NEC 2017 Art.501.10 Wiring Methods (B) for class 1 division 2 states:
(4) Boxes and Fittings. Boxes and fittings shall not be required to be explosionproof except as required by 501.105(B)(2), 501.115(B)(1) , and 501.150(B)(1).
501.105 Meters, Instruments, and Relays.
501.115 Switches, Circuit Breakers, Motor Controllers, and Fuses.
501.150 Signaling, Alarm, Remote-Control, and Communications Systems.
So if the junction -or pull box-does not contain any of this devices you may use NEMA 4 [or 4x]. If it does, usually you need NEMA 7.However, there are conditions in which you may use still NEMA 4.See NEC art.501.105(B)(2), 501.115(B)(1) , and 501.150(B)(1).