LETTERS TO THE EDITOR

LETTERS TO THE EDITOR

Urban myth

Let me take this opportunity to thank you for the excellent article “Anatomy of an Urban Myth” by Frank L. Fire (August 1992). It most accurately depicted how the events occurred regarding this costly episode.

I am happy to inform you that L.E.S. Tim Scherer, aka Deputy Scherer, has been identified as an employee of the Escambia County (EL) Sheriffs Department. This has been confirmed with Mr. Scherer’s supervisor, as has the fact that Mr. Scherer was the author of the original “Intelligence Bulletin.”

To clarify one point, it was the insurance company supervisor who made the decision that the original bulletin came from this office, and his decision was based solely on the fact that the wrecker driver acquired the bulletin while on a trip to Alabama.

I must admit that in attempting to find some humor in this lengthy chain of letters, bulletins, memos, telephone calls. NCIC messages, and faxed communications, 1 arrived at the conclusion that had the wrecker driver become pregnant while in Alabama. we most probably would have received credit for that also. On the other hand, since this began less than nine months ago, that. too. may occur any day. Again, thank you for your efforts to clear the air regarding this erroneous information.

John S. Robinson State hire Marshal State of Alabama Department of Insurance Montgomery, Alabamci

Numbers game

The article “The Numbers Game” by Peter G. Sparber (September 1992) was very interesting; however, 1 believe one very important statistic that is critical to demonstrating performance is continually omitted by fire departments in their reporting. Most fire statistics document fire loss. Of equal or more importance is loss prerented or property saved.

A fire department that has reduced its fire loss total may be looked at as no longer needing as much budget. “You did not have as many fires so you do not need as big a department.” On the other hand, a big loss may indicate to those who control the bucks that the department is not doing its job. Only when the loss figure is related to property value can proper comparisons be made. A S30,000 dollar loss in a home may sound bad, but if the home is worth S250,000 it probably indicates a good stop.

The property-saved information is critical to showing department performance. An aggressive fire prevention and fire attack program would show a high percentage of property protected or saved compared with fire loss. This should provide information to justify addition to the fire prevention budget. Possibly the NEIRS should provide in its inquiry’ forms a place to show this statistic.

If a department has been performing well but has taken severe budget cuts, it is likely the fire loss will increase and the ratio of property saved or protected will go down. This will provide direct evidence of the cost to the citizens of the cutbacks if the ratio of loss to value increases.

John Fisken Safety ■ Adm i 11 istrator Safety, Health & Environmental

Affairs

Boeing Defense & Space Group Seattle, Washington

Class A foam

I am writing to comment on “The Pros and Cons of Class A Foam” (July 1992). I have been researching Class A foam for the past 12 months by talking with manufacturers and distributors, research labs, and fire chiefs who currently are using Class A foam. Also, I have been getting as much hands-on training as I can. This has given me a comprehensive background in Class A foam and its hardware.

In the article the authors state, “Class A foam will crystallize and separate if stored in temperatures below — 10°F.” While this is true for most Class A foam concentrates, it is not true for all. Silvex, developed by Ansul, will remain in a useful state up to — 25°F. This statement may discourage departments in the colder regions of America from trying Class A foam because they feel it will not be of use to them all year round.

I have read numerous articles over the past year that deal with Class A foam and have realized that most, if not all, talk mainly about compressed air foam systems (CAFS); very’ few have discussed either eductors or proportioners to any degree. I feel that you are leaving out very important information that needs to be discussed. My department is currently using eductors to deliver Class A foam at 0.5 percent by remixing the fivegallon pails of concentrate. This is a suggestion that should be shared with other departments. A lot of departments do not have the budget to afford a CAFS and get discouraged because of this. Most departments could try Class A foam with current equipment and upgrade as they get the budget.

The article, however, was the first to mention the biggest downfall of CAFS, and that is that if something were to go wrong with the compressor, the nozzle may only be flowing 30 to 40 gpm. One negative with regard to the CAFS I found in my research is that you must be veryknowledgeable to run it effectively. If this unit is placed in a volunteer department that never knows exactly who will be pumping at a scene, it can be a major problem. Most of those departments would prefer a “no brainer.” That is, can anyone at 3 a.m. run the unit with expert proficiency? With the CAPS, the answer is NO!

I do not mean to sound negative about the CAPS, but so much energy is put into letting the firefighting community know about this system that the other equally effective systems are forgotten. The CAP’S was designed for the Department of Forestry. The people with whom 1 have spoken have said great things about this system when dealing with the urban/rural interface, but not all departments have this problem; in fact, very few fight actual forest fires.

