Thread: AFFF or FFFP

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    Post AFFF or FFFP

    Which type of foam is your department mainly using, AFFF or FFFP, or maybe something else?

    Alcohol resistant or not?

    Your experience deploying medium expansion foam, AFFF vs. FFFP?

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    This document might help:

    Foam Reading Between The Lines

    What is the best foam? What are the generic types of foam? What are their strengths and weaknesses? Does brand make a difference? Do you need more than one type? Is there really a "do-everything" foam? Can you use a fog nozzle, or do you need a "real" foam nozzle? Don't feel bad if you've ever wondered about any of these questions. You're not alone! This series of articles is written to help find some answers.
    If you read everything that's been written by the manufacturers of foam, and if you study Underwriters Labs (U.L.) and military specifications (Mil Specs), American Petroleum Institute (API) and Federal Aviation Administration (FAA) papers and talk to end users, you'll find a bunch of compromises. As you work your way through this maze of information, you'll find at least eight generic types of what veteran firefighting foam instructor Flynt Josey calls the "foam family". Eleven manufacturers produce 22 variations of the eight foams. The one you choose should be based on head-to-head comparisons in the real world environment in which you operate.
    To understand fully which foam is best for a particular purpose, it's important to review the entire foam family. It can be subdivided into three expansion ratios(the ability of the foam solution to hold air in a useable form): 1) low expansion is up to 20:1; 2) medium expansion is from 20:1 to 200:1; and 3) high expansion, ranging from 200:1 to 1,400:1. The expansion ratio is the amount of finished expanded foam that will be produced using the correct nozzle. One gallon of foam solution will make 1400 gallons of finished foam with the correct nozzle and concentrate. In this article series, we'll break the foam family into two primary branches: One is detergent-based, and the other is protein-based, including fluoroproteins.
    Each branch of the foam family tree has inherent strengths and weaknesses. Detergent foams, which are always synthetic, are the first branch of the family we'll examine. These foams, known as high-expansion (HiEx), Class A (referring to Class A fires), medium expansion and wildland foams are available in 0.1 percent to 3 percent concentrates. One 3/6% AFFF foam can be used on Class A fires at 0.05%, a truely universal agent. HiEx and medium expansion foams are designed in 0.3 percent to 3 percent concentrates. HiEx and medium expansion foams are designed for flooding areas.
    HiEx generally is the last choice for flammable liquid fire suppression when compared to any of the other foam types. However, some manufacturers claim they are effective for flammable liquid fire suppression. In fact, a few are formulated for flammable liquid firefighting. One even has a 2 3/4 percent concentrate, but I've never seen an eductor with a 2 3/4 percent setting.
    One of the newest uses for HiEx foam is formation of a vapor barrier for certain hazardous materials, including flammable liquids, in multi-dimensional situations. One manufacturer points out that HiEx is "...the only foam currently available that is compatible or use on acid or alkaline materials." A secondary use for HiEx foams is in flooding of large-area Class A and B fires. A medium expansion nozzle with Class A foam can help firefighters stretch their water supply during overhaul. HiEx is used in some aircraft hangars for filling and extinguishing in large spaces. The main drawback of HiEx foam is its inability to resist heat. Also, if a wind comes up, your protection may end up in the next county.
    Nozzles used for application of foam include high-, medium- and low-expansion, and fog nozzles. High expansion foams convert one gallon of foam water solution (concentrate and water combined) into 200 to 1,400 gallons of "expanded foam" when using a high expansion foam generator. Medium expansion nozzles produce 20 to 200 gallons of expanded foam. The end result is far more foam output for the dollar when compared to low expansion foam and fog nozzles. One clip on foam tip will produce low and medium expansion foam. The foam blanket can be a few inches thick or many feet high depending upon need.
    Low expansion foam produces 6 to 20 gallons of expanded foam with low expansion foam nozzles. Firefighting fog nozzles make three gallons of expanded foam per gallon of solution. Some of the better automatic fog nozzles can produce up to eight gallons of foam per gallon of solution.
    We would all do well to remember that foam aeration is directly related to safety. Burn-back and vapor suppression depends on the amount of air you add; up to a point, the more air you add, the more protection generally offered. The combination of low- and medium-expansion nozzles will provide the greatest flexibility (low-expansion for knockdown and reach, and medium-expansion for vapor suppression and burying the problem).
    The main advantage of medium expansion nozzles is that a larger volume of foam is gently applied on the fire. Foams 1,4,5,6 and 8 can be safely and effectively used with low and medium expansion nozzles, and they should be.
    Wildland foams are used in wildland firefighting through handlines, dropped from air tankers and sprayed from helicopters using monitor nozzles. This produces a shave- cream-type foam that can be sprayed on vegetation to hold water long term, allowing fire crews to build a line around a fire. It can be sprayed onto houses and other threatened exposures and will resist direct flame contact. Reportedly, it expands the firefighting capability of contract helicopters conducting overhaul on wildland fires by four to five times. Some wildland apparatus uses medium and high expansion foam generators to lay foam lines as fire breaks.
    The implications for this foam in structural firefighting are just now being explored by some of America's most progressive departments. Wildland foams allow water tank supplies to go further. They improve knockdown and allow a secure overhaul. The fire should stay down long enough between applications to possibly allow you to run for water. Wildland foams allow your water to stay in place instead of running off.
    This type of foam may someday be used on all structural apparatus as a way to reduce water damage and increase fire attack capability, especially in rural areas. This type of foam can be injected into the fire stream using a pump. Compressed air can be injected, producing compressed air foam streams (CAFS) which do not need a nozzle, just a gate valve, to control the line for the ultimate in foam production. Also, wildland foam can be picked up by a venturi eductor with a foam nozzle used to add air. Many departments dump the foam concentrate into the water tank and apply it with a fog nozzle with a clip-on foam tip. That can cause problems with the plumbing. A simple injection system is the best bet.
    The second branch of the foam family tree is protein. Proteins were introduced in mid-1930s. They are available in 3 percent and 6 percent concentrates. Protein foams were the first to offer good heat resistance. Hot fuels or hot metal surfaces that destroyed synthetic detergent foams would no longer be a problem. Burn-back resistance is significantly better with protein foam than any detergent foam.
    Protein foams will not tolerate fuel mixing any better than detergents, so gentle application is important. Detergent foams offer a quicker knockdown than protein agents. This is because protein foams tend to be stiffer, requiring them to be pushed not sprayed. In other words, they don't flow well.
    Protein-based foams can offer a significant advantage over detergent-based foams, however. Under some conditions, detergent foams make certain fuels easier to ignite. For example, a diesel fuel spill might require two to three minutes of direct flame contact to ignite. However, if you spray a detergent foam over the fuel surface and then hold a flame above the fuel surface, it will ignite in as little as five seconds.
    This phenomenon occurs because the detergent breaks down the petroleum product, separating the heavier contents from the light ends and, effectively, lowering the flash point of the materials remaining on the surface.
    Proteins do not have this effect. Protein foams do require the use of an air aspirating foam nozzle. Detergent foams are most effective when used with a foam nozzle but a fog nozzle can achieve a faster knockdown, but at the expense of safety. (The burn-back time is likely to be much shorter.)
    What do the manufacturers of protein foams say about their products? One says, ". . . protein foam is not destroyed by heat. It flows smoothly over the fire's surface to form a protective, cohesive blanket. It acts to extinguish the fire by separating the fire from the fuel, preventing further release of flammable vapors and cooling the area. The foam's water content helps to cool both the fuel and surrounding metal surfaces." Another says protein foam ". . . is a proven, reliable agent for the protection of most hydrocarbon liquid fire risks. Efficient extinction is gained by producing a tough, cohesive, vapor suppressing foam blanket, which has excellent heat stability and burn-back resistance. Of all foam types, well-formulated protein-based foams possess the greatest stability and resistance to hot liquid fuels." Another manufacturer states they have, ". . . good expansion properties and good re-ignition (burn-back) resistance characteristics."
