Enligt the100.wikia.com installerade de syrgasskrubber i S04E13. Den relevanta delen från den wiki (betoning är min):
"Then, Murphy, Emori, Harper, Monty, Raven, Bellamy, and Echo get onto the Ark, but Raven is low on oxygen. Murphy and Emori decide to share theirs along with everyone else. Meanwhile, Monty instructs Bellamy to connect the oxygen scrubber to the conduits on the Ark."