Michael L. Brown Firefighter Saginaw Township (MI) Fire Department

The Class A foam articles in the July issue were excellent! We have used Class A foam in structural firefighting for more than a year and, as the articles identify, quantifying results need to be completed.

Our firefighters fully realize that Class A foam is making their job easier, and fires are being extinguished more quickly. Visiting firefighters ask our folks their opinion of Class A foam. Invariably the reply is, “Something is happening!”

“We” need quantification to verify the positive experiences occurring.

F.C. Windisch Chief

Ponderosa (IX) Volunteer Fire Department

I would like to offer some comments on “The Pros and Cons of Class A Foam.”

• “Class A foam can be used in a direct fire attack or as a backup line to a conventional water attack line.” This is not a good way to employ Class A foam, either in terms of fire suppression or fire department operating policy. As Class A foam has a great potential for reducing the danger of firefighting by reducing the exposure of the firefighter to the heat and toxicity of a fire and as it also has the potential to reduce environmental damage by reducing the amount of water needed and consequently reducing the runoff of polluted water, foam should be used during initial attack on all fires for which use of Class A foam is indicated as suitable. Using Class A foam as a backup to a conventional water attack line negates many of the advantages of foam. In addition, it is possible that applying untreated water before the foam actually will reduce the effectiveness of I the foam by diluting the foam applied.
• While it is true that Class A foam | can be mixed in the booster tank, this I technique is strongly discouraged as, I among other things, it does not allow I adjustment of the foam proportion, may cause damage to certain tanks,and can froth over the side of the apparatus when responding on i bumpy roads. Class A foam is biodegradable and begins to break down I once it is mixed with water. Therefore, if the concentrate is mixed in the booster tank and left there for more than 24 hours, it is no longer the material the vendor provided, so the manufacturer’s information may not apply to the solution when it is applied to the fire, and it may not even work.
• “Class A foam is very effective for overhaul and rekindles, and for attic and grass fires.” This seems to say that foam is not effective for interior structural fire attack, which is simply not true. The ISFSI, as well as many others, has amply demonstrated that both nozzle-aspirated and compressed-air foam are very effective for such applications.
• “Several studies referenced the corrosive aspects of Class A foam in a 100 percent concentrate.” While it is true that Class A foam concentrate does have certain corrosion problems, 100 percent concentrate is never induced into the fire pump system in any Class A foam application system of which I am aware. Suction-side mixing, such as batching or other devices, is not the proper way to use Class A foam in structural applications; it should be done with discharge-side devices such as eductors or proportioners and not with around-the-pump or other systems that induce foam into the pump. It also should be noted that even with suction-side devices, it is the 0.1 to 0.9 percent solution that enters the pump and plumbing, not the concentrate. It is true, however, that equipment needs to be flushed after use with Class A foam, but then this is true with most fire suppression chemicals.
• “Studies by the U.S. Department of Agriculture Forest Service reflect the need to provide protective equipment for personnel using Class A foam.” It should be realized that the source of this quote is an agency that has wildland fire protection responsibility, not structural responsibility; any structural fire department considering the adoption of Class A foam that is not already providing this common-sense level of protection is guilty of dereliction of duty. Thus, the use of protective gear with Class A foam should be of no additional concern to a structural fire department.
• “Finally, it is important for firefighters to wear SCBA and protective clothing to prevent breathing vapors of products of combustion.” I submit that wearing full protective gear is mandatory for all structural firefighting; the use of Class A foam does not change this one iota.
• On the matter of increased radiant heat inside a structure after fire suppression with Class A foam, this is, again, a nonissue: As Class A foam application so greatly reduces the exposure of the firefighter to the heat of the actual fire, the health risks of fire suppression are vastly reduced by using foam. Removing the residual heat sometimes found after such fire suppression is easily accomplished under conditions much safer than those found during actual suppression operations.
• “.. .since tests have demonstrated that the direct application of foam on a flame results in rapid reduction in the foam blanket, adjustments must be made and personnel retrained in application techniques.” First, this fails to take into account that application of foam often knocks down, and even extinguishes, the fire so that it is no longer necessary to apply foam at all; second, training with any new equipment or technology is always needed, so this is hardly a drawback in considering the adoption of Class A foam.

The authors fail, however, to note that the adoption of CAFS must be accompanied by some very extensive training. CAFS is so different from anything currently done by the structural fire service that it is mandatory to institute an in-depth training program before using compressed-air foam at the scene of an emergency. The work the ISFSI has done with CAFS has shown that at least some of this training has to be done in acquired structures, rather than in burn buildings, if a true understanding of fire suppression with CAFS is to be obtained. (It is, or at least should be, obvious that any such live fire training must be done in accordance with NFPA 1403 and 1500, among other standards that apply to this type of exercise.)

