Doors must typically swing in the direction of egress travel when serving:

• A High-Hazard occupancy of any occupant load.
• Any occupancy type with an occupant load of 50 or more occupants (consult the code for exceptions).
• Exit enclosure doors except when serving one living unit (NFPA 101 only).

Two measurements must be taken into account with regard to encroachment:

• The door may not extend more than halfway into the required egress width at any point in the door’s swing.
• The door may not extend more than 180 mm into the required egress width when in the fully-open position. Latching hardware on the corridor side of the open door is not taken into account if it is mounted between 865 mm and 1200 mm above the finished floor.

What determines the direction in which a door must swing?

Source: https://idighardware.com/2012/10/door-swing-and-encroachment/