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Module 6: Fire Fighting Foam Principles

module 6 covers firefighting strategies

and foam used tactics for controlling

and fighting fires associated with the

flammable liquid hazards of ethanol

blended fuels next up we have module 6

in which we'll be discussing

firefighting foam principles we would

like you to be able to describe the

manner in which foam applications can be

used to fight fuel fires to list the

ways in which foam applications suppress

fire to predict when to fight fuel fires

and when to simply protect surrounding

areas and to state generally accepted

rule of thumb for the use of foam

applications on ethanol blended fuel

fires as discussed previously we have

seen the production of ethanol is quite

large and likely to continue to increase

as always emergency responders should be

ready for emergencies associated with

flammable liquids ethanol blended fuels

are similar to other flammable liquids

and their hazards the predominant danger

from ethanol emergencies is not from the

incidents involving cars and trucks

running on ethanol blended fuel but

instead from cargo tank trucks and rail

tank cars carrying large amounts of

ethanol manufacturing facilities and

storage facilities responders need to be

prepared for large-scale emergencies and

prepared with the most effective

techniques and extinguishing media this

module will focus on foam basics and

then foam applied specifically to

ethanol related emergencies the

technical definition of what is foam is

found in NFPA 11

phone concentrate is the concentrated

product of which we're going to make

phone alcohol resistant foam concentrate

is a concentrate used for fighting fires

on water-soluble materials so when their

chemical that you're dealing with the

product that you're dealing with is a

polar solvent that mixes with water the

responder has to use foam that's

compatible with that or alcohol

resistant a triple F ethanol will

continue to burn at five parts water to

one part ethanol or five to one ratio or

five hundred percent dilution many

extinguishing agents are effective on

flammable liquids

however foam is the only agent capable

of suppressing vapors and providing

visible proof of security reasons to use

foam include a foam blanket on an

unindicted co-conspirator by protecting

the hazard until it can be secured or

removed

finally foam can provide protection from

flammable liquids for fire and rescue

personnel during emergency operations

how foam works

foam can control and extinguish

flammable liquid fires in a number of

ways foam can exclude oxygen from the

fuel vapors and thus prevent a flammable

mixture cool the fuel surface with the

water content of the phone prevent the

release of flammable vapors from the

fuel surface and in some environmental

forms emulsify the fuel phone

tetrahedron phones used today are

primarily of the mechanical

tightening this means that before being

used

they must be proportioned mixed with

water and aerated mixed with air four

elements are necessary to produce a

quality foam blanket these elements

include foam concentrate water air and

aeration all of these elements must be

combined properly to produce a quality

foam blanket if any of these elements

are missing or are not properly

proportioned the result is a poor

quality foam or no foam at all

ethanol when it's burning is a Class B

fire Foam is effective on Class B fires

foam will extinguish a Class B fire by

suppressing the vapors and cooling the

product at the same time there are two

different types of Class B products

simple hydrocarbons oil gasoline diesel

fuel and then polar solvents anything

that includes ethanol or ethanol blended

fuels foam terminology before discussing

the types of foam and the foam making

process it is important to understand

the following terms foam concentrate is

the liquid substance purchased from a

manufacturer in a container pail drum or

tote foam solution is the mixture

obtained when foam concentrate is

proportioned mixed with water prior to

the addition of air finished foam is

obtained by adding air to phone solution

through either entrainment or mechanical

agitation types of foam several foam

types have been developed over the years

each with particular qualities protein

foam one of the earliest foams is

produced by the Hydra

Ellis's of protein material such as

animal hoof and porn stabilizers and

inhibitors are added to prevent

corrosion resistant EECOM position and

control viscosity fluoro protein phones

are formed by the addition to protein

foam of special fluoro chemical

surfactants that reduce the surface

tension of the protein based concentrate

and allow more fluid movement aqueous

film forming foam a drop left replaces

protein based foams with synthetic

foaming agents added to floor oak

chemical surfactants designed for rapid

knock down a triple FS sacrifice heat

resistance and long-term stability film

forming flora protein foam or triple FP

is a protein based foam with the more

advanced fluoro chemical surfactants of

a triple F triple fps combined the

burnback resistance of fluoro protein

foam with the knockdown power of a

triple F alcohol resistant AR phone is a

combination of synthetic stabilizers

