Dissolution of Chromium from Inhalable Primer Paint Particles into a Simulated Lung Fluid

The use of chromate as a corrosion inhibitor in primer paint is an essential component for the protection of aluminum-skinned aircraft and the primary source of hexavalent chromium (Cr (VI)) exposure to USAF aircraft painters. The objective of this research was to quantify the dissolution of chromate from freshly sprayed paint particles into a simulated lung fluid (SLF). Two primer paints were sprayed with a paint spray gun to generate overspray particles for collection into impingers filled with SLF. Particles were allowed to soak in SLF for 24 and 48 hours and then the particles were removed by centrifugation. The remaining Cr (VI) dissolved in the SLF was then compared to the initial Cr (VI) concentration with particles. The results indicate that the dissolution of Cr (VI) into SLF is hindered by the paint. Also, the results indicate that the amount of Cr (VI) dissolved into SLF from the paint particles is not significantly different between the two paints tested or between the 24- and 48-hour resident times. This study suggests that Cr (VI) in paint particles is less bioavailable than Cr (VI) in other particles such as dust or mist.