Air Framers Module 1 Practice Exam 2026 – The All-in-One Resource to Master Your Certification!

Combustible liquids are defined by how hot you have to heat the liquid before its vapors can ignite. The useful measure is the flash point—the lowest temperature at which enough vapor forms to ignite in air.

In safety classifications, flammable liquids have flash points below 100°F, while combustible liquids have flash points at or above 100°F and below 200°F. So a liquid that has a flash point between 100°F and just under 200°F fits the combustible category.

The other options don’t fit because: a flash point below 0°F is well below the standard threshold for this classification; a flash point above 300°F is outside the 100–200°F range used to define combustible liquids; and vapor pressure is not the criterion used to label liquids as flammable or combustible.