foaming agents fluoro chemicals and

synthetic polymers designed for use on

polar solvents the chemical makeup of

these foams prevents the polar solvents

from destroying them today's more modern

AR phones can be used on both polar

solvents and hydrocarbons foam will

remove heat at a faster rate than it is

released separate the fuel from the

oxidizing agent dilute the vapor phase

concentration of the fuel and/or

oxidizing agent below that necessary for

combustion

and terminate the chemical chain

reaction sequence a triple left types of

foam lowers the surface tension will

rapidly spread across the surface and

has a high burnback resistance and a

quick knockdown however when we apply a

triple F to polar solvents the polar

solvent will tend to destroy that fine

film blanket and so in order to deal

with that manufacturers have come out

with alcohol resistant a triple F which

will resist the product from actually

eating the film blanket so why you use

alcohol resistant foam alcohol resistant

foam is the only agent capable of

suppressing vapors on a polar solvent

the foam blanket on an unacknowledged

spill can prevent the production of

vapors and the suppression of those

vapors prevents a fire from igniting or

reigniting alcohol resistant foam

provides protection from flammable

liquids for fire and rescue personnel

during emergency operations this chart

shows you the different types of foam

and how they judge their effectiveness

effectiveness is judged on how quickly

it knocks down the fire how resistant it

is to the heat of that fire

the tolerance it has to the fuel or the

product that is spilt or on fire its

ability to suppress and maintain

suppression of vapors and then finally

its tolerance to alcohol alcohol

resistant foams are the only types of

foam that can give us protection in all

five of these areas in order to produce

foam you have to have appliances you

have to have a method of proportioning

the foam concentrate into the water foam

concentrate if we're using alcohol

resistant a triple F

that alcohol resistant foam can actually

be used in different concentrations

based on the fact that we're dealing

with either a pure hydrocarbon or a

potential polar solvent so in the

different concentrations we will need a

proportion or capable of adjusting those

concentrations so when we're talking

about three six percent foam we can use

it in the three percent mode for a

typical hydrocarbon but we have to bump

it up to the six percent mode when we're

dealing with polar solvents foam

proportioning systems include adductors

which can either be inline or already

pre plumbed into a vehicle some phone

proportioning systems can also have a

bypass type of eductor and this means

you can switch from applying foam in

concentrate to going back to flowing

just water but remember if you begin to

apply foam I'm sorry if you begin to

apply water to your foam blanket you

will deteriorate that foam blanket so

you have to be very very careful when

you're using these types of adductors in

order to appropriately apply the foam we

need a nozzle and the nozzle needs to be

of the aeration type that will add air

into the system so that it can be

applied appropriately some foam nozzle

systems include the adductor right at

the nozzle this image shows a fire

hydrant with a foam nozzle attached to

it air aspirating nozzles air aspirating

nozzles are phone generating nozzles

that mix air and atmospheric pressure

with foam solution see figure six point

six in the participant guide these

nozzles produce an expansion ratio of

between eight to one and ten to one and

produce a good quality low expansion

foam

non-air aspirating nozzles fog nozzles

are an example of non air aspirating

nozzles see figure 6.7 in the

participant guide non air aspirating

nozzles produce an expansion ratio of

between three to one and five to one

this expansion ratio is not as good as

that of air aspirating nozzles but these

nozzles often add some versatility which

can be beneficial in various fire attack

situations versatility includes the

ability to switch from a foam solution

to water in order to protect personnel

and provide area cooling air aspirating

nozzles do not offer this advantage a

disadvantage of aspirating and non air

aspirating nozzles is that you must have

additional equipment in order to

generate foam in addition the gallonage

setting on the nozzle must match the set

flow for the eductor

it is important to understand the

benefits of both types of nozzles in

order to select the most appropriate one

large-scale foam appliances so here you

can see a picture of a trailer this

trailer specifically has a thousand

gallon per minute foam application

nozzle on it with this instead of

dealing with five-gallon buckets or

pails of foam we're actually dealing

with totes of foam so a toda foam can be

close to 400 gallons of foam many

departments many facilities are going to

have access to a foam trailer very

large-scale foam application nozzles so

now we're looking at something capable

of four thousand gallons per minute

you're going to need a system like this

if you have a large storage tank on fire

proper application of foam is critical

the key to foam application is to apply

