Solution:

Class A fires are ordinary combustibles: wood, paper, plastic, those types of things we expect normally to be combustible and burn.

Class B fires are now flammable and combustible liquids and flammable gases, and so some suppression systems work to extinguish Class B type fires. We see a lot of Class B hazards in manufacturing and industrial, not normal types of spaces where we’d see Class A fires.

Class C fires can occur in a lot of different places, usually around electrical equipment. A Class C fire is a fire that’s electrically enhanced, or sometimes I say an electrically commutated fire. There’s an arc, some sort of short or arc due to a malfunction in some electrical equipment, but that’s a sustained arc. That arc is an ignition source, so any combustible materials around it have that sustained ignition source, and therefore Class C fires are typically harder to extinguish.

Class D fires are something that we don’t talk about a lot. They’re not that common. Class D fires are fires that occur in combustible metals