Silicon carbide whiskers: characterization and aerodynamic behaviors.
Cheng-S; Powell-QH; Smith-SM; Johnson-NF
Am Ind Hyg Assoc J 1995 Oct; 56(10):970-978
An analysis was undertaken of the physical and aerodynamic properties of silicon-carbide (409212) (SiC) whiskers to assess their potential as an occupational health hazard. Industrial grade SiC fibers (density 3.25+/-0.006 grams per cubic meter, surface area 1.4+/-0.1 square meters per gram) were dispersed into a stainless steel chamber at a flow rate of 22.5 liters per minute (l/min) using a small scale power disperser. Aerosol samples were collected through a mixed cellulose-acetate/cellulose-nitrate filter (25 millimeters, 0.3 micrometer pore, flow rate 2l/min) and a cascade impactor (flow rate 12l/min) to determine aerosol concentration. Electron microscopic analysis was performed to measure fiber dimension and morphology. Particle sizes were determined after samples were separated via a Lovelace aerosol particle separator. SiC particle sizes ranged from 0.65 to 1.9 micrometers. The majority of SiC whiskers were straight and rod shaped, although single bends (12%) and double bends (2.7%) were also observed. A log normal distribution of SiC whisker length and width was noted. Fiber axis orientation was shown to influence fiber aerosol aerodynamic size. Aerodynamic size distribution estimates from data collected using the cascade impactor were smaller than those from data collected with the aerosol centrifuge.
NIOSH-Publication; NIOSH-Grant; Respirators; Silicon-compounds; Fibrous-dusts; Dust-analysis; Particle-aerodynamics; Aerosol-sampling; Occupational-hazards
Aerosol Science Lovelace Biomed & Environ Res PO Box 5890 Albuquerque, NM I 87185
Respirator Research; Respirators
American Industrial Hygiene Association Journal
Lovelace Institutes, Albuquerque, New Mexico