What is the foam that firefighters use?

What is the foam that firefighters use?

aqueous film-forming foam

Why do firefighters use foam?

Firefighting foam is a foam used for fire suppression. Its role is to cool the fire and to coat the fuel, preventing its contact with oxygen, resulting in suppression of the combustion.

Why do firefighters use water instead of foam?

Class A foams are used to lessen the surface tension of water, which improves the wetting and saturation of water used to fight Class A fires, which are fueled by ordinary combustibles.

When was AFFF foam first used?

The Navy received a patent on its invention in 1966 and by the mid 1960’s the 3M Company was manufacturing AFFF for the military. By the late 1960’s, the U.S. Navy required all of its vessels to carry AFFF. In the 1970’s the Department of Defense began using AFFF to fight fuel fires at all military installations.

Does Afff contain Pfas?

All AFFF products contain PFAS. This applies to foams used in the past and those being sold today. Foam currently in stock or new foam that is labeled as AFFF or AR-AFFF, contains perfluoroalkyl or polyfluoroalkyl substances, or both, as active ingredients (DOD 2018; Darwin 2004).

Does high expansion foam contain Pfas?

High-Expansion Foam is used in fighting Class-A, Class-B, and LNG fires both indoors and outdoors. Fluoroprotein Foam is produced using PFAS. The PFAS chemicals are not PFOA or PFOS. However, in earlier fluoroprotein foams, PFOA and PFOS may have been present in low levels.

What is the difference between low expansion foam and high expansion foam?

LOW EXPANSION FOAM: Foam aerated to an expansion ratio of between 2 to 1 and 20 to 1. HIGH EXPANSION FOAM: Expansion ratio above 200 to 1. DILUTION RATE, MIXING RATE, OR PROPORTIONING RATE (correct amount of foam concentrate to be mixed with water): The amount is normally shown on the pail or drum of concentrate.

Is high expansion foam toxic?

Because of this high expansion ratio and their light weight, high expansion foams are typically used in confined indoor spaces such as air craft hangars, ships, machinery spaces and mine shafts. High expansion foams do not contain this surfactant and are overall low in toxicity.

What is the ratio of high expansion foam?

High-expansion foams are those that expand in ratios of over 100:1. Most systems produce expansion ratios of from 400:1 to 1000:1.

What is high expansion foam used for?

High Expansion foam is suitable for use in combating fires in buildings, process areas, warehouses, and aircraft hangar systems. High expansion foam systems can be used for protection of LNG storage areas by quickly blanketing the flammable liquid surface and helping to control vapor release.

What does a foam proportioner do?

National Foam Proportioners utilize the water flowing through them to produce a venturi effect that induces foam concentrate into the water stream. Line Proportioners are venturi devices that introduce foam concentrate into a flowing stream of water at a controlled proportioning rate.

What is the most common type of foam eductor?

In-Line Foam Eductors

What is foam not effective on?

1.1 specifically states, “Foam is not suitable for three-dimensional flowing liquid fuel fires or for gas fires.” F-500 Encapsulator Agent has proven itself to be very effective on three-dimensional fires around the world.