    Protein foam is still the only foam that can meet the demanding U.S. Coast Guard shipboard safety requirements. Detergent foam and protein foams were the only choices for flammable liquid fire protection until the mid-1960s and the introduction of fluoroprotein foams and aqueous film forming foam (AFFF). The choice was speed of knockdown with detergents or a safe secure extinguishment with proteins. If you ask the firefighters who have to enter a spill area whether they want speed or safety, you'll probably get one answer: safety.
    In 1965, the second branch of the foam family was expanded. Available in 3 percent or 6 percent concentrates, fluoroprotein (FP) foam was the result of efforts to make a better protein foam. Fluoroprotein foam has all the good properties of protein foam, but it flows better across the fuel surface and has much faster knockdown. It is the first foam that can shed fuel. It also allows rough application on the fuel surface. It can even be injected under the fuel surface without fuel pickup.
    What do the manufacturers say? One says, ". . . fluoroprotein liquids represent the single most significant improvement in foam technology . . . [Its] improved characteristics include: increased extinguishment ability, increased fluidity, dry chemical compatibility, superior seal-ability and burn-back resistance . . . ." They also report ". . . several advantages over protein foams. Fluoroprotein foams are useful for hydrocarbon vapor suppression and extinguishment of fuel in depth fires . . . ." Another says, "Fluoroprotein foam has become the top choice of the oil and petrochemical industry . . . [It] has the ability to shed hydrocarbons that would cause other types of foam to breakdown."
    Fluoroprotein foam was . . . "specifically developed for use . . . against fires in high-risk situations involving bulk storage of hydrocarbon liquids. They were developed primarily to provide optimum foam properties for controlling and extinguishing aircraft crash fires but also [they are] ideal for general use against hydrocarbon spill fires. In refineries, tank farms and wherever low-flash-point fuels, such as gasoline, are stored in bulk, the danger that long pre-burns may build up hot zones in deep fuel layers is ever present. Under such circumstances standard protein foams, however applied, quickly become contaminated with the fuel, burn themselves and are therefore ineffective. In contrast, fluoroprotein is highly tolerant to fuel contamination and controls and extinguishes such fires, forming a secure and lasting blanket.
    "Fluoroprotein foam compound is ideal for use against aircraft crash fires, where rapid and lasting control is of prime importance in rescue and life-saving operations," reports one manufacturer. Another manufacturer says fluoroprotein foams provide . . . "control on difficult terrain, clinging to hot metal. [It provides] fast extinguishment, [and also is] effective on gasohol [fires]. Recommended for aircraft crash firefighting and rescue. Fluoroprotein foam has generally the optimum combination of properties for refinery, petrochemical and chemical operations."
    Fluoroprotein foam has replaced protein foam in most applications. Still the choice is speed with detergents or safety with fluoroproteins. The main disadvantage of fluoroprotein foams versus detergent foams is that fluoroprotein foam must be used with an air aspirating foam nozzle. Detergents can be used with spray or foam nozzles. The use of a foam nozzle or clip on foam tip greatly improves firefighter safety with all foams with only a slight decrease in the speed of knockdown. You'll almost always spend less money because you'll use less foam concentrate.
    Percentage
    * Foam concentrate: The raw foam liquid in the foam can used to make foam solution.
    * Foam solution: The correct mixture of water and foam concentrate.
    * Finished foam: The correct mixture of foam solution expanded with air using a nozzle.
    *Expansion ratio: The amount of air added by the nozzle 20:1, 200 to 1, etc.
    Foam concentrate percentage is directly related to how much concentrate you need to carry to treat a given amount of water. A 500-gallon water tank would require 30 gallons of 6 percent, 15 gallons of 3 percent, or 5 gallons of 1 percent concentrate. (Note: the larger the percentage, the weaker the concentrate.) A foam educted at two-tenths of 1 percent (0.002) would only require one gallon to treat the tank. The amount of concentrate required is figured by multiplying the water tank capacity by the concentrate percentage. For example, 1,000 gallons x 0.06 percent (6 percent) = 60 gallons. 750 gallons x 0.03 (3 percent) = 22.5 gallons. 2,500 gallons x 0.01 (1 percent) = 25 gallons.
    To figure concentrate needs for eductors or foam systems, simply determine the gpm rate and multiply by the percentage of concentrate. A 95-gpm eductor needs 95 gpm x 0.06 (6 percent) = 5.7 gallons of concentrate per minute. Obviously, this is going to be a problem because it takes more than a minute to run to get and open a foam pail. One percent (1 percent) concentrate would be consumed at less than one gallon per minute. So, a five-gallon pail of 1% would last 6 times longer a pail of 6%.
    The most common "around-the-pump" foam systems and some self-educting foam nozzles have flows to 750 gpm. That means 750 gpm x 0.06, 0.03 or 0.01 = 45, 22.5, or 7.5 gallons of concentrate per minute. NFPA says you need a 50-minute application rate on a tank fire for a whopping requirement of 50 minutes x 45, 22.5 or 7.5 gallons; or 2,250; 1,125; or 375 gallons of concentrate. One industrial master stream requires 720 gallons of concentrate per minute. (That could cost as much as $14,000 per minute.)
    Your choice of concentrate has a direct affect on your ability to pack the needed agent. As a general rule, the engine should carry enough concentrate to treat the entire on-board water supply. If you carry two foam tanks with Class A (structural and wildland) and Class B (flammable liquids) concentrates, the tanks should address the individual concentrate percentages carried.
    On a rig with a 750-gallon water tank, you'd need at least 2.25 gallons 0.3 percent Class A(structure or wildand) foam concentrate, and it would be a good idea to carry enough for five to 10 loads of water if you use it all the time. The Class B (flammable liquids) requirement could be from 7.5 gallons to 45 gallons, depending on the concentrate carried. Some departments that have set up for flammable liquid fires like to carry at least two loads of concentrate for sustained operations. ISO wants to see 15 gallons of Class B on the rig and an additional 10 gallons in the station or on the rig. So at least shoot for a 25-gallon Class B foam tank.
    The rig with 25 gallons of 1 percent Class B solution is going to fight six times more fire than the unit with 25 gallons of 6 percent. If you carry a dual-rated foam concentrate, such as a 3%/6%, 1%/3%/6%, 0.5%/3%/6% or a 1%/3% the tank should be sized for the highest percentage. So you'll end up with two-or three-load capability on the low end, but only one load on the high end of the percentage. Think ahead. Foam tank selection often lasts 30 years.
    AFFF's
    Foam is not magic. It can lull you into some very dangerous situations. Your lack of understanding could cost lives, including yours or your crews'. Using foam agents recklessly can lead to some nasty surprises. This is one subject we can all learn more about.
    The mid-1960s brought to the fire service a new synthetic detergent foam, AQUEOUS FILM FORMING FOAM (AFFF). This is the fourth member of the foam family. AFFF is available in 1 percent, 3 percent and 6 percent concentrates. One manufacturer produces a 15 percent halon/AFFF.
    AFFF reportedly extinguishes fires differently than do protein or fluoroprotein foams. Protein and fluoroprotein foams extinguish by cooling the fuel and hot surfaces, smothering the fire with a cohesive foam blanket, separating the flame from the fuel surface, and suppressing fuel vapors. By contrast, one manufacturer says that three different fire extinguishing mechanisms are employed by AFFF.
    "First, an aqueous film is formed, which works to PREVENT the release of hydrocarbon fuel vapors. Second, the layer of foam effectively excludes oxygen from the fuel surface. Third, the liquid content of the foam provides SOME cooling effect. AFFF demonstrates superior extinguishment and burnback characteristics on NORMAL hydrocarbon fuels."
    None of the manufacturers explain what a NORMAL hydrocarbon fuel is! One manufacturer gives us a clue by saying the U.S. Naval Weapon Center's AFFF testing concludes that "film formation does not occur on certain hydrocarbon fuels." Has anyone bothered to tell the fire service which hydrocarbon fuels they're talking about? Do we have to wait for the foam to tell us? Another says AFFF is INTENDED for use in air aspirating hardware. It may be used in non-air aspirating hardware "...with SOME DECREASE in certain performance characteristics."
