Decontamination chamber

A decontamination chamber (sometimes shortened to decon chamber) was a facility found aboard Earth starships and early Federation starships in which personnel underwent decontamination when returning to the ship after being exposed to potentially hazardous substances or infectious material. The chamber was usually located adjacent to the vessel's shuttle or launch bay. It was secured from the outside to prevent personnel from leaving before the decontamination procedure was complete thereby exposing the rest of the crew. The chief medical officer, or other medical staff, would dispense special decontamination gels or creams to facilitate the removal of the contaminants. 

Notable usage

 * The first time a decontamination chamber was used aboard an starship was in 2151. Subcommander T'Pol and Commander Charles Tucker III applied decon gel to each other after becoming exposed to protocystian spores on Rigel X.
 * In April 2163, the decon chamber aboard the USS Endeavour (NCC-06) was used to hold an atmosphere comfortable for two captured Mutes.