Most high-end UPSes have a relay where you can run an active-high or active-low emergency power off (EPO) signal. The EPO can either be a button that is pressed manually by the staff, automatically via fire suppression system, or both/either.
Schneider-APC white paper (PDF)
* https://download.schneider-electric.com/files?p_File_Name=AS...
The EPO can also cut-off the HVAC so oxygen is no longer fed into the area, and smoke isn't (re-)circulated.
In the US, this is probably covered in NFPA 75, "Standard for the Fire Protection of Information Technology Equipment":
* https://www.nfpa.org/codes-and-standards/all-codes-and-stand...