Flash Point, Ignition & Autoignition Temperature

These three stages are important terms to understand
how a fuel will behave under various conditions.

Autoignition Temperature of a substance is the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark.

Flammable Liquids
Flash points < 100°F. Class 1 liquids.
1. Class IA liquids - flash points below 73°F and boiling points below 100ºF.
2. Class IB liquids - flash points below 73°F and boiling points at or above 100°F.
3. Class IC liquids - flash points at or above 73°F and below 100°F.

Combustible Liquids
Defined as liquids having closed cup flash points at or above 100°F. Class II or Class III liquids.
1. Class II liquids - flash points at or above 100°F and below 140°F.
2. Class IIIA liquids - flash points at or above 140°F and below 200°F.
3. Class IIIB liquids - flash points at or above 200°F.

NOTE:
The header of these pages just says "Flammable Liquids" but the training also refers to combustible liquids