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Respirator packs are equipment used by the UNSC. Respirators are worn by UNSC personnel when an atmosphere is not present, and prevent asphyxiation by providing an auxiliary supply of oxygen for the wearer. Every crewman on a Naval vessel is outfitted with a respirator pack. When conducting extravehicular activity in space, a more protective vacuum suit is utilized by UNSC personnel.
The crew of the UNSC Commonwealth were ordered to don respirator packs when Captain Wallace vented atmosphere in the ship to cut off a fire caused by plasma. This was suggested by Doctor Halsey to Captain Wallace, who readily agreed.
During a rebel attack on the UNSC Infinity, Spartan Yeong-hao Holst handed respirators to Commander Thomas Lasky and Jun-A266 after Ilsa Zane vented the oxygen in the ship's S-Deck. The Insurrectionists then proceeded to search the area while wearing the equipment.
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