C and 755 m m Hg using 100-L air samples of Gulf machine cutting oil with measurem ent by fluo rescence spectrophoto m etry. Mixed cellulose ester filters, 0.8-µm pore size, were used for sampling [1,5]. The overall precision was 0.065 with an average recovery of 98%. The infrared measurem ent method was subsequently evaluated by NIOSH [2,3]. Precision and ac curacy of the infrared and fluoresce nce spe ctrophotom etric techniques are sim ilar.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition OIL M IST, MIN ERA L: MET HO D 502 6, Issue 2, Rev. 15 M ay 1996 - Page 4 of 4 Issue 1 of this method (dated 8/15/1987) used Freon 113 as the solvent. However, since Freons are known atm ospheric ozo ne depleters, c arbon tetrachloride, the orig inal solvent used in P&CAM 283, is again specified, althou gh it is a s usp ecte d hu m an c arcinogen. PTFE filters (e.g. G elm an Ze fluor) als o m ay be used to sam ple oil mists. They have lower blanks than PVC, since PTFE has fewer extractables with CCl4 than other mem brane filters.
REFERENCES: [1] [2] [3] [4] [5]
Docum entation of the NIOSH Validation Tests, S272, U.S. Department of Health, Education, and W elfare , Pub l. (NIO SH ) 77-185 (197 7), available a s PB 274 -248 from NT IS, Sp ringfield, VA 22161. Bolyard, M L. Infrared Quantitation of Mineral Oil Mist in Personal Air Samples, AIH Conference, Hous ton, TX (19 80). NIOSH M anual of Analytical Methods, 2nd ed., Vol. 4, P&CAM 283, U.S. Department of Health, Educa tion, and W elfare, Publ. (NIOSH ) 78-175 (197 8). Ibid., Vol. 1, P&CAM 159, U.S. Department of Health, Education, and W elfare, Publ. (NIOSH) 77-157-A (1977). Ibid., Vol. 3, S272, U.S. Depa rtmen t of Health, Education, and W elfare, Publ. (NIOSH ) 77-157-C (1977).
METHOD REVISED BY: Charles Lorberau and Robert Glaser, NIOSH/DPSE.
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition