FIREFIGHTING FOAMJANUARY, 2015

QuickTrainCrewReview

QuickTrain CrewReview trainings have been developed to serve as brief springboards for crews to discuss emergency response theory and implement hands-on training as it best fits into each crew’s daily schedules and incident response.

WHAT IS FOAM?

An aqueous solution which is lower in density than flammable liquids

Used principally to form a cohesive floating blanket on flammable and

combustible liquids Prevents or extinguishes fire by excluding air and cooling the

fuel Prevents reignition by suppressing formation of flammable

vapors Adheres to surfaces to provide increased exposure protection

from adjacent fires

CONSTITUENTS OF FOAM

AIR

+ + AGITATION

+

Remember foam percentages and proportioning systems.

•Typically for hydrocarbons, foam is proportioned at 3%•For polar solvents, foam is usually proportioned at 6%•Some foams work at much lower concentrations, e.g. 1%.

Proportioning Methods Include•line eductors•self-educting nozzles•pressure systems•pump proportioning systems

TYPES OF FOAM

Protein foam: produced by the hydrolysis of protein material such as animal hoof and horn.

Fluoroprotein foam: formed by the addition to protein foam of special surfactants that reduce the surface tension of allow more fluid movement.

Aqueous Film-Forming Foam (AFFF): synthetic foaming agents added to surfactants

Film-Forming Fluoroprotein Foam (FFFP): protein-based foam with fluorochemical surfactants

Alcohol-Resistant (AR): combination of synthetic stabilizers, foaming agents, fluorochemicals, and synthetic polymers; designed for use on polar solvents

WHEN TO USE FOAM?

To cover horizontal surfaces so water remains in contact with hot surfaces longer and absorbs more heat

To flow over a burning liquid surface and form a blanket sealing volatile combustible vapors ambient air.

To provide visual confirmation that a fuel surface has been covered in situations where a fire has been extinguished or ignition has not occurred.

To pre-treat structures for protection against impending wildland fires or to guard exposures from nearby fires

WHEN IS FOAM INEFFECTIVE?

When fighting class C/D fires Against three-dimensional

Class B fires Against leaking, pressurized

gases

“A three-dimensional class B fire involves Class B materials in motion such as pouring,

running, or dripping flammable liquids, and generally includes vertical as well as one or

more horizontal surfaces.”

Adapted from NFPA 10

APPLICATION TECHNIQUES

Proper application is critical for foam. Apply the foam as gently as possible to minimize agitation of fuel and

creation of additional vapors. The most important thing to remember: never plunge foam stream directly into the

fuel. This will agitate fuel and create additional vapors.

bounce-off bank-in

rain-down

FIREFIGHTING FOAMJANUARY, 2015

QuickTrainCrewReview