Chromate decontamination in incineration furnaces, Warsaw

Before the overhaul of two incineration furnaces at a plant in Warsaw, the furnace interiors and the furnace doors were tested for chromium(VI). The quick tests on the door and on the fly ash reacted positive; the purple color of the samples indicates chromate. Chromate-containing dust lay on all surfaces, on door frames, inspection windows and the tops of the doors, and on the scaffolding inside the furnace.

Decontamination was carried out by aerosol spraying with KavarClean® redox solution. All surfaces were wetted from top to bottom and from back to front so that the solution gets its reaction time and the dust is bound. The bound dust was then swept up with low dust generation, collected in sealable bags and wetted again when carried out. Dust pockets at the doors were collected separately.

The crew worked in category 5/6 protective suits with taped seams, two pairs of nitrile gloves and full-face masks with P3 filters. Chromium(VI) compounds are water-soluble and absorbed through the skin; half masks are not sufficient. Exit was by spraying down the suits before leaving the furnace and again outside on an absorbent mat.