Estimates have been made of the annual emissions of HCl, HF, and SO2 to the troposphere and stratosphere from volcanic eruptions. The estimated annual emission rates to the troposphere are 7.5¿105, 3.8¿104, and 7.5¿106 metric tons, respectively, and those to the stratosphere are 2.8¿104, 1.4¿103, and 2.8¿105, respectively. The results demonstrate that anthropogenic chlorofluorocarbons have the potential to play a much greater role in stratospheric chemistry than the halides from volcanic eruptions do except possibly for short periods following very intense volcanic activity.