What are flammable and combustible materials?

Materials that are flammable or combustible can burn or ignite causing fire or other heat giving reactions.

The National Fire Protection Agency (NFPA) places flammable and combustible liquids in the following classes:


Flash Point*

Boiling Point

Class IA

< 73°F (22.8°C)

< 100°F (37.8°C)

Class IB

< 73°F (22.8°C)

>100°F (37.8°C)

Class IC

>73°F (22.8°C

 <100°F (37.8°C)


Flash Point*

Boiling Point

Class II

>100°F (37.8°C)

140°F (60°C)

Class IIA

>140°F (60°C)

200°F (93°C)

Class IIIB

>200°F (93°C)


*Flash Point is defined as the minimum temperature at which a liquid gives off vapor in sufficient concentration to form an ignitable mixture with air near the surface of the liquid.

Class A     Class B     Class C     Class D
High           Moderate   Low           Minimal  

How do I handle flammable and combustible materials?

When handling these materials you should always:

  • Eliminate ignition sources such as open flames, hot surfaces, sparks from welding or cutting, operation of electrical equipment, and static electricity
  • Assure appropriate fire extinguishers and/or sprinkler systems are in the area
  • Ensure there is proper bonding and grounding when it is required, such as when transferring or dispensing a flammable liquid from a large container or drum. Assure bonding and grounding is checked periodically
  • Do not heat flammable liquids with an open flame. Steam baths, salt and sand baths, oil and wax baths, heating mantles and hot air or nitrogen baths are preferable.
  • Minimize the production of vapors and the associated risk of ignition by flashback. Vapors from flammable liquids are denser than air and tend to sink to the floor level where they can spread over a large area.
  • No storage of flammable chemicals in container sizes greater than 1 gallon will be permitted in labs unless: a) The flammable chemicals are stored in a flammable storage cabinet or b) The flammable chemicals are stored in an approved flammable safety can.

What do I do if the material spills?

  • Turn off all possible sources of ignition
  • Alert those in the immediate area
  • Vacate area and notify proper authority

Page last modified March 2, 2015