What is incombustible material?

Answer 1

An incombustible gas is one that does not burn or explode.

(Incombustible means something that cannot be burnt.)

Some good examples of incombustible gases are

1. nitrogen (which is fortunate, because 78% of the air is nitrogen, and if nitrogen was combustible, the air would explode!)
2. carbon dioxide
3. argon

Answer 2

Flammable material can be a solid, liquid or gas. Flammable liquid is a liquid that has a flash point of between 21 and 55°C. The U.S. Occupational Health and Safety Administration (OSHA) defines a flammable liquid as "any liquid having a flash point below 100 deg. F. (37.8 deg. C.), except any mixture having components with flash points of 100 deg. F. (37.8 deg. C.) or higher, the total of which make up 99 percent or more of the total volume of the mixture. Flammable liquids shall be known as Class I liquids."

Definition of combustible liquids, which indicates a material that is somewhat harder to ignite compared to flammable liquids. (Flash point above 100 oF).

OSHA divides flammable (and combustible) liquids into several classes

These categories are further subdivided, depending on the liquid's flash point and boiling point. Highly Flammable liquid: A liquid that has a flash point of less than 21°C. Class IA flammable liquids have a flash point below 73 °F and a boiling point below 100 °F. Class IB flammable liquids have a flash point below 73 °F and a boiling point greater than or equal to 100 °F. Class IC flammable liquids have a flash point greater than or equal to 73 °F and below 100 °F. Class II combustible liquids have a flash point greater than or equal to 100 °F and below 140 °F. Class IIIA combustible liquids have a flash point greater than or equal to 140 °F and below 200 °F. Class IIIB combustible liquids have a flash point greater than or equal to 200 °F

The older term, inflammable is identical in meaning to flammable. To avoid confusion, only use the term flammable. Something that is not flammable is called nonflammable.