Page:NIOSH Manual of Analytical Methods - 5700.pdf/1

 FORMALDEHYDE ON DUST (TEXTILE OR WOOD) H2C=O

MW: 30.03

METHOD: 5700, Issue 1

CAS: 50-00-0 EVALUATION:

OSHA : 0.75 ppm; 2 ppm STEL NIOSH: 0.016 ppm; C 0.1 ppm; carcinogen ACGIH: C 0.3 ppm; suspected human carcinogen (1 ppm = 1.23 mg/m 3 @ NTP)

5700

RTECS: 36172

FULL

Issue 1: 15 August 1994

PROPERTIES:

gas; BP -19.5 °C; vapor density 1.067 (air = 1); explosive range 7 to 73 % in air

SYNONYMS: methanal; formalin (aqueous 30 to 60% w/v formaldehyde), methylene oxide

SAMPLING SAMPLER:

Institute of Occupational Medicine inhalable dust sampler or equivalent containing a 25-mm PVC filter, 5 µm pore size

MEASUREMENT TECHNIQUE:

HPLC, UV DETECTION

ANALYTE:

2,4-dinitrophenylhydrazone derivative of formaldehyde

EXTRACTION:

10 mL distilled water @ 37 °C, 4 h; 1 mL to 3 mL 2,4-dinitrophenylhydrazine/acetonitrile (1.3 mg/mL DNP/ACN)

FLOW RATE: 2.0 L/min VOL-MIN: -MAX:

240 L @ 0.002 mg/m 3 1050 L

SHIPMENT:

Place cassette with filter in 30-mL screw-cap low density polyethylene (LDPE) bottle; keep upright. Ship cold.

SAMPLE STABILITY:

21 days (matrix dependent) (cold storage advised)

BLANKS:

2 to 10 field blanks per set

INJECTION VOLUME:

15 µL

MOBILE PHASE:

34% acetonitrile/66% methanol/water (1:1, v/v), 1.0 mL/min

COLUMN:

Radial Compression Module C 18 column, 5-µm particle size, 10 cm x 8-mm ID (with a C 18 guard column) or equivalent

DETECTOR:

UV @ 365 nm

CALIBRATION:

Standard solutions of formaldehyde in 1.3 mg/mL DNPH/ACN

ACCURACY RANGE STUDIED:

0.007 to 0.16 mg/m 3 [1] (1050-L sample)

BIAS:

- 4%

ˆ ): 0.093 [1] OVERALL PRECISION (S rT ACCURACY:

± 22%

RANGE: 0.40 to 4000 µg per sample [1] ESTIMATED LOD: 0.08 µg per sample [1] PRECISION (Sr): 0.078 @ 7 to 174 µg per sample [1]

APPLICABILITY: The working range is 0.0004 to 3.8 mg/m 3 for a 1050-L air sample. This method has been used for the determination of formaldehyde in both textile dusts and wood dusts.[1] Caution should be exercised in the way that data collected with this method are interpreted. These results should be reported separately from vapor-phase formaldehyde exposure dat a until sufficient data has been collected to allow appropriate epidemiological interpretation of formaldehyde-containing partic ulate exposures.

INTERFERENCES: None identified.

OTHER METHODS: In the absence of phenol or other substances known to interfere with the chromotropic acid analysis of formaldehyde, the analysis procedure described in NIOSH method #3500 [2] can also be used with this extraction technique (See Appendix). The analysis procedure used in this method has also been used for the determination of formaldehyde in automo bile exhaust [3]. An alternate analysis [4] may be used in conjunction with this method to determine the amount of "released" formaldehyde from the collected particulate material. NMAM 5700 determines both "released" formaldehyde and formaldehyde equivalents (e.g., small oligomeric pieces of formaldehyde-containing resin) present in the hydrolysis solutions. The us e of these two analytical approaches may differentiate between the two forms of formaldehyde present in the sample by the differenc e in results.

NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94