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D EPAR TM EN T OF THE NAVY NAVAL RESEARCH LABORATORY 45SS OVERLOOK AVE SW WASHINGTON DC 2M75-S320 IH E PL Y A c r C P TO 3900 Ser 6180/0303 4 August 2004 From; Commanding Officer, Naval Research Laboratory To; Commanding Officer, Naval Facilities Engineering Service Center, Port Hueneme, CA (Code ESC421 R. Lee) Subj: FIRE FIGHTING PERFORMANCE OF FLUOROSURFACTANT-FREE ALTERNATIVES TO AQUEOUS FILM FORMING FOAM (AFFF): INITIAL EVALUATION OF 3M RF6 AND A DEVELOPMENTAL FORMULATION End: (1) Two copies o f subject report 1 Enclosure (1) is forwarded for your information and retention. 2. The Naval Research Laboratory point o f contact is Dr. Ronald Sheinson, Code 6185, (202) 404-8101 and email Sheinson@code6185.nrl.navy.mil. WARREN W. SCHULTZ By direction Copy to: NAVFACHQ (FES C. Glover, Jr) COMNAVSEASY SCOM (Code 05P4 D. McCrory, D. Barylski) OPNAV (Code N762M2 T. Harmon) DESC (DESC-FQ D. Whitney) DLA (DSS-IP N. Metha) Distribution Authorized to US Government Agencies and their Contractors Only; All other requests shall be forwarded to: Commanding Officer Naval Research Laboratory, Wash. DC. THIS INFORMATION HAS NOT BEEN APPROVED FOR PUBLIC RELEASE. 6180A:RS 4 August 2004 FIRE FIGHTING PERFORMANCE OF FLUOROSURFACTANT-FREE ALTERNATIVES TO AQUEOUS FILM FORMING FOAM (AFFF): INITIAL EVALUATION OF 3M RF6 AND A DEVELOPMENTAL FORMULATION Ronald S Sheinson Navy Technology Centerfo r Safety and Survivability Chemistry Division Scott Ayers Geo-Centers, Inc. Arlington, VA Enel (1) to NRL Itr 3900 Ser 6180/0303 Distribution Authorized to US Government Agencies and their Contractors Only; All other requests shall be forwarded to: Commanding Officer Naval Research Laboratory, Wash. DC. THIS INFORMATION HAS NOT BEEN APPROVED FOR PUBLIC RELEASE. US00000834 FIRE FIGHTING PERFORMANCE OF FLUOROSURFACTANT-FREE ALTERNATIVES TO AQUEOUS FILM FORMING FOAM (AFFF): INITIAL EVALUATION OF 3M RF6 AND A DEVELOPMENTAL FORMULATION Introduction The discontinuation o f perfluoro-octanyl sulfate (PFOS) based chemistry by the 3M Company was a significant event for the fire fighting community. PFOS chemistry was found to be environmentally persistent, bio-accumulative, and toxic. 3M used this technology to produce its Military Specification MIL-F-24385F (MilSpec) [1] certified aqueous film forming foam (AFFF). 3M has been a major supplier o f AFFF to the Department o f Defense since AFFF's joint development with NRL in the 1960s, but due to environmental concerns 3M has withdrawn their AFFF products. In fact, the Environmental Protection Agency (EPA) placed PFOS-based chemicals under a Significant New Use Rule (SNUR) and is investigating potential environmental issues for other chemistries used to produce the remaining MilSpec qualified AFFFs. Further, the European Union, United Kingdom, and Australia placed controls on fire fighting foams, and proposed regulations are increasingly restrictive. These events have led the Naval Facilities Engineering Service Center and the Navy Technology Center for Safety and Survivability (NTCSS) o f the Naval Research Laboratory (NRL) to study new, less environmentally damaging fire-fighting foam options including fluorosurfactant-ifee foams. Fluorosurfactant-free fire fighting foam formulas do not carry the burden o f extremely long-lived components and degradation products. Hence, they do not have the same persistence and bioaccumulation concerns, as the current AFFF formulations. The test plan for this work is found in reference [2]. Objective The objective o f this work was to evaluate the fire performance o f two fluorosurfactant-free fire fighting foam formulas from the 3M company, RF6 and a formulation under development herein referred to as Dev3. RF6 is a 6 % concentrate to