• “.. .hose kinks significantly reduce the pressure in the hose.” This is true with plain water hoselines, not just Class A foam lines. Where it is a serious issue is with compressed-air foam systems, where the pressure of the water and air in the hoseline is not sufficient to remove kinks, and the kinks not only reduce the pressure but also may affect the quality of the foam delivered to the fire; again, however, this is simply a question of proper training, not a reason for not adopting foam technology.
• “Should the foam-generating mechanism break dow n.. .an interior structure attack using a low -pressure stream or CAFS could leave the attack team with an insufficient water flow that provides limited protection and decidedly less than the critical flow rate.” There are several issues to be considered here. First, nozzle-aspirated foam does not require low pressure lines; they can be used with the existing nozzles in use by most structural fire departments with no reduction in pressure whatsoever; in addition. in this type of application, loss of foam simply will leave the hose crew with a “normal” water attack line. Second, the critical flow rate with nozzle-aspirated foam is basically identical to that used for nonfoam lines, so that is not an issue. With compressed-air foam, however, there may well be a problem, because the critical flow rate for CAFS has not been established, and the line in use may very well be flowing water at a rate well below that normally employed for nonfoam applications.

This, however, leads me to another point in the article, and that is the question of not even using a nozzle with CAFS. While it is true that a nozzle is not actually needed, recent work by the ISFSI and others in interior structural firefighting with compressed-air foam has shown that the use of a straight-stream tip on the ball valve at the discharge end of the hoseline is required to generate the highest quality of foam possible and to ensure that the foam is properly delivered to the fire. A formula now exists for determining both the hose and tip size when using CAFS handlines. If the foam system should break down under these conditions, the pump operator quickly can increase the water flow, thus reducing the danger to the attack team. In considering the adoption of Class A foam, remember that hoselines break, nozzles clog, and water supplies and pumps fail also when Class A foam is not being used. Foam is not a panacea, but its adoption should not be foregone due to perceived problems that do not really exist.

• “A review of the MSDS on Class A foam reveals that spills of material should be collected for disposal. The suggested method of disposal is incineration.” First, the idea of physically removing spills applies to the concentrate; second, it applies to removing the material from waterways. Class A foam is biodegradable; spills, if they should occur despite common-sense handling precautions, are not a serious problem, except where the chemical might kill fish and other aquatic life. I do not know where the suggestion arose that incineration is required, and I doubt that it is necessary. It should also be realized that Class B foam agent spills also pose dangers; this has not kept the fire service from using it.
• “A guide based on fuel type was established.. that is vague and needs more measurement.” It should be clearly understood that this article refers strictly to wildland fuels, not structural fuels; the terms used in the article cited certainly are understood by professional wildland fire suppression personnel. The terms have no relevance to structural fire suppression.
• Much seems to be made of the use of new protective equipment in conjunction with Class A foam: “This equipment, coupled with the seemingly ‘perfect’ fire suppression agent Class A foam, could create a scenario where an inadequately trained or inexperienced firefighter could penetrate too deep into an interior fire and be overcome by flames, heat, or smoke.” I fail to see why the use of Class A foam could create such a scenario; it already exists, far too often! In addition, anyone making the claim that Class A foam is a perfect fire suppression agent is making outlandish claims that cannot be substantiated. Class A foam is a valuable addition to the fire service’s arsenal, but it is simply another firefighting tool, not “the answer.”
• In the sidebar “What Is Class A Foam and How Does It Work?” reference is made to those who say it is black magic. I suspect that this is taken out of context from statements I make in teaching the ISFSI’s introductory class on structural fire department use of Class A foam. While I do use the words “black magic,” they are used to make it clear to the students that no one, myself included, has all the answers about Class A foam, and specifically about CAFS. When 1 use the term “black magic,” it is only to say that much of the methodology of how compressed-air foam actually extinguishes fires is unknown. In its series of live fire burns using CAFS, the ISFSI consistently has shown the ability of compressed-air foam to extinguish fires at water-flow rates far below those indicated by existing fire department rule-of-thumb experience and has discussed the theories relative to critical rates of flow. These results are well documented. The “black magic” part refers to the fact that we don’t know why CAFS extinguishes fires with such low flow rates; that it does so continues to be amply demonstrated.

While there are other items in this article that I might take issue with, I believe that this letter covers all of the major points. I do not feel that this article fairly represents the subject of Class A foam.

John Liebson

Western Regional Director

International Society of Fire

Service Instructors

Santa Fe. New Mexico