FORMALDEHYDE ON DUST/FIBERS: METHOD 5700, Issue 1, dated 15 August 1994 - Page 4 of 5
EVALUATION OF METHOD: This method was evaluated over the range of 7 to 174 µg/sample at 24 °C and pressure of 761 mm Hg [1] using the chromotropic analysis procedure. Overall measurement precision, SˆrT, was 0.093 including a 5% pump error factor. Similar precision was observed with the 2,4-dinitrophenylhydrazine analysis procedure. Sample stability during storage was evaluated at 7 µg formaldehyde/2 mg of wood dust treated with a urea/formaldehyde resin. Samples showed 101% recovery after 21 days of storage at ambient conditions compared to one-day old samples. However, studies with a different matrix (ureaformaldehyde treated wood fibers) indicated that samples may be unstable when stored at room temperature. Comparison of results from 2,4-DNP analyses with those from acetylacetone analyses [4] indicated that there was a significant difference between the two methods. The acetylacetone analyses used much milder conditions and appears to be reacting only with released formaldehyde, whereas the 2,4-DNP analysis required the addition of perchloric acid and may be breaking up oligomeric pieces of the partially hydrolyzed resin in the sample. By analyzing samples with the two methods, a further characterization of the sample matrix and potential exposure may be obtained. In matrices where materials that can form complexes with formaldehyde are present, such as sulfites, the acetylacetone analysis may be biased low, since it is unable to break up these complexes [8]. Two comparisons of the I.O.M. samplers with closed-face cassette samplers were conducted in field situations [1]. The I.O.M. samplers, on average, collected more dust/fibers measured gravimetrically than the closed-face cassette samplers in both studies. Formaldehyde levels in the dust/fibers on a µg/mg basis measured with the extraction procedure used in this method were comparable for both the I.O.M. and closed-face cassette samplers. On the average, the I.O.M. sampler tended to collect more dust that the closed-face cassette sampler. REFERENCES: [1]
[2] [3]
[4] [5] [6]
[7] [8]
Kennedy, E.R., Y.T. Gagnon, A.W. Teass and T. Seitz, "Development and evaluation of a sampling and analytical method for the determination of formaldehyde content of dust," Appl. Occ. Environ. Hyg., 7(4), 231-240 (1992). Formaldehyde. In NIOSH Manual of Analytical Methods, Method 3500. P. Eller, Ed., DHHS (NIOSH) Publication No. 84-100, NIOSH, Cincinnati, OH (1984). Lipari, F., and S. Swarin, "Determination of formaldehyde and other aldehydes in automobile exhaust with an improved 2,4-dinitrophenylhydrazine method", J. Chromatogr. , 247, (1982) 297306. Elia, V.J. and R.A. Messmer, "Evaluation of method for estimating formaldehyde released from resin-containing paper and wood product dusts," Am. Ind. Hyg. Assoc. J., 53, 632 (1992). Particle Size Selective Sampling in the Workplace. American Conference of Governmental Hygienists, Cincinnati, OH (1985). NIOSH/OSHA Occupational Health Guidelines for Occupational Hazards, U. S. Department of Health and Human Services, Publ. (NIOSH) 81-123 (1981), available as GPO Stock #017-03300337-8 from Superintendent of Documents, Washington, D. C. 20402. Particulate Not Otherwise Regulated, Total. In NIOSH Manual of Analytical Methods, Method 0500. P. Eller, Ed., DHHS (NIOSH) Publication No. 84-100, NIOSH, Cincinnati, OH (1984). Nash, T., "The colorimetric estimation of formaldehyde by means of the Hantzsch reaction," Biochem. J., 55, 416 (1953).
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NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
