NFPA Firefighter I cheat sheet

Fire tetrahedron components are fuel, oxygen, heat, and chemical chain reaction; extinguishment removes at least one component.

Fire classes: A ordinary combustibles; B flammable/combustible liquids and gases; C energized electrical equipment; D combustible metals; K cooking oils and fats.

PASS extinguisher sequence: Pull the pin, Aim at the base, Squeeze the handle, Sweep side to side.

Ground ladder placement: base one foot from the building for every four feet of vertical height, about a 75-degree angle.

For roof access, extend a ground ladder three to five rungs above the roof edge.

One gallon of water converted to steam expands to roughly 1,700 gallons and absorbs substantial heat.

Primary search is rapid and systematic, covering the immediate fire area and common exit paths while staying below the thermal layer.

Vertical ventilation opens the highest point first and provides a lower inlet so hot gases and smoke escape upward.

Backdraft indicators include a confined fire, heavy smoke, little visible flame, and inward smoke movement; oxygen introduction can cause explosive ignition.

Two-in/two-out rule: at least two firefighters enter an IDLH atmosphere together while two trained and equipped firefighters remain outside ready for rescue.

Incident command establishes a single IC, maintains accountability, and uses formal transfer-of-command briefings.

Needed fire flow (Iowa formula): length times width times number of floors, divided by three, in gallons per minute.

Type I construction is fire-resistive with protected structural members; Type V is wood-frame combustible construction.

Wet-pipe sprinkler systems hold water under pressure and each head opens individually when heated.

Dry-pipe sprinkler systems hold compressed air; when a head opens, air escapes and water enters the piping.

Photoelectric detectors respond to visible smoke from smoldering fires; ionization detectors respond to invisible products from flaming fires.

AFFF is a Class B foam for hydrocarbon fuels; it forms a film that suppresses vapor and excludes oxygen.

Positive pressure ventilation uses a blower at the inlet and an opposite exhaust opening to push smoke and heat out.