Flammable and Combustible Liquids

Storage Requirements

Not more than ten (10) gallons of combined Class I plus Class II liquids should be outside of an approved flammable storage container. This means that 10 gallons can be out and everything else must be in a flammable storage cabinet or properly functioning safety cans.

A flammable storage cabinet may be minimally vented and only via the provided bung(s). In addition, any venting must be approved by Fire Protection and Special Services. Any flammable cabinet that has been cut into will not be approved and must be removed from service.

Link: Common Class I, Class II, and Class III Liquids


Flammable Liquid Classes (NFPA* 30)

Flammable Liquids
ClassFlash Point (FP)Boiling Point (BP)
IA FP < 73° F (22.8° C) BP < 100° F (37.8° C)
IB FP < 73° F (22.8° C) BP ≥ 100° F (37.8° C)
IC 73° F (22.8° C) ≤ FP < 100° F (37.8° C) NA
  • Class IA flammable liquids have a flash point less than 73° F (22.8° C) and a boiling point less than 100° F (37.8° C).
  • Class IB flammable liquids have a flash point less than 73° F (22.8° C) and a boiling point greater than or equal to100° F (37.8° C).
  • Class IC flammable liquids have a flash point greater than or equal to 73° F (22.8° C) but less than 100° F (37.8° C).

  *NFPA = National Fire Protection Association


Combustible Liquid Classes (NFPA 30)

Combustible Liquids
ClassFlash Point (FP)
II 100° F (37.8° C) ≤ FP < 140° F (60° C)
IIIA 140° F (60° C) ≤ FP < 200° F (93° C)
IIIB 200° F (93° C) ≤ FP
  • Class II combustible liquids have a flash point greater than or equal to 100° F (37.8° C) but less than 140° F (60° C).
  • Class IIIA combustible liquids have a flash point greater than or equal to 140° F (60° C) but less than 200° F (93° C).
  • Class IIIB combustible liquids have a flash point greater than or equal to 200° F (93° C).