(U//FOUO) DHS/Office of Intelligence and Analysis (I&A) and the Los Angeles Joint Regional Intelligence Center (JRIC) assess that an intentional release of hydrogen sulfide gas most likely would be by a person using it to commit suicide, thus not exposing large numbers of people. The gas is, however, highly toxic and easy to produce from commonly available materials—properties that could make it attractive for use in a terrorist attack. DHS/I&A and JRIC have no information that terrorists are planning an attack in the United States using hydrogen sulfide gas.