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Development of NIOSH Method 5042: total particulates and benzene soluble fraction (asphalt fume).
Olsen-L; Belinky-B; Eller-P; Glaser-R; Lunsford-R; Neumeister-C; Shulman-S
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 1998 May; :57
During asphalt fume exposure assessment surveys, the results obtained using NMAM 5023 (coal tar pitch volatiles) often exceeded the results obtained using NMAM 0500 (particulates not otherwise regulated, total). After reviewing the methods, NMAM 5023 was withdrawn and the development of a new method using a single sampler for both the total particulates and the benzene soluble fraction was initiated. The resulting method (NMAM 5042) uses a tared, 37-mm, 2-um pore size, polytetrafluoroethylene membrane filter for sampling. After sampling, the tared filter is reweighed, and the difference is the amount of total particulate collected. The tared filter is then extracted with 3 mL of benzene, and the extract filtered. Next, -.5 mL of the filtered extract is dried in a tared weighing cup in a vacuum oven. Once the benzene evaporates, the tared weighing cup is reweighed and the difference is the benzene soluble fraction of the total particulates. The pooled relative standard deviation was 4.8% for loadings equal to or greater than 0.10 mg per sample for total particulates. For the benzene soluble fraction, the pooled relative fraction was 6.1 % for loadings equal to or greater than 0.20 mg per sample. Since no independent method for determining total particulates is available, no estimate of the bias was made. However, if the total particulate loading is equal to or greater than 0.10 mg per filter, there is at least 95% probability that the determination will be within 250/0 of the true value 95% of the time if the upper 97.5% confidence limit on the bias is less than 11.5%. For benzene solubles, for which the bias is constant when more than 0.20 mg is on the filter, there is at least 95% probability that the determination will be within 25% of the true value 95% of the time if the loading is equal to or greater than 0.20 mg per filter. The limit of detection (LOD) and the limit of quantitation (LOQ) for total particulates were 0.04 and 0.13 mg per filter, respectively. The LOD and LOQ for the benzene soluble fraction were 0.04 and 0.13 mg per filter, respectively. An independent chemist evaluated the method with pyrene (1.08, 0.392, 0.216 mg per filter). A mean total particulate recovery of 106% (SD=6.1%) was obtained, and the mean benzene soluble fraction recovery was 109% (SD=11.0%).
Analytical-Method; Analytical-methods; Sampling-methods; Sampling; Filters; Filter-membranes; Filter-materials; Asphalt-fumes; Coal-tar-pitch; Volatiles; Particulate-sampling-methods; Particulates; Samplers; Benzenes; Pyrenes
71-43-2; 9002-84-0; 129-00-0
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia
Page last reviewed: July 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division