Ethanol Emergency Response Coalition
A series of performance fire tests were conducted on denatured ethyl alcohol, ethanol, (95% ethanol that was denatured with 5% gasoline) and on gasohol (defined by API as regular unleaded gasoline with up to 10% by volume ethyl alcohol). The purpose of the test program was to evaluate the effectiveness of various foam concentrates and other water additives on these two types of fuels.
The following generic foam concentrates and water additives were evaluated:
A. Alcohol Resistant AFFF (AR-AFFF)
B. Class A Foam
C. Regular AFFF
D. Emulsifying Agent
E. Regular Fluoroprotein
F. Alcohol Resistant Film Forming Fluoroprotein (AR-FFFP)
Where possible, 3% versions of each of these agents were used.
All of the above agents tested were commercially available products and were not considered to be manufacturer or brand specific. Results, therefore, are for generic types or classes of foam agents rather than brand specific products. Personnel involved in the fire testing were not informed as to the brand or manufacturer of the agents being used but were informed as to the type of agent being used.
Fire testing protocols were based on the methods established for topside and sprinkler testing as outlined in UL 162; Standard for Safety - Foam Equipment and Liquid Concentrates; 7th edition.? This standard establishes fire test protocols for applying agent to the fire by various application techniques using specified application rates.? Application rate is defined as gallons per minute of unexpanded foam solution flow divided by the fire area. For example, a 50 square foot fire using a 3 gallon per minute flow rate would have an application rate of 0.06 gpm/sq.ft. UL defines agent applied directly to the surface of a burning liquid fuel as a "Type III" application. This application technique allows for plunging and submergence of the agent when applied to the fire. They further define a "Type II" application as a fixed discharge applied to a vertical surface so as to provide a more gentle application with minimal plunging or submergence. These Type II and Type III fires are classified as "top side" fire tests by UL. Generally, Type III applications are used for hydrocarbon fuels while Type II applications are used for polar solvents / water miscible fuels such as ethanol. Finally, sprinkler application of the agent allows for testing out of either air-aspirated or non-aspirated sprinkler devices as would be found in fixed protection for loading racks or other fuel transfer areas. For both top side and sprinkler tests, UL 162 requires not only successful extinguishment but also a level of resistance to re-ignition and burn back (typically, simply called "burn back resistance").
All agents were evaluated on both fuel types. For ethanol fires, all agents were evaluated on both Type II and Type III fire scenarios. Any agent capable of passing either of these fire scenarios was further evaluated on a sprinkler fire. For gasohol fires, only Type III fires were conducted. Again, any agent capable of passing the top side test was further evaluated on a sprinkler fire.
Results for ethanol fires are summarized as follows:
I. Only Alcohol Resistant products (AR-AFFF & AR-FFFP) were capable of extinguishing any of the top side fire tests.
II. Only Type II fires were successfully extinguished with the two AR type products. The AR-FFFP required a higher application rate to extinguish the fire.
III. Of the two agents that were capable of passing the extinguishment requirements, only the AR-AFFF was capable of also passing the burn back resistance portion of the test.
?IV. Only the AR-AFFF was capable of passing all of the top side fire test requirements of UL 162 but only when using a Type II discharge scenario.
?Only the AR-AFFF was capable of passing the sprinkler test with non-aspirating sprinkler heads. Each manufacturer's UL Listing will have to be referenced relative to the proper application rate for a sprinkler system.
Results for gasohol fires are summarized as follows:
I. Only AR-AFFF and Regular AFFF were capable of extinguishing the Type III fires at the recommended UL test rate of 0.06gpm/sq.ft.
II. An increased application rate was required for the AR-AFFF to pass the burn back portion of the test.
III. Regular AFFF was not able to pass the burn back requirement even at an application rate as high as the NFPA minimum application rate for spill fires of 0.10 gpm/sq. ft.?
IV. AR-AFFF was able to pass sprinkler testing on gasohol using non-aspirating sprinkler heads.
V. Regular fluoroprotein foam was able to pass the UL sprinkler test with air-aspirating sprinkler heads.
I. Denatured ethyl alcohol fires can only be extinguished with AR type foams (AR-AFFF & AR-FFFP). All other types of foams or water additives are ineffective as the foam blanket is destroyed when it strikes the fuel surface.
II. AR type foams must be applied to ethyl alcohol fires using Type II 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 very shallow (ie. ? inch or less).
III. Gasohol fires may be extinguished using conventional AFFF or AR-AFFF but increased application rates may be necessary especially for prolonged burn back resistance. A TypeIII direct application with these foams onto the fuel surface may be used with gasohol.
IV. Non-aspirating sprinkler head systems may be used with AR-AFFF for ethyl alcohol fuel fires and for gasohol fires such as in loading rack installations. All other foams proved to be ineffective at the application rates tested.
?V. Use of regular fluoroprotein foam through air-aspirated sprinkler systems at standard design rates proved to be effective on gasohol fires but not on denatured ethyl alcohol fires.?
VI. Overall, AR-AFFF proved to be the most effective and most versatile agent tested. It was the only agent that was successful in all fire test scenarios.
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