Characterization of Graphite Composite Material Particulates from United States Air Force Aircraft Maintenance Operations

Due to the benefits of their material properties, advanced composite materials (ACM) are increasingly being used as structural components on aircraft, especially within the United States Air Force. As a result, the potential exists for occupational exposures to structural maintenance employees while repairing and fabricating aircraft components. Two field studies were conducted for this thesis in order to characterize ACM aerosol size distribution, determine the feasibility of utilizing direct reading instruments (DRIs) in the field, and ensure workers are protected with adequate controls. In order to characterize exposure, traditional integrated air sampling and DRIs were positioned together near an ACM panel being fabricated. Gravimetric analyses and fiber counts were conducted on the integrated samples, whereas particle counts and size distributions were analyzed using the DRIs (optical and condensation particle counters). The second field study involved utilizing the DRIs during a C-17 crash and recovery operation, which confirmed they can be helpful for base-level bioenvironmental engineers (BEEs) for recommending personal protective equipment for the clean-up crew. The results of this research suggest that the combination of an OPC and a CPC enable the creation of one particle size distribution that can be used for ensuring adequacy of engineering controls.