the foam as

gently as possible to minimize agitation

of the fuel and the creation of

additional vapors the most important

thing to remember is never plunge the

foam directly into the fuel the

bounce-off method is effective if there

is an object in or behind the spill area

the foam stream can be directed at the

object which will break the force of the

stream allowing the foam to gently flow

onto the fuel surface the Bank in method

when no obstacles exist to bounce the

foam off firefighters should attempt to

roll the foam onto the fire by hitting

the ground in front of the fire the foam

will pile up and roll into the spill

area this technique is particularly

effective with non air aspirating fog

nozzles the mechanical agitation of the

foam hitting the ground will help to

aerate the phone the rain down method an

alternative application technique is to

rain down the product the nozzle is

elevated and the foam is allowed to fall

over the spill as gently as possible

remember never plunge a stream of foam

directly into the fuel some of the foams

mentioned in the previous sections have

been around for over 50 years and have

proven to be very effective on

hydrocarbon fuels

however these phones were not developed

for application on ethanol blended fuels

and are simply ineffective this is

because the alcohol or ethanol content

of the blended fuel literally attacks

the foam solution absorbing the foam

solution into the ethanol blended fuel

foam that is designed to be alcohol

resistant forms a non perm

membrane between the foam blanket and

the alcohol type fuel it is crucial that

these AR phones are used in combating

ethanol blended fuel fires including e

10 this is an important point

additionally to be effective these foams

must be applied gently to the surface of

the alcohol or ethanol blended fuels

otherwise the foam is absorbed into the

fuel and will not resurface to form an

encapsulating blanket extensive testing

done at the Ansel Fire Technology Center

indicated that even at low level blends

of ethanol with gasoline as low as e 10

there is a major effect on foam

performance the testing also indicated

that with high level blends of ethanol

with gasoline even AR foams required

careful application methodology and

techniques to control fires alcohol

resistant foams AR type foams must be

applied to ethanol fires using type to

gentle application techniques for

responding emergency services this will

mean directing the foam stream onto a

vertical surface and allowing it to run

down onto the fuel direct application to

the fuel surface will likely be

ineffective unless the fuel depth is

fairly shallow less than a quarter of an

inch type 3 applications using fix and

hand line nozzle application is prone to

failure in ethanol blended fuels of any

substantial depth the only time is as

effective is when deflected off of

surfaces such as tank walls to create a

gentle style application it has also

been found that even with indirect

application off surfaces it may require

substantial increases in flow rate to

accomplish extinguishment therefore in

situations where a our foam cannot be

applied indirectly by deflection of the

foam off tank walls or other surfaces

where there is no built-in application

device to provide gentle application the

best option might be to protect

surrounding exposures film application

rates the information that we're going

to cover in the next few slides comes

right out of NFPA 11 which is our

standard on applying foam a triple

f-type phones require approximately one

gallon per minute of thrown solution

flow for every 10 square foot of burning

surfaces of a hydrocarbon tight fuel

ethanol blended fuels require

approximately double that flow or two

gallons per minute per 10 square feet of

an AR type of phone solution as with all

types of foam mixing percentages is

dependent upon the type and the design

of the foam concentrate

what NFPA is telling you is that for

every 10 square foot of a flammable

liquid fire that is involving a typical

hydrocarbon you need to be able to apply

one gallon per minute of the foam

solution to that area in order to put it

out in a polar solvent such as ethanol

NFPA recommends the firefighters double

back concentration or two gallons per

minute per 10 square foot of fire area

departments that are subject to

incidents involving the various blends

of fuels found on highway incidents or

at storage facilities should strongly

consider converting to a our foam

concentrates or develop a means of

having a cache of AR foam

readily available when purchasing foam

ensure that it is ul certified in order

to remain

client with NFPA standards significant

amounts of AR foam may be required if

your emergency response plan involves

relying on mutual aid and mutual aid

assets be sure to confirm what type of

aid will be provided and what

firefighting resources are available the

mixing of different brands of foam can

potentially hinder the desired outcome

and efficiency in which to be performed

it is imperative that departments verify

the compatibility of phones with their

mutual aid providers also be sure to

train emergency responders to use these

assets many departments will utilize the

local airport to come out with a crash