be mixed with water, while Dev3 is a 3 % concentrate. Fire performance evaluation followed the MIL-F-24385F protocol; a baseline 3 % MIL-F-24385F-approved AFFF was also tested as a control. Test Parameters This test series was conducted at NRL's Chesapeake Bay Section (CBD) facility near Chesapeake Beach, MD. The smaller fires were conducted within a calorimetry facility with an exhaust hood removing the products of combustion. The larger fires were conducted outside on a large concrete pad. All the foam and remaining fire fuels were contained in holding tanks. A foam generation system used in past MilSpec qualification testing was utilized for this test series. The system consisted o f a 10 gallon holding tank pressurized by nitrogen from the top. A hose line o ff the bottom o f the tank led to an air-aspirating nozzle, which supplied 2.0 gallons per minute o f foam at 100 psi. Prior to each day's testing the system calibration was checked. I A stopwatch was the primary measurement device used. Fire out times and bum back times were recorded from this. Other maximum time-allowed events set forth in the MilSpec such as fuel pour were verified with the stopwatch. A video camera recorded each fire suppression test. Also a thermometer was used to check the temperature o f the solution, water base in the pan, fuel, and the air prior to each test. Variables There were five variables in this test series. Dev3 and RF6 were the primary foams studied, and MilSpec approved AFFF tests were conducted as controls. The foam solution strength was varied to examine the more difficult half-strength scenarios; as in the MilSpec protocols, the 6 % concentrate was mixed at 3 % and the 3 % concentrates were mixed at 1.5 %. One Dev3 double strength test was conducted outside the test matrix to assess performance. The water salinity was varied to look at the effects o f both fresh and salt water. The fire fuel was varied to explore the foam performance on jet fuel as well as gasoline. Finally the fire area was varied to learn the foam performance in difference energy release rate cases. The test matrix and applicable MilSpec criteria are detailed in Table 1. Table 1. Test M atrix and Applicable M ilSpec Criteria Foams Dev3, RF6, AFFF Dev3, RF6 Dev3, RF6 Dev3, RF6 Dev3, RF6, AFFF Dev3, RF6, AFFF Foam Strength Full Full Half Half Full Full Water Salinity Fresh Salt Fresh Salt Fresh Fresh Fire Area 28 ft2 28 ft2 28 ft2 28 ft2 28 ft2 50 ft2 Fire Fuel Gasoline Gasoline Gasoline Gasoline JP-5 Gasoline Fire Out Time <30 s <30 s <45 s <45 s . <55 s Burn Back time >360 s > 360 s > 300 s > 300 s - >360s Test Procedure The pretest procedure included rinsing both the foam generation system and fire pan to remove foam from the previous testing. Once the previous foam had been properly removed, the solution was mixed into the foam generation tank. Finally water was poured into the fire pan to create a level surface; about ten gallons o f water was placed in the 28 ft2 fires and about fifteen gallons was placed in the 50 ft2 fires. The test procedure began by starting video recording. The fuel was then poured into the pan within the MilSpec requirement that the fuel be poured in thirty seconds. The fuel was the ignited by match and allowed to spread across the fuel surface. 