We report on a laboratory study of the atmospheric corrosion of NaCl-treated zinc in air containing different concentrations of carbon dioxide (<1, 100, 350, 1000, and 40,000 ppm). Each sample was exposed individually to synthetic atmospheres with careful control of CO2 concentration and flow conditions. The relative humidity was 95%. The protective proper-ties of carbonate-containing corrosion products were investigated in 225 ppb SO2. Mass gain and metal loss results are reported. The corrosion products were analyzed quantitatively and qualitatively by a combination of X-ray diffraction, scanning electron microscopy : gravimetry, and quantitative analysis for carbonate. The corrosion of zinc in the presence of NaCl resulted in heavy pitting of the metal. Carbon dioxide slowed down the corrosion rate by a factor of three to six. This is explained by the neutralization of the surface electrolyte resulting in the precipitation of chloride in the form of insoluble Zn-5(OH)(8)Cl-2. H2O. In the presence of NaCl large amounts of hydroxy carbonates formed. There is no indication that hydroxy carbonates are protective in a SO2 environment.