View all text of Subjgrp 176 [§ 57.8520 - § 57.8535]
§ 57.8531 - Construction and maintenance of ventilation doors.
Ventilation doors shall be—
(a) Substantially constructed;
(b) Covered with fire-retardant material, if constructed of wood;
(c) Maintained in good condition;
(d) Self-closing, if manually operated; and
(e) Equipped with audible or visual warning devices, if mechanically operated.