46 CFR § 111.103-7 - Ventilation stop stations.
Each ventilation stop station must:
(a) Be protected by an enclosure with a glass-paneled door on the front;
(b) Be marked, “In Case of Fire Break Glass and Operate Switch to Stop Ventilation;”
(c) Have the “stop” position of the switch clearly identified;
(d) Have a nameplate that identifies the system controlled; and
(e) Be arranged so that damage to the switch or cable automatically stops the equipment controlled.