    What is "SOME DECREASE" in performance when using a fog nozzle instead of the "INTENDED" foam nozzle? A foam nozzle will provide two to six minutes of burn-back resistance with most AFFF agents. Use a fog nozzle and you'll have only 5 to 7 seconds of burn-back resistance with most nozzles, and as much as 65 seconds with some of the better automatic fog nozzles. The advantage of a fog nozzle is slightly quicker knockdown. The real concern should be firefighter safety!
    Remember, without the foam bubble AFFF cannot accomplish two of the three "extinguishment mechanisms" it relies on. It will not exclude oxygen or provide sustained cooling.
    If you intend to secure vapors, one manufacturer says, "rapid sweeps of a FOAM NOZZLE over the spill will effectively seal it." The foam bubble is the key to AFFF. Another says, "The foam QUICKLY COLLAPSES to produce a water film barrier that effectively covers flammable liquids and HELPS to control vapor release from volatile liquids. The foams are designed to have a high collapse rate that results in a rapid knockdown of the fire and creates a liquid film barrier that quickly spreads over the surface of the flammable liquid. The film barrier can also be effective in CONTROLLING vapor release from volatile liquids. BUT, since even small breaks in the film can negate ANY containment benefits, it is best to maintain a VISIBLE blanket of foam over the liquid surface at all times. Due to the high collapse rate of the foams, problems may be experienced in sealing against hot metal surfaces and in maintaining an effective barrier to vapor release. Long duration spill situations may require more frequent applications of AFFF foam..."
    Another manufacturer recommends Hi-Ex foam for vapor suppression and not relying on AFFF for vapor suppression. Several say, "Unnecessary activity in the spill area should be avoided and repairs to disturbed areas with fresh foam streams should be made as soon as possible."
    Should you trust an invisible barrier two ten-thousandths of an inch thick? Some fire fighters say they won't enter a spill until the foam is knee high! That's good advice. Mobil Oil says, "The foam blanket produced should be of such thickness as to be visible before firefighters rely on the aqueous film being vapor suppressant. The film may be present, but because of invisibility it cannot be relied-upon."
    Speed or Safety?
    The primary advantage of AFFF over Fluoroprotein is a very fast knockdown at low application rates. One producer points out, "Recent comparative tests against AFFF show fluoroprotein foam, when applied at higher rates of application, will extinguish a spill fire IN EQUAL TIME and will provide BETTER burn-back (re-ignition) protection."
    Comparative testing supports this. Three-percent (3 percent) fluoroprotein foam costs 23 percent less than 3 percent AFFF to put out the same fire just as fast, but keep it out at least 75 percent longer! Another supplier points out, "For the small fire situations and spills, film forming foams are most effective in terms of agent efficiency. However, when foam application rates are high, all foams can give acceptable extinction times. For larger fires, burn-back resistance and foam stability becomes increasingly important and the protein based foams, including fluoroprotein, have advantages."
    Several manufacturers produce a high performance grade of AFFF as well as their "everyday" grade. The better grade AFFF helps to overcome the shortcomings of the low-bid stuff. The foams provide an extra margin of performance and safety. AFFF is the only foam in the foam family with multiple grades. When you go to bid it is a good idea to know what grade you need, and if it does makes a difference. Don't just ask for the cheapest AFFF!
    The manufacturers of some AFFFs point out their 6 percent concentrates are faster film formers than their 1 percent or 3 percent versions. A recent FAA status report on current foam fire fighting agents supports this. Recent American Petroleum Institute (API) tests say AFFFs as a whole are "markedly inconsistent" when compared to fluoroprotein and protein foams. The FAA testing points out that 6 percent AFFF's from four major manufacturers will provide 7 percent faster control, 26 percent quicker extinguishment and 14 percent longer burn-back protection than the average 3 percent AFFF. Six percent AFFF will control a fire 3 percent quicker, extinguish 6 percent faster but it's burnback will be 6 percent faster than the average 1 percent AFFF.
    When they compared brand against brand, Underwriters Labs (UL), Mil spec., and other approvals did not seem to make any difference. In fact, only six of 18 foams could produce a marginally acceptable spreading barrier. Depending on which brand and percentage of AFFF selected, they noticed a 9 percent to 70 percent difference in control times, 3 percent to 53 percent difference in extinguishment times, and a 23 percent to 51 percent difference in burn-back resistance. It pays to know what you're buying. Another way to read these differences is how much extra foam (money) you'll use to do the same job of a better concentrate. The AFFF with the most listings may not be worth the most money. Other members of the foam family don't have these wide variations in performance.
    The greatest advantage of AFFF is said to be its ability to spread very rapidly when compared to protein or fluoroprotein foams. Aqueous film formation is dependent on a fuel surface, especially if you intend to use a fog nozzle. If your fires occur on crowned roadways, the shoulder of the road, railroad sidings, dirt, gravel, sand or grass, be aware of the fast draining nature of AFFF. They will be wicked away by grass, absorbed into the ground or will run off, possibly negating your protection.
    This, in conjunction with firefighters breaking the foam blanket while doing their jobs, could result in "ghosted foam." Ghosted foam has visible bubbles that don't provide any protection, or worse yet, the bubbles are saturated with fuel and ready to burn. Nice flat fuel surfaces like we see in a pit fire rarely exist. Most pits and tank fires float the fuel on water. The water absorbs the heat in the fuel-not necessarily something you'll ever find in real life.
    It's interesting to note how the foam manufacturers suggest you test your AFFF for film formation. One recommends pouring cyclohexane or cigarette lighter fluid to give a depth of 1/8" into a glass petri dish. "Place dish on black surface and under a lamp if possible so as to aid in observing the film spread. With a medicine dropper CAREFULLY place three drops of premix on fuel surface at center of dish. With aid of reflected light observe the spreading film. After one minute, pass a lighted probe over the surface of the fuel. BE SURE to have a smothering plate handy IN CASE OF IGNITION!"
    Current standards allow a FLASH across the fuel surface but not an ignition. How would you like to be caught in a real world flash? Some fire service professionals believe the AFFF standards are written to show AFFF's strengths and not its weaknesses.
    Will film formation occur on anything other than cyclohexane or lighter fluid? One way to find out is to substitute gasoline or diesel fuel. Use more than 1/8" of fuel. If the fuel is hot (use an immersion heater) or cold, all of the AFFF may sink to the bottom. Repeat the test by pouring the AFFF on the fuel surface. Notice the word pour. Using an eye-dropper is gentle application, which is rarely possible on the fire ground. Using a drop or two of food coloring in the AFFF premix, it will help you see where the foam ends up.
    Another test you can try is to fill a cake pan with diesel fuel. Hold a propane torch with the air holes taped closed to give a visible flame over the fuel surface. Start a stopwatch to see how long it takes to get the fuel to burn. Normally, it should take two to three minutes. Premix AFFF in a spray bottle. In a second pan full of diesel fuel, spray the fuel surface five times with AFFF. Start your stopwatch. In 5 to 30 seconds, depending on the make of AFFF foam you use, you will have ignition. The detergent base of the AFFF spray is changing the ignition characteristics of the diesel fuel. Think about that the next time you apply AFFF on a spill.
    If you allow the pans to burn for a few minutes and then put them out with AFFF, and immediately hold a torch over the fuel surface, it will instantly re-ignite.
    One final test to demonstrate how quickly your protection drains away is to fill a bottle half-way with premix AFFF and shake it a few times. You'll instantly see the water drain out of the bubbles. It will bring new meaning to the word "drain time."
    Chevron Oil points out that, "Mistakes provide valuable lessons for all fire fighters." Let's look at some. A firefighter operating a circular saw in an effort to free occupants of an aircraft that crashed on a golf course in Southern California may have experienced some of the characteristics we've reviewed about AFFF.
    Photos and live film footage show firefighters to their knees in AFFF but an ignition still occurred. If there were breaks in the visible blanket, in theory those remaining bubbles would be draining their water to form an aqueous film. This apparently didn't occur, possibly because there wasn't a flat unobstructed liquid fuel surface. Possibly the grass golf course they were working on was wicking away the foam, leaving a ghosted foam in its place.
    Or, possibly, as the manufacturer of that foam points out, "With all foams, the foam blanket itself will become saturated with hazardous vapor long before the atmosphere above the blanket has reached the lower explosive limit. This process, in time, renders the foam blanket itself a dangerous source of flammable vapor." At some point all that is needed is an ignition source and all your foam goes up in flames. The sparks from the saw was the ignition source.
