# Particulates Not Otherwise Regulated, Total (0500)

OSHA: 15 mg/m³ NIOSH: no REL ACGIH: 10 mg/m³, total dust less than 1% quartz PROPERTIES: contains no asbestos and quartz less than 1%
SYNONYMS: nuisance dusts; particulates not otherwise classified
SAMPLING
SAMPLER: FILTER (tared 37-mm, 5-µm PVC filter)
FLOW RATE: 1 to 2 L/min
VOL-MIN: 7 L @ 15 mg/m³
-MAX: 133 L @ 15 mg/m³
SHIPMENT: routine
SAMPLE STABILITY: indefinitely
BLANKS: 2 to 10 field blanks per set
BULK SAMPLE: none required
ACCURACY
RANGE STUDIED: 8 to 28 mg/m³
BIAS: 0.01%
OVERALL PRECISION ( ): 0.056 [1]
ACCURACY: ±11.04%
MEASUREMENT
TECHNIQUE: GRAVIMETRIC (FILTER WEIGHT)
ANALYTE: airborne particulate material
BALANCE: 0.001 mg sensitivity; use same balance before and after sample collection
CALIBRATION: National Institute of Standards and Technology Class S-1.1 weights or ASTM Class 1 weights
RANGE: 0.1 to 2 mg per sample
ESTIMATED LOD: 0.03 mg per sample
PRECISION (S$_1$):0.026 [2]
APPLICABILITY: The working range is 1 to 20 mg/m³ for a 100-L air sample. This method is nonspecific and determines the total dust concentration to which a worker is exposed. It may be applied, e.g., to gravimetric determination of fibrous glass [3] in addition to the other ACGIH particulates not otherwise regulated [4].
INTERFERENCES: Organic and volatile particulate matter may be removed by dry ashing [3].
OTHER METHODS: This method is similar to the criteria document method for fibrous glass [3] and Method 5000 for carbon black. This method replaces Method S349 [5]. Impingers and direct-reading instruments may be used to collect total dust samples, but these have limitations for personal sampling.
* Sampler: 37-mm PVC, 2- to 5-µm pore size membrane or equivalent hydrophobic filter and supporting pad in 37-mm cassette filter holder.
* Personal sampling pump, 1 to 2 L/min, with flexible connecting tubing.
* Microbalance, capable of weighing to 0.001 mg.
* Static neutralizer: e.g., Po-210; replace nine months after the production date.
* Forceps (preferably nylon).
* Environmental chamber or room for balance (e.g., 20 °C ± 1 °C and 50% ± 5% RH).
SPECIAL PRECAUTIONS: None.
PREPARATION OF FILTERS BEFORE SAMPLING:
* Equilibrate the filters in an environmentally controlled weighing area or chamber for at least 2 h. NOTE: An environmentally controlled chamber is desirable, but not required.
* Number the backup pads with a ballpoint pen and place them, numbered side down, in filter cassette bottom sections.
* Weigh the filters in an environmentally controlled area or chamber. Record the filter tare weight, W$_1$ (mg).
** Zero the balance before each weighing.
** Handle the filter with forceps. Pass the filter over an antistatic radiation source. Repeat this step if filter does not release easily from the forceps or if filter attracts balance pan. Static electricity can cause erroneous weight readings.
* Assemble the filter in the filter cassettes and close firmly so that leakage around the filter will not occur. Place a plug in each opening of the filter cassette. Place a cellulose shrink band around the filter cassette, allow to dry and mark with the same number as the backup pad.
SAMPLING:
* Calibrate each personal sampling pump with a representative sampler in line.
* Sample at 1 to 2 L/min for a total sample volume of 7 to 133 L. Do not exceed a total filter loading of approximately 2 mg total dust. Take two to four replicate samples for each batch of field samples for quality assurance on the sampling procedure.
SAMPLE PREPARATION:
* Wipe dust from the external surface of the filter cassette with a moist paper towel to minimize contamination. Discard the paper towel.
* Remove the top and bottom plugs from the filter cassette. Equilibrate for at least 2 h in the balance room.
* Remove the cassette band, pry open the cassette, and remove the filter gently to avoid loss of dust. NOTE:If the filter adheres to the underside of the cassette top, very gently lift away by using the dull side of a scalpel blade. This must be done carefully or the filter will tear.
CALIBRATION AND QUALITY CONTROL:
* Zero the microbalance before all weighings. Use the same microbalance for weighing filters before and after sample collection. Maintain and calibrate the balance with National Institute of Standards and Technology Class S-1.1 or ASTM Class 1 weights.
* The set of replicate samples should be exposed to the same dust environment, either in a laboratory dust chamber [7] or in the field [8]. The quality control samples must be taken with the same ​equipment, procedures, and personnel used in the routine field samples. The relative standard deviation calculated from these replicates should be recorded on control charts and action taken when the precision is out of control [7].
MEASUREMENT:
CALCULATIONS:
EVALUATION OF METHOD:
Lab testing with blank filters and generated atmospheres of carbon black was done at 8 to 28 mg/m³ [2,6]. Precision and accuracy data are given on page 0500-1.
REFERENCES:
[1] NIOSH Manual of Analytical Methods, 3rd ed., NMAM 5000, DHHS (NIOSH) Publication No. 84-100 (1984).
[2] Unpublished data from Non-textile Cotton Study, NIOSH/DRDS/EIB.
[3] NIOSH Criteria for a Recommended Standard … Occupational Exposure to Fibrous Glass, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-152, 119–142 (1977).
[4] 1993-1994 Threshold Limit Values and Biological Exposure Indices, Appendix D, ACGIH, Cincinnati, OH (1993).
[5] NIOSH Manual of Analytical Methods, 2nd ed., V. 3, S349, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-157-C (1977).
[6] Documentation of the NIOSH Validation Tests, S262 and S349, U.S. Department of Health, Education, and Welfare, Publ. (NIOSH) 77-185 (1977).
[7] Bowman, J.D., D.L. Bartley, G.M. Breuer, L.J. Doemeny, and D.J. Murdock. Accuracy Criteria Recommended for the Certification of Gravimetric Coal Mine Dust Personal Samplers. NTIS Pub. No. PB 85-222446 (1984).
[8] Breslin, J.A., S.J. Page, and R.A. Jankowski. Precision of Personal Sampling of Respirable Dust in Coal Mines, U.S. Bureau of Mines Report of Investigations #8740 (1983).
METHOD REVISED BY: Jerry Clere and Frank Hearl, P.E., NIOSH/DRDS.