Hexavalent Chromium Dissociation from Overspray Particles Into Fluid for Three Aircraft Primers

The Department of Defense and industry use chromate-containing primer paints extensively to inhibit corrosion on metal assets. Chromate, a primer pigment, provides excellent corrosion inhibition, but contains hexavalent chromium (Cr6+), a human carcinogen. There is no reliable epidemiological evidence of increased lung cancer incidence among painters potentially exposed to primer overspray particles. Using ioaerosol impingers, overspray particles from three different primers (solvent-borne epoxy, water-borne epoxy, and solvent-borne polyurethane) were collected into water to test the hypothesis that the paint matrix influences Cr6+ release into water. This collection method is intended to simulate Cr6+ release from paint particles into lung fluid. Collected particles were allowed to reside in the water for 1 and 24 hours after which the particles were separated from the water by centrifugation.