    It's important to note that earlier we read the manufacturer's warnings about walking through their AFFFs. Four manufacturers recommend foam production using medium expansion nozzles to secure vapors. Simply putting the fire out is only half the job of a good safe foam! Should foam work in the wind and rain? Another points out that one of fluoroprotein foam's main advantages is "control in adverse weather conditions."
    Chevron Oil said in a company critique of a well publicized tank farm fire, even though AFFF was successful in extinguishing the fire, "for tank fires fluoroprotein seems to be most effective." During that fire, firefighters standing in a gasoline spill using a fog nozzle set on a wide fog pattern discharging AFFF narrowly escaped serious injury. Their AFFF foam stream broke up the existing foam blanket. Chevron Oil says as a general rule, "if you can't see the foam blanket don't trust it. Don't disturb a foam blanket. Always have a way out. Avoid entering a pool of fuel."
    Recent API sponsored research determined that fluoroprotein was superior to any other foam tested, including AFFF, when used to extinguish unleaded gasoline. API says, "AFFF foams were markedly inconsistent. Fire performance was characterized by ease of control and difficulty with final extinguishment." The end result of AFFF was "flicker fires eroded the AFFF foam blanket and flashed around the rim of the tank until the raw fuel became exposed, subsequently leading to sustained burning of the entire tank." Tripling the AFFF concentration did not improve performance.
    In API tests AFFFs did not seal against hot tank shell walls as well as fluoroprotein or even protein foams! Once again, the key is gentle application of AFFF with foam nozzles. If gentle application is unrealistic, then fluoroprotein foam is the obvious choice. Mobil Oil says AFFF may be used on storage tank fires provided "that adequate cooling water is applied to the tank shell." Once again the question is speed or safety.
    Another recent disastrous tank farm fire points out the hot-fuel high-heat limitations of AFFF. A fire in a diked area of 590 by 295 feet was attacked by a crash truck with AFFF. There was almost immediate burn-back. Fluoroprotein foam was laid down behind it to produce an effective foam blanket and final extinguishment. The product burning was crude oil. Crude oil exhibits the burning characteristics of all products that can be refined from it. Why do we keep making excuses for poor foam performance?
    During an aircraft fire in August, 1985, "airport firemen ran out of foam." Using FAA's formula, the aircraft in question required 1,005 gallons of foam water solution to control the fire and 2,010 gallons of foam water solution to extinguish the fire. The airport fire department arrived carrying four to eight times that amount of AFFF. On arrival, airport firefighters were faced with "a burning wing and tail and pools of burning fuel surrounding the aircraft."
    What had occurred during an aborted takeoff was the engine exploded, throwing hot metal through the wing fuel tank. The aircraft just happened to come to a stop in front of the airport fire station. "Firemen quickly extinguished the blaze, but while the evacuation was in progress the fire flared again. Foam was directed onto the blaze and also doused several escaping passengers. The fire went out a second time but quickly flared once more. By then the airport fire crew had run out of AFFF and were using hand-held extinguishers in a bid to save the people still in the burning aircraft."
    They were dealing with a relatively small airliner, but it is the most produced aircraft of all time. They carried 50 percent more AFFF than required to extinguish the largest airliner. The airport fire crews met the aircraft before it came to a halt. Obviously, this was the ultimate response. "Airport firefighters didn't think anyone would have survived if they hadn't been there so soon." All of this occurred in "less than 120 seconds." The end result was 55 dead. If we don't learn from this experience and others and put what we've learned into practice, how can we avoid repeating them in the future?
    What have we learned from these incidents? We have a choice speed or safety. If speed is essential, AFFF and a fog nozzle is the ultimate on some types of fires. One supplier says that in aircraft crash fires, "burn-back resistance is perhaps of secondary importance but should not be ignored, especially for the larger passenger aircraft where rescue of survivors may take some time. The protein-based agents have advantages in this respect, although this will be less evident when spray (fog) nozzles are used since these are not efficient foam makers."
    Once again, we are told by the manufacturers to use a foam with the nozzle it was designed to be used with-an air aspirating foam nozzle. Another states, "A spill fire...or an aircraft accident, generally require the use of aspirating foam discharge devices with AFFF agents. The reason for this is that the safety of life is a primary factor, however, burn-back resistance is also a factor, providing time necessary for rescue from the aircraft."
    Another warns that conventional AFFFs may be used effectively with properly designed water spray nozzles under some conditions, "although a very unstable foam with relatively poor re-ignition resistance is formed from such devices." Do we want to send firefighters into "a very unstable foam blanket with poor re-ignition resistance?" It sounds like the fire service already has, a couple of times!
    According to one large supplier, the U.S. Government (Air Force, Navy, Marines, etc.) use fog nozzles on some crash trucks "based on a conscious decision that the fire will be completely extinguished because of the quantities of AFFF that the vehicles can bring to bear on an aircraft crash." The U.S. government's foam requirement formula is the same as the FAA's. So maybe this "conscious decision" is not one we should emulate.
    Two manufacturers wrote their words two to ten years before the 55 people died in the aircraft fire mentioned earlier. If a safe, secure, survivable knockdown is essential, fluoroprotein in conjunction with an air aspirating foam nozzle is the ultimate!
    Tests conducted by A.A. Briggs and J.S. Webb of the Fire Research Station in the United Kingdom concluded, "petrol can reduce effectiveness of some foams." Their testing with "well known brands" showed that "some AFFFs show vulnerability to contamination by petrol, notably where conditions lead to SOME by no means extreme turbulence of application...i.e., they may fail to extinguish petrol fires." AFFF, due to it's detergent base, picks up fuel. As we saw earlier, this is not the case for fluoroprotein foams. In fact, in the petrol tests by Briggs and Webb, AFFF controlled the fires quickly but would not put them out. Fluroprotein would put them out in all cases.
    In other cases, control with AFFF was the same or similar to fluoroprotein, but the fluoroprotein would still extinguish the fire much quicker. When compared side by side on trace lead gasoline, it was 41 percent to 88 percent faster than AFFF. Is the key speed of extinguishment AND burn-back protection?
    Now that we've taken a look at the three most common generic foam types it's important to ask what makes a good safe foam? One supplier provides a simple summary of the advantages of each type of foam: "PROTEIN; cost-effective, many successful extinguishments, burn-back resistance, water-bearing, seals against hot metal, long-term vapor suppression, non-corrosive, USCG approved, Mil Spec., FLUROPROTEIN; oil resistant, water-bearing, burn-back resistance, seal-ability, long-term vapor suppression, non-corrosive, resists plunging, self-healing, dry chemical compatible, AFFF; quick knockdown, self-healing, aqueous film, Mil Spec., non-aspirating equipment, dry chemical compatible.
    A good safe foam should have five characteristics: "1) Flows freely over the flammable surface. 2) Forms a continuous vapor-tight blanket. 3) Resists heat. 4) Resists flammable fuel pickup. 5) Is sufficiently water-bearing to cool and extinguish."
    Now that we know what makes a good safe foam, let's grade the three most common foam types. Which types of foam flow freely over the flammable surface? Fluoroprotein and AFFF. Which foams form a continuous vapor-tight blanket? Fluoroprotein and Protein. Which foams resist heat? Fluroprotein and Protein. Which foams resist fuel pickup? Fluoroprotein. Which foams are sufficiently water-bearing to cool (both fuel and metal) and extinguish? Fluoroprotein and Protein. The overall performance characteristics grade for each foam is Protein 60 percent, AFFF 20 percent and Fluoroprotein 100 percent. Until the early 1980s there still were only two choices: speed of detergents or the security of proteins.
    Triple FPs
    The newest foam type is Film-Forming Fluroprotein Foam (FFFP) introduced in
    the early 1980s. The fifth in the foam family, it is available in 3 percent and 6
    percent concentrates. FFFP is a protein- or detergent-based foam that has an
    Underwriters Laboratory (UL) listing as both an Aqueous Film-Forming Foam
    (AFFF) and a fluroprotein. The end result it has the best of the AFFF and
    fluroprotein properties.

