The major erruption of Volcan de Fuego caused an enhancement of 1.6¿109 kg of SO4- in the stratosphere 6 months after the eruption. Measurable changes in nitric acid vapor and particulate chloride were not observed. Subsequent data suggests that HCl was not injected into the stratosphere. The first simultaneous measurements of halogen and sulfur content of gases and particles in explosive eruption plumes is reported. The average percents of elements in particles were sulfur, 2.5¿2.1; chlorine, 18¿12; and fluorine, 38¿29. The average molecular ratio of HCl/SO2 and HCl/HF were 0.41¿0.26 and 14¿12 in the Guatemalan eruption plumes.