Decontam was the large-scale neutralization of harmful organisms, such as parasites and insects, aboard a starship. The process was standard operating procedure for all space vessels prior to being granted permission to land or an in-space rendezvous. Decontam had two phases: a vessel quarantine and the use of gaseous agents harmful to microbes; and irradiation of the vessel's interior. Some planetary health organizations required an inoculation of the crew prior to disembarkation.