    Protein-based FFFPs don't have the weaknesses of detergent-based AFFFs.
    One manufacturer says FFFPs "Provide the knockdown of AFFFs and the
    sealability of fluroprotein. It is ideal for use at airports, for spill protection and
    municipal fire departments, according to a paper presented to the American
    Petroleum Institute by Mobil Corporation's research and development division.
    Tests concluded that FFFP foam has substantially faster knockdown than
    fluroprotein foam, achieving knockdown almost as quickly as AFFF. FFFP foam
    has substantially better vapor suppression than AFFF, with blanket stability
    almost as good as fluroprotein foam. The preformance of FFFP on gasohol is
    similar to AFFF performance.

    FFFP used with a medium-expansion nozzle against low-level controlled-burning
    liquid natural gas lasted for 15 minutes, whereas detergent foams lasted three
    minutes. FFFPs are the only protein-based foams that can be used with
    standard fire department fog nozzles; with AFFFs, safety is compromised. One
    supplier says Spray (fog nozzle) application from portable equipment is not
    generally recommended as the prime method of attack for major fires where the
    security of a stable foam cover is essential. We have to decide if we want speed
    or safety.

    Making the Decision
    Testing at the Fire Research Station demonstrated that FFFP would control
    unleaded gasoline just as fast as AFFF; however, AFFF was unable to put the
    fire out. FFFP controlled and extinguished fires almost twice as fast as
    fluroprotein foam. Leaded gasoline showed similar results: AFFF controlled the
    fires in 29 seconds; fluroprotein in 33 seconds; and FFFP in 34 seconds.
    Extinguishment times were as follows: AFFF 231 seconds, fluroprotein 164
    seconds and FFFP 75 seconds. If speed of complete extinguishment is
    important, FFFP is three times faster, and therefore safer, than AFFF. An FFFP
    can be subsurface injected at 1 percent even though it is a 3 percent
    concentrate; that's the lowest UL application rate. It also is listed at the lowest
    rate for hydrocarbon spill fires, as is AFFF.

    If absolute speed is a priority, AFFFs are faster at control, but not necessarily at
    extinguishment. Where absolute safety is concerned, fluroprotein is the best
    choice. If you need both, FFFP is the only choice short of carrying two foams.


    Understanding the Technology
    With all the talk about the new film technology and so many departments using
    FFFP and AFFF to the exclusion of all other foam types, it is important that we
    understand the concept. Top-side application on petroleum tank fires and crash
    fire rescue applications are different than spill fires where the firefighter is on the
    line. Flammable liquid fires should be engineered out, not fought out. However,
    with an engine company, you don't have time to engineer the fire out; you must
    fight the fire out or wait.

    AFFFs and FFFPs do not rely on the foam bubble for knockdown like all other
    foams. That is why there is an emphasis on fog nozzles. The sooner the foam
    bubbles drain into an aqueous solution, the faster the fuel surface will be
    covered. If there isn't a dike or tank wall to keep the foam on top of the fuel, the
    foam will run off or sink. Instant reapplication and foam blanket repair is
    essential. That is where the foam bubble should come in.

