Retiring rooms shall be ventilated by a window or skylight opening directly to the outside air, except that, where no window or skylight opening is available, the room shall have artificial ventilation or be constructed so that the walls allow at least two feet of space between the ceiling of the retiring room and the top of the walls on at least two sides. The window or skylight shall be constructed so that it may easily be opened, and means shall be provided to keep it open, when so desired by the occupants. If artificial ventilation is used, it shall equal not less than six changes of air per hour when such rooms are in use.
34 Pa. Code § 41.91
This section cited in 34 Pa. Code § 41.204 (relating to retiring rooms for women).