CARBON BLACK: METHOD 5100, Issue 1, dated 30 April 2015 - Page 3 of 4
CALIBRATION AND QUALITY CONTROL: 10. Zero the microbalance before all weighings. Use the same microbalance for weighing filter capsules before and after sample collection. Calibrate the balance with National Institute of Standards and Technology Class S-1.1 or ASTM Class 1 weights. 11. Process laboratory blanks, spiked QC samples and field blanks at a minimum frequency of 1 per 20 field samples. Internal capsules used for QC samples should come from the same lot. Spiked QC samples, loaded with 0.25 to 4 mg of material per internal capsule, should be prepared using weight-stable material such as Arizona Road Dust [10]. MEASUREMENT: 12. Weigh each capsule, including field blanks. Record the post-sampling weight, W2 (mg). Record anything remarkable about a capsule (e.g., overloading, leakage, wet, torn, etc.). CALCULATIONS: 13. Calculate the concentration, C (mg/m3), of carbon black in the air volume sampled, V (L):
C=
(W2 -W1 ) - (B2 - B1 ) V
103 , mg/m3
where: W1 = tare weight of capsule before sampling (mg) W2 = post-sampling weight of sample-containing capsule (mg) B1 = mean tare weight of blank capsules (mg) B2 = mean post-sampling weight of blank capsules (mg) EVALUATION OF METHOD: Lab testing was carried out using blank internal capsules and with capsules spiked with 0.1 – 4 mg of NIST SRM 1648 (Urban Particulate Matter) and Arizona Road Dust (Air Cleaner Test Dust) [5]. Precision and accuracy data are given on page 5100-1. Weight stability over 28 days was verified for both blanks and spiked capsules [5]. Independent laboratory testing on blanks and field samples have verified longterm weight stability as well as sampling and analysis uncertainty estimates [5]. REFERENCES: [1] CFR. 29 CFR Part 1910.1000. Code of Federal Regulations. Washington, DC: U.S. Government Printing Office, Office of the Federal Register. [2] NIOSH [2005]. NIOSH pocket guide to chemical hazards. Barsan ME, ed. Cincinnati OH: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. DHHS (NIOSH) Publication no. 2005-149. [3] ACGIH [2013]. TLVs and BEIs based on the documentation of the Threshold Limit Values for chemical substances and physical agents and Biological Exposure Indices. Cincinnati, Ohio: American Conference of Governmental Industrial Hygienists. [www.acgih.org]. [Date accessed: February, 2015.] [4] Institut fur Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung [2014]. GESTIS-Database on hazardous substances. (German Social Accident Insurance). Sankt Augustin, Germany: IFA. http://www.dguv.de/ifa/Gefahrstoffdatenbanken/GESTIS-Stoffdatenbank/index-2.jsp [Date accessed: February, 2015.]
NIOSH Manual of Analytical Methods (NMAM), Fifth Edition