    If you insist on subscribing to the concept of non-aspirated foam, then
    immediately after knockdown, cover the spill using a medium-expansion nozzle.
    In some cases, the application of aqueous foams through fog nozzles may not
    secure the fire long enough to lay a safe blanket before a reflash occurs.
    Aviation fuels flash in excess of 12 feet per second. Firefighter survival should
    not be dependent on an invisible barrier.

    If speed is that important, the fog-nozzle aqueous foam lobby has missed the
    point. Speed without safety is reckless and irresponsible. If you truly subscribe
    to speed above all else, buy the whole concept. The original idea was to use
    aqueous foams with simultaneous application of a dry chemical (twin agent)
    through the same turret or handline. Testing has shown the best dry chemical
    can achieve knockdown as much as 20 times faster than AFFF. There is no
    question that twin agents provide the absolute fastest knockdown possible. They
    are significantly faster than either agent alone.

    The simultaneous application of a dry chemical gives us a three-dimensional fire
    attack capability that current foams do not have. The fire service's failure to
    employ the three-dimensional agents in conjunction with foam in aircraft spill
    fires and those in bulk storage tanks have already resulted in scores of close
    calls, deaths and injuries.

    Some professionals suggest a two-foam, same-nozzle approach: FFFP or AFFF
    fog-nozzle knockdown followed by immediate application of fluroprotein foam
    through a foam nozzle, which is more effective than reliance on film formation
    alone. Those against it say it isn't convenient and fire trucks don't come
    equipped for its use. Now almost every new engine is delivered with two foam
    tanks one for Class A and another for Class B agents. It is not all that difficult to
    have two Class B tanks. Others want the best of all worlds: They recommend
    twin-agent attack with fog-nozzle AFFF or FFFP and immediately burying the
    problem with a medium-expansion nozzle.


