Building HVAC ducting and air handler requires remediation services to remove all foreign debris and contaminates, to include: Arsenic, Barium, Cadmium, Chromium, Lead, Selenium, Silver, and Silica.Am... Building HVAC ducting and air handler requires remediation services to remove all foreign debris and contaminates, to include: Arsenic, Barium, Cadmium, Chromium, Lead, Selenium, Silver, and Silica.Amendment: Extended response date and uploaded RFI with pictures.