Section 108.173 - Class I, Division 2 locationsThe following are Class I, Division 2 locations:
(a) An enclosed space that has any open portion of the mud circulating system from the final degassing discharge to the mud suction connection at the mud pit.(b) A location in the weather that is- (1) Within the boundaries of the drilling derrick up to a height of 3 m (10 ft.) above the drill floor;(2) Below the drill floor and within a radius of 3 m (10 ft.) of a possible source of gas release; or(3) Within 1.5 m (5 ft.) of the boundaries of any ventilation outlet, access, or other opening to a Class I, Division 2 space.(c) A location that is-(1) Within 1.5 m (5 ft.) of a semi-enclosed Class I, Division 1 location indicated in § 108.171(b) ; or(2) Within 1.5 m (5 ft.) of a Class I, Division 1 space indicated in § 108.171(e) .(d) A semi-enclosed area that is below and contiguous with the drill floor to the boundaries of the derrick or to the extent of any enclosure which is liable to trap gasses.(e) A semi-enclosed derrick to the extent of its enclosure above the drill floor or to a height of 3 m (10 ft.) above the drill floor, whichever is greater.(f) Except as provided in § 108.175 an enclosed space that has an opening into a Class I, Division 2 location.