    FFFP would allow one foam to do both without modifying the apparatus or the inconvenience of stocking two foams. One way to improve both concepts is to use a foam nozzle instead of the fog nozzle with any agent. Not only will your burnback be much better, your foam will go further and stick to surfaces that fog-nozzle aqueous foams would run off. If we really intend to provide the utmost in protection, a twin-agent knockdown followed by a deep, safe foam blanket made by a medium-expansion nozzle is what we owe the public. Unfortunately, this essential tool is lacking at airports and the typical engine company. In the next part of this series we look at polar foams.
    Polar Foams
    Foam types one through five work only on hydrocarbon fuels such as naptha (unblended gasoline), diesel oils, etc. They are effective on polar hydrocarbon blends, including super unleaded gasoline and gasohol up to 10 percent to 16 percent of the blend. Polar solvents above 10 percent of the blend will break down standard firefighting foams one through five, however. Polar solvents and polar solvent blends are soluble in water, or hydrophilic. They dissolve water in foam bubbles. To see this or teach it, premix aqueous film-forming polar foam (AFFF) in a bottle. Shake it up and pour the bubbles over a dish of rubbing alcohol The bubbles will disappear like they're being eaten. If your risks include alcohol, methylethylketone (MEK), acetone, thinners and other flammable liquids, you need to choose from foams six, seven or eight. Future Environmental Protection Agency (EPA) clean-air standards will one day increase polar additives, making todays' foams potentially obsolete on unleaded gasoline fires or spills. Never forget, in a world of increased hazardous materials awareness, that eight of 10 hazmat calls concern flammable liquids.
    Polar solvent foams build two kinds of barriers to keep the absorption of water in foam bubbles to a minimum acceptance level. One type of barrier is like a plastic wrap over the fuel surface. If a firefighter walks through the foam, though, the barrier can attach itself to the firefighter's boots and be destroyed or pulled from under the foam blanket. The second type is a nonplastic film that will not pull away.
    Polar solvents require deep foam blankets for vapor suppression. Any break in the foam blanket could cause the fire to reignite. Polar solvents are not as forgiving as hydrocarbons.
    Foam Nozzles
    Probably the last thing anyone should attempt is to put a polar-fuel fire out with a fog nozzle. Although some manufacturers say it works, even if you were able to put the fire out, you might not have vapor control. Reignition would be certain. It's similar to putting out natural gas fires-the invisible vapors are more dangerous than the fire itself.
    A high-quality foam nozzle is essential for success. Some manufacturers support this by saying, "Non-aspirating [fog] nozzles should not be used." Gentle application of foam on polar solvents is more important than it is on hydrocarbons. Another manufactuer says, "In the case of polar solvents, gentle application using an air-aspirating foam nozzle to slowly build up a foam blanket is recommended." Medium expansion nozzles with polar foams provide the gentlest, longest-term method of application.
    Pros and Cons
    Foam six is a fluroprotein polar foam (FPP) and was introduced in the mid 1960s. It does everything a fluroprotein on hydrocarbon fires, but will also work on polar solvents. The foam comes in a 3%/6% percent concentrate, requiring 3 percent for everyday hydrocarbon fires and 6 percent for polar-solvent fires. FPP foams produce a barrier that will not pull away. FPP is the most fluid of the polar foam concentrates. It can be used with almost any eductor or proportioner.
    Foam seven is an aqueous film-forming polar foam (AFFFP), that was introduced in the mid-1970s. It does everything AFFF does, but will also work on polar solvents. AFFFPs are available in 6%/6%, 3%/6%, 3%/5%, 3%/3% percent and 1%/3% concentrates. The first percentage rating is for hydrocarbons. The second is for polar solvents. So if you have a fire involving naptha, or straight-run gasoline, set your proportioner to the lowest setting on the foam pail. For polar fuels, use the highest percentage. Some older foams still in use have 4%/6%, 6%/9%, 3%/6%/9% or 3%/6%/10% ratings. The third rating is for difficult polar solvents like acetone and rubbing alcohol. Make sure your eductor or proportioner has settings to match the foam you carry. The 3%/3% and 6%/6% concentrates simplify training, with only one percentage setting to remember. The 3%/3% concentrates make more sense than the generation of 3%/6% concentrates that preceded them. Using a 3%/3% concentrate doubles your polar capability per can compared to a can of 3%/6%. The 3%/3% concentrates must be considered the only option for foam when you need to move large quantities of polar concentrate. The newest AFFFP is a 1%/3% concentrate. It allows application at 1 percent on hydrocarbons and 3 percent on polar solvents, and may be the ideal universal foam for an engine company if more than manufacturer produces it one day to bring the price down. That concentrate triples the hydrocarbon capablity per can or gallon carried compared to a 3%/3% or 3%/6% concentrates in th hydrocarbon setting. Right now the ideal for the engine company is a 1/2%/3%/3% concentrate. The 1/2% is used for Class A applications and the 3% setting is used for all flammable liquid risks. Finally, one foam that can do it all!
    Comparing AFFFPs to AFFFs
    A recent Federal Aviation Administration (FAA) report points out that different AFFFPs have an 80 percent to 250 percent difference in fire control times, or a 43 percent to 119 percent difference in extinguishment times and a 23 percent to 51 percent difference in burnback times on normal hydrocarbons. Remember, the brand you buy is just as important with AFFFPs as it is with AFFFs.
    When comparing AFFFPs to AFFF's, the FAA found in almost all cases that AFFF worked significantly better and was cheaper to use on hydrocarbon fires. Everyday AFFF is 5 percent to 268 percent faster in control times than AFFFPs, and 17 percent to 155 percent faster in extinguishment times. AFFFPs are sold as a "do-everything" foam, but may not be the best choice if hydrocarbons are of great concern in your area. If you need to carry an all-purpose agent, you'll have to live with reduced performance.
    There are as many as 35 ways to keep an everyday foam eductor from working (see "Why Eductors Fail,Fire Rescue Magazine June 97). The use of AFFFP offers one more way. One manufacurer points out that, "All nozzle/eductor pairs should be tested prior to use in order to determine suitability."
    AFFFPs are thicker than standard foams and, consequently, harder for an eductor to pick up than AFFFs or other foams. AFFFP, typically proportions 18 percent lower than AFFF under the same conditions. Depending on the eductor, engine pressures may have to be in the 300 psi range to begin to pick up foam. One manufacturer point out that a 95 gpm eductor set at 6 percent with AFFFP foam will only pick up 3.7 percent foam. In the 3 percent setting the eductor will only pick up 2.2 percent. Eighteen percent lower may be typical, but it could also be as much as 38 percent lower. This should concern every firefighter walking into an unforgiving polar solvent. Many modern foam injection systems don't get along with thick AFFFPs either. It's always a good idea to talk to someone who is running the same foam in the system you intend to own-before you own it.
    Several manufacturers recommend the use of U.L.-listed nozzles and eductors. They say, "There are numerous foam hardware components without U.L. listings that cannot be listed for use with any AFFF agent." U.L. listing cards show wide pressure ranges and induction rates for the same eductor when you change to an AFFFP concentrate from an FP, AFFF or FFFP. Don't buy AFFFP until you have seen the U.L. listing card to ensure it will work with your eductor or foam system. Some eductors work fine; the key is research. As one vendor says in their literature, "All nozzle/eductor pairs should be tested prior to use in order to determine suitability."
    Matching nozzles can be just as tough as matching eductors with AFFFPs, One manufacturer points out that certain specifically designed nozzles should be used with AFFFP foams. "If these nozzles are not available, a good, low-expansion nozzle may be used, but it will be less effective. Non-aspirating nozzles should not be used."
    One 3%/5% AFFFP can be used with low-, medium- and high-expansion nozzles. The use at high expansion opens up a new world of fire and vapor suppression on irregular surfaces, such as warehouses, storage areas with pallets. and open tanks. This type of AFFFP will suppress ammonia, chlorine and other hazardous vapors for extended periods. The significance of this new high-expansion AFFFP is only now being fully explored, and it may become the standard AFFFP.
    AFFFPs produce a plastic-type barrier that can be pulled away unintentionally from under the foam blanket. The manufacturers recommend repairs to any disturbed area as soon as possible. Film formation cannot occur on fuels that are 10 percent to 15 percent or more polar in nature.
    AFFFPs commonly become gel in foam tanks and in 5- and 55-gallon containers. This can be due to contamination or, more often, to high- or low-temperature storage. These foams should be stored in the 35- to 120-degree temperature range. For example, do not store AFFFP foam cans or apparatus storage tanks near engine exhaust, exhaust cowlings or in direct sunlight. Most AFFFPs cannot be stored in vented apparatus foam storage tanks because phase separation can occur, requiring a shovel to remove the foam from the foam tank. If you intend to use this type of concentrate, talk to other fire departments that are currently using it to find out how they keep it from turning to gel. Manufacturers of AFFFPs will generally replace the foam at no charge if it gels. You need to know if the foam has gelled before the day of the spill, though. Sending samples to the manufacturer yearly, in accordance with NFPA and UFC standards, is important to ensure that your foam will perform as advertised. If you intend to run polar foams, make sure your foam tank lid is removable.
    A Look at FFFPP
    The eighth foam is film-forming fluroprotein polar foam (FFFPP), which was introduced in the early 1980s. It does everything FFFP does, but will also work on polar solvents. Currently, this is the only foam available with all three U.L. listings for foam concentrates. It is a protein-base AFFF, a fluroprotein foam and a polar foam all at the same time. It is available in a 3%/6% and 3%/3% concentrate and can be premixed for long periods. This allows fireground educting at higher percentages, which should allow greater security after knockdown. It would also allow premixing in tankers or folding tanks when high-flow proportioning or educting equipment is not available. FFFPPs build a visible aqueous film, not an invisible film like AFFF and AFFFP.
    Polar foams can be subsurface-injected on hydrocarbon fires. Mobil Oil Corp., recommends injecting fluroprotein 3 percent concentrates at 4 percent; AFFF 3%/6% polar foams at 2 percent; FFFP at 3 percent and FFFPP 3%/6% and 3%/3% can be injected at 1 percent. When you compare the costs of the concentrates, FFFP is an incredible value.
    Fires rarely occur in diked areas with the fuel floating on water, and over-application is rarely achieved. If this sounds like the everyday pit fire, it is. In this case, the real test is whether the fuel burn out before you are ready to put it out. The fuel doesn't get hot because the water is absorbing all the heat. Hot metal doesn't exist. Foam can't run off because it's being held hostage by the dike. Rarely is a volatile hydrocarbon burned because of cost. You need to be serious about putting out this kind of fire. Plunge the foam, applying it roughly on the fuel surface. Use it in conjunction with cooling streams; use it on hot fuels and surfaces; make the foam talk. Depending how you test your foam, you may be in for a surprise one day. Many flammable-liquid fires burn out or go on for days. So-called "good stops" often use as much concentrate gallon-for-gallon as fuel burned.
    Keys to Success
    The correct foam or foams, the correct nozzles and proper application are the keys to fighting certain fires. Five-minute decisions can haunt you for 30 ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ????????????????????????????ction with an air aspirating foam nozzle is the ultimate!
    Tests conducted by A.A. Briggs and J.S. Webb of the Fire Research Stat?????????????????????????????????????????????? ?????????????????????????????????????????????????? ????????????????????????????????0 percent. Until the early 1980s there still were only two choices: speed of detergents or the security of proteins.
    Triple FPs
    ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????? available in 3 percent and 6
    percent concentrates. FFFP is a protein- or detergent-based foam that has an
    Underwriters Laborat??????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????????
    fluroprotein properties.

    Protein-based FFFPs don't have the weaknesses of detergent-based AFFFs.
    One manufacturer says FFFPs ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????? knockdown almost as quickly as AFFF. FFFP foam
    has substantially better vapor suppression than AFFF, with blanket stability
    al???????????????????????????????????????????????? ?????????????????????????????????????????????????? ??????????????????????????????-expansion nozzle against low-level controlled-burning
    liquid natural gas lasted for 15 minutes, whereas detergent foams lasted ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ????????????????????????????nt speed
    or safety.

    Making the Decision
    Testing at the Fire Research Station demonstrated that FFFP would control
    unleaded gas??????????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????___?___________?__ _________?___________?___________?___________? ___________?___________?___________?__________ ____A_A_?????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????????5 seconds. If speed of complete extinguishment is
    important, FFFP is three times faster, and therefore safer, than AFFF. An FFF??????????????????????????????????????????????? ?????????????????????????????????????????????????? ??????????????????????????????? also is listed at the lowest
    rate for hydrocarbon spill fires, as is AFFF.