500 mL o f gasoline was used as an accelerant to facilitate ignition of the JP-5. The fully established fire was allowed to bum freely for 10 seconds before the foam application began. The time needed for extinguishment was recorded. During the 50 ft2 fire, the estimated area coverage o f foam was recorded at 10, 20, 30, and 40 seconds and summed together for a "summation"; the MilSpec required a summation o f at least 320 for passing. The foam application in all fire cases continued for a total o f 90 seconds in preparation o f the bum back. One gallon o f gasoline in a one foot bum back pan was ignited and placed in the center o f the larger fire pan after foam application. The time needed for 2 the fire to bum back 25 % o f the fire surface was recorded. After that point the test ended, the video was stopped, and the post-test fire was extinguished. Test Results Full Strength, Fresh Water Results The full strength, fresh water test results are detailed in Table 2. The results show that both Dev3 and RF6 fell short o f the fire out times; however the RF6 was about 10 seconds closer. Also shown is that the RF6 preformed better than the AFFF in the bum back test exceeding the MilSpec criteria, while the Dev3 narrowly missed the criteria. Table 2. Full Strength, Fresh Water Average plus M inim um Fire Out Times and Average plus Maximum Burn Back Times Foam dumber of Fire Out Burn Back Tests Ave Min Ave Max MilSpec Requirement:________ < 3 0 ________ > 3 6 0 AFFF 4 30 25 431 444 Dev3 2 51 50 349 350 RF6 3 40 39 476 525 Full Strength, Salt Water Results The full strength, salt water test results are detailed in Table 3. The results were similar to the fresh water tests, both Dev3 and RF6 failed to meet the fire out criteria while the RF6 was much closer. The RF6 met the bum back criteria although it was much closer than the fresh water case. The Dev3 fell two minutes short o f meeting the criteria however. Table 3. Full Strength, Salt W ater Average plus Minimum Fire Out Times and Average plus Maximum Burn Back Times ,,Foam Number of Fire Out Burn Back _________ Tests Ave Min Ave Max MilSpec Requirement:________ < 3 0 ________ > 3 6 0 Dev3 1 - 67 - 240 RF6 2 43 41 370 372 3 US00000837 H alf Strength, Fresh Water Results The half strength, fresh water test results are detailed in Table . The RF6 performed well in this scenario, meeting both the fire out time criteria and bum back criteria. The Dev3 failed the fire out time considerably and was within 22 seconds o f meeting the bum back criteria. Table 4. Half Strength, Fresh W ater Average plus Minimum Fire Out Times and Average plus Maximum Burn Back Times p Number of Fire Out B urn Back ... am Tests Ave Min Ave Max MilSpec Requirement: < 45_______ > 300 Dev3 2 87 80 273 278 RF6 2 45 44 340 348 H alf Strength, Salt Water Results The half strength, salt water test results are detailed in Table . The Dev3 failed to extinguish the fire. The RF6 needed 18 more seconds than the criteria to extinguish the fire and was nearly a minute short o f the bum back criteria. Table 5. Half Strength, Salt Water Average plus Minimum Fire Out Times and Average plus Maximum Burn Back Times ,,Foam Number of Fire Out Burn Back _____________Tests Ave Min Ave Max MilSpec Requirement:______< 4 5 ________ > 3 0 0 Dev3 1 Not Extinguished RF6 1 - 63 - 245 JP-5 Results The JP-5 test results are detailed in Table 6. JP-5 is more difficult to ignite than gasoline and did require 500 mL of gasoline added gently on top of the JP-5 as an accelerant. The gasoline is consumed during the prebum period o f the test. Both the Dev3 and the RF6 performed similar to the AFFF in the extinguishment o f the fire. Both the Dev3 and the RF6 exceeded 360 seconds o f bum back protection. Table 6. JP-5 Test Results Foam AFFF Dev3 RF6 RF6 Fire Out Burn Back 18 X 18 389 21 560 18 X X - Not Attempted 4 US00000838 50 ft2 Results The 50 ft2 results (gasoline fuel) are detailed in Table 7. The Dev3 did not extinguish the fire; however it came close as evident by the criteria-exceeding summation. Experimental observation showed that the fire was knocked down but could not be completely extinguished. The fire continued to heat the fuel and the fire grew back in intensity. The RF6 was able to extinguish the fire, although it took 30