NFPA 520: Standard on Subterranean Spaces covers the unique fire and life safety considerations that exist in subterranean spaces, including means of egress issues such as orientation and excessive travel distances, poor ventilation, communication difficulties, and nontraditional behavior of fire.
The Standard allows the following occupancies within new and existing subterranean space buildings: public assembly, business, educational, detention and correctional, health care, board and care, residential, industrial, mercantile, and storage uses.
Requirements include the latest criteria for:
Changes in the 2016 edition of NFPA 520 include updates to referenced documents.
NFPA 520 is an essential resource for installers, contractors, designers, engineers, facility managers, first responders, and anyone involved with fire and life safety or emergency response in these special environments. It regulates all developed subterranean spaces except tourist caverns, wine storage caverns, gas and oil storage reservoirs, hazardous waste repositories, utility installations such as pump stations, working mines, transportation and pedestrian tunnels, aboveground buildings with belowground stories, and cut and cover underground structures specifically addressed in the building code.