    If absolute speed is a priority, AFFFs are faster ?????????????????????????????????????????????????? ?????????????????????????????????????????????????? ????????????????????????????understand the concept. Top-side application on petroleum tank fires and crash
    fire rescue applications are different than spil?????????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????? engine company, you don't have time to engineer the fire out; you must
    fight the fire out or wait.

    AFFFs and FFFPs do not re???????????????????????????????????????????????? ?????????????????????????????????????????????????? ??????????????????????????????___?___________?___ ________?___________?___________?___________?_ __________?___________?___________?___________ ___A_A_??????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????????? is where the foam bubble should come in.

    If you insist on subscribing to the concept of non-aspirated foam, then
    immediately??????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????????????ozzle aqueous foam lobby has missed the
    point. Speed without safety is reckless and irresponsible. If you truly subscribe
    to s????????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????hemical (twin agent)
    through the same turret or handline. Testing has shown the best dry chemical
    can achieve knockdown as muc??????????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????unction with foam in aircraft spill
    fires and those in bulk storage tanks have already resulted in scores of close
    calls, deat?????????????????????????????????????????????? ?????????????????????????????????????????????????? ????????????????????????????????mmediate application of fluroprotein foam
    through a foam nozzle, which is more effective than reliance on film formation
    alone????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????vered with two foam
    tanks one for Class A and another for Class B agents. It is not all that difficult to
    have two Class B tan??????????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????he
    problem with a medium-expansion nozzle.


    FFFP would allow one foam to do both without modifying the apparatus or the incon????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????t made by a medium-expansion nozzle is what we owe the public. Unfortunately, this essential tool is lacking at airports and the??????????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????ly on hydrocarbon fuels such as naptha (unblended gasoline), diesel oils, etc. They are effective on polar hydrocarbon blends, i????????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????ose from foams six, seven or eight. Future Environmental Protection Agency (EPA) clean-air standards will one day increase polar????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????????d hazardous materials awareness, that eight of 10 hazmat calls concern flammable liquids.
    Polar solvent foams build two kinds of???????????????????????????????????????????????? ?????????????????????????????????????????????????? ?????????????????????????????? solvents require deep foam blankets for vapor suppression. Any break in the foam blanket could cause the fire to reignite. Pola?????????????????????????????????????????????? ?????????????????????????????????????????????????? ????????????????????????????????el fire out with a fog nozzle. Although some manufacturers say it works, even if you were able to put the fire out, you might no???????????????????????????????????????????????? ?????????????????????????????????????????????????? ??????????????????????????????s on hydrocarbons. Another manufactuer says, "In the case of polar solvents, gentle application using an air-aspirating foam noz??????????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????erm method of application.
    Pros and Cons
    Foam six is a fluroprotein polar foam (FPP) and was introduced in the mid 1960s. It doe??????????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????er.
    Foam seven is an aqueous film-forming polar foam (AFFFP), that was introduced in the mid-1970s. It does everything AFFF does?????????????????????????????????????????????? ?????????????????????????????????????????????????? ????????????????????????????????irst percentage rating is for hydrocarbons. The second is for polar solvents. So if you have a fire involving naptha, or straigh??????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????????6% concentrates simplify training, with only one percentage setting to remember. The 3%/3% concentrates make more sense than the??????????????????????????????????????????????? ?????????????????????????????????????????????????? ???????????????????????????????o a can of 3%/6%. The 3%/3% concentrates must be considered the only option for foam when you need to move large quantities of prisk someone's life.
    24. Incorrectly labeled eductor: They are out there and could be stamped 60 gpm and be 95 gpm. The metering valve could be the wrong one for your unit, etc. Proper testing of life-saving equipment is the only way to know.
    25. Pickup tube has a shut-off: If you've added a shut-off to the pickup tube, remember that it needs to be fully open to work.
    26. No vent hole in the foam can: In many cases, it is quicker and easier to punch a hole in a can with an axe than try to remove the foam can lid, because most fire trucks don't carry a foam can wrench. If you punch a hole with an axe, make sure it is big enough to allow air flow around the pickup tube.
    27. Metering valve closed or in the wrong position: Some valves read on the knob side and others read on the thread side. Lack of use or familiarity could ensure it is not set for proper use. Many departments preset the metering valve after flushing to eliminate setting it on the fire ground.
    28. Plugged inlet screen: Some of the better eductors have an inlet screen to protect the water inlet and or the foam metering valve. Clogging results in a loss of flow or a reduction in concentrate pickup.
    29. Over-pressurized eductor: If you over-pressurize a variable eductor, you can blow the guts out of it. If it is put away after the vent, it won't work when it is needed. Any leakage around the center of the unit is a sure sign of over-pressurization damage.
    30. Mixing foam concentrates: Many foam concentrates will gel on contact with other foam concentrates. Polar AFFFs can gel with other polar AFFFs; protein and fluoroprotein foams can gel with polar AFFFs; and AFFFs can gel with polar AFFFs. It is OK to mix concentrates and types of foam on the fire through foam streams, but not in concentrated form in the eductor. In some cases, the clog cannot be cleaned out.
    31. An open bypass value:. If you are using a bypass eductor, it can have all 30 problems listed above, plus it has one more valve that must be closed all the way to pick up foam. It must also be free of obstructions.
    32. Fixed eductor and bypass eductor systems also have a few built-in potential foam pick- up problems. Because these systems are rarely if ever used, you must make sure written color-coded instructions exist and are followed on scene. The correct foam concentrate handle needs to be pulled; the eductor handle needs to be open; the foam tank needs to have something in it; the foam tank has to be vented properly; the foam in the tank cannot have gelled; the metering valve needs to be stem; and the plumbing to the eductor cannot have too much friction loss or too many elbows or it will not work.

  3. #3
    John_Ford
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    Mike, Excellant post. Could you E-Mail this to me as The format won't allow me to print it out without cutting off the side of the post? I would like to use this for a foam class. I will tell them where I got it from.

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    Email address?

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    Thank you Mike C for this excellent post. I would also appreciate if would e-mail this article to me. It will be useful to me in preparing classes in the future.

  6. #6
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    If you go to the bottom of the thread and click on " Printable Version" it will print exactly what you want. Thanks, MIKE C
    Bob Compton
    IACOJ-Proud
    IACOJ-HALL OF FAME-2003

  7. #7
    District Chief
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    Another good source for foam information is Mr. Jim Cottrell

    Jimcott@aol.com

    He is very very well versed and the by far the most knowledgable peron I have met on foam.
    09-11 .. 343 "All Gave Some..Some Gave ALL" God Bless..R.I.P.
    ------------------------------
    IACOJ Minister of Southern Comfort
    "Purple Hydrant" Recipient (3 Times)
    BMI Investigator
    ------------------------------
    The comments, opinions, and positions expressed here are mine. They are expressed respectfully, in the spirit of safety and progress. They do not reflect the opinions or positions of my employer or my department.

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