San Francisco Fire Code § 316.7 Barbed or Razor Wire

Barbed or razor wire shall not be on or attached to any fire escape, dry standpipe or other fire extinguishing facility, fence, parapet, roof surface, or any other place on a building or structure where it might hinder or obstruct firefighters in performing their duties. Where barbed or razor wire is on or attached to any location, structure or surface specified in this section, it shall be removed.

Exception: Barbed or razor wire may be installed on fences provided it does not obstruct or hinder egress, rescue operations, or access to hazardous areas, as determined by the fire code official, in the event of fire or other emergency.