Factory, storage, high-hazard, utility (F / S / H / U)

One-line orientation

Groups F, S, H, and U cover production, storage, high-hazard materials, and utility or miscellaneous buildings. For F and S, combustibility separates the moderate-hazard and low-hazard subgroups.

Key points

• F — Factory and Industrial (manufacturing/processing):
  • F-1 (moderate hazard): the default — factory uses not classified as F-2: combustible materials that stop short of Group H (woodworking, furniture, bakeries, clothing).
  • F-2 (low hazard): fabrication/assembly of non-combustible materials posing no significant fire hazard.
• S — Storage (storage as a use in its own right):
  • S-1 (moderate hazard): goods that are combustible but not highly flammable (warehouses).
  • S-2 (low hazard): storage of non-combustible goods.
• H — High-Hazard: manufacturing, processing, generation, or storage of materials that constitute a physical or health hazard. Subgroups H-1…H-5 are assigned by the nature of the hazard:
  • H-1: detonation.
  • H-2: deflagration.
  • H-3: physical hazard.
  • H-4: health hazard.
  • H-5: HPM (hazardous production materials).
• U — Utility and Miscellaneous: buildings that don’t fit other categories and serve limited purposes — barns, carports, sheds, towers.

Confusions / comparison

Group	Lower-hazard subgroup	Higher-hazard subgroup	Split is about
F Factory	F-2 — non-combustible assembly	F-1 — combustible (moderate, short of H)	Combustibility of materials
S Storage	S-2 — non-combustible goods	S-1 — combustible goods	Combustibility of goods
H High-Hazard	—	H-1…H-5 by hazard type	Physical/health hazard beyond F/S
U Utility	—	—	Auxiliary / miscellaneous catch-all

Related

→ Occupancy groups overview (this module): the ten-group map · Construction types (this module): combustibility also drives construction type · B / E / M (this module): the other commercial groups.