Carbon fibers are small, highly conductive, and lightweight. When released as emissions from production, manufacturing, processing & disposal sources, they are readily airborne & can be dispersed over wide areas. Because of their high electrical conductivity, carbon fibers settling out of the atmosphere onto electronic or electrical components can cause malfunctions and damage. This research program was initiated to develop techniques to identify and measure carbon fiber concentrations emitted from manufacturing, processing, fabricating, and incinerating sources. The overall objective of the research was to develop a measurement method to meet possible emission source regulations.