truck to provide foam for an incident

make sure that airport either is usual

is using ara triple F or is capable of

dealing with polar solvents many of them

won't be keep in mind that alcohol

resistant foams are effective on both

alcohol and the hydrocarbon fires AR

foams have a special polymer that forms

a protective membrane between the fuel

and the foam as it contacts the polar

fuel making fire extinguish 'men

possible AR phones also make the foam

more stable and heat tolerant resulting

in better burn back protection or

resistance when compared to conventional

phones it's a matter of fact some of the

a our phones have quicker knockdown

abilities and longer foam retention

times than some of the traditional

protein based hydrocarbon phones it is

recommended that a thermal imaging

camera be used to more accurately

determine if a fire is completely

extinguished

especially during sunlight hours also

note foam tanks and totes cannot be

shaken and remixed easily and can

stratify to avoid this it is

recommended that a maintenance program

be in place to reallocate the phone

periodically if the department has

specific hazard that only involved non

alcohol or non ethanol blended fuels

they may want to consider non AR foam

for that specific hazard

however for transportation incidents

they should have a our foam readily

available if you're not taking your foam

concentrate for a ride every now and

then it won't stay good it will

coagulate inside its containers proper

scene evaluation will assist in making

the right choices for a successful in

incident mitigation keep in mind that AR

phones are effective on both alcohol

fires and hydrocarbon fires if upon

arriving on the scene of an emergency if

you're having difficulty identifying the

exact contents of a tanker then you

always want to apply the foam at the

higher rate or as if it was a polar

solvent if you're applying it as a polar

solvent and it ends up being strictly a

hydrocarbon it will not hurt it'll still

be advantageous to you but if you

applied at the lesser rate and it does

end up being a polar solvent you will

not get the desired the desired results

from the phone application rates

recommended for ethanol spill fires of a

shallow depth follow NFPA 11 increasing

the foam application rate over the

minimal recommendation will generally

reduce the time required for

extinguishment NFPA recommended

application rate for film forming types

of foam equals a tenth of a gallon per

minute per square foot or one gallon per

10 square foot for a period of time of

15 minutes in an ethanol or a polar

solvent fire they recommend increasing

that 2.2 gallons per minute per square

foot or 2 gallons per minute

for 10 square foot of fire to determine

the amount of foam concentrate required

you must find out the type of fuel and

the area of involvement the square

footage multiplied by the application

rate will give you the recommended

gallons per minute the whole formula

will give the concentrate total this

includes the time duration for the

attack and percentage rate for the

concentrate to be used as a note double

the amount of foam concentrate on hand

prior to initiating fire attack this

will cover the fire and maintain the

foam blanket following the knockdown

time duration depends upon the nature of

the incident typical times are 60

minutes for tanks and 20 minutes for

ground spills examples of application

rates for hydrocarbons an area of 2,000

square feet of regular gasoline is

burning you have Universal + 3 6% foam

available for securing the flame at

point 1 0 gallons per minute per square

foot times 2,000 square foot that equals

200 gallon per minute of foam solution

required at 3/100 times 200 gallons per

minute that would equal 6 gallons of 3%

concentrate required per minute 6

gallons times 15 minutes equals 90

gallons of 3% a triple F concentrate

required to control extinguish and

initially secure a 2,000 square foot

hydrocarbon fire application rate

calculations tell you more than just how

much foam do I need they also tell you

what hardware is required for a given

size fire

nfpa also shows a number of application

rates based on what we are dealing with

if it's a simple hydrocarbon tank

depending upon its size the flow rates

and the concentration changes the length

of time in a large storage tank they are

anticipating that those flow rate rates

must be maintained for sometimes up to a

full hour in order to fully extinguish

the fire in the TEC incident foam needs

rule of thumb is to double the amount of

foam concentrate on hand prior to

initial fire attack ar a triple F foam

turned out to be the best choice for

incidents involving those types of fuel

because a are a triple F foam works well

on gasoline fires it is the recommended

choice for all fuel fires involving

either gasoline or ethanol blended fuels

if it is unclear the chemical nature of

the burning fuel ar a triple F is the

preferred choice from a response

standpoint refer to the foam

manufacturer for the recommended

application rate whenever you're dealing

with a railcar that's on fire involving

ethanol or any flammable liquid remember

you need to cool the metal of that

railcar before attempting to extinguish

the fire with foam