Flammable and Combustible Liquid Definitions

 

Flammable Liquids

Defined as liquids having closed cup flash points below 100°F (37°C) and vapor pressures not exceeding 40 psi (276 kPa) (2.76 bar) at 100°F (37°C). Flammable liquids are referred to as Class 1 liquids.

1.   Class IA liquids – flash points below 73°F (22.8°C) and boiling points below 100°F (37.8°C).

2.   Class IB liquids – flash points below 73°F (22.8°C) and boiling points at or above 100°F (37.8°C).

3.   Class IC liquids – flash points at or above 73°F (22.8°C) and below 100°F (37.8°C).

 

Combustible Liquids

Defined as liquids having closed cup flash points at or above 100°F (37°C). Combustible liquids are referred to as Class II or Class III liquids.

1.   Class II liquids – flash points at or above 100°F (37.8°C) and below 140°F (60°C).

2.   Class IIIA liquids – flash points at or above 140°F (60°C) and below 200°F (93.4°C). c.

3.   Class IIIB liquids – flash points at or above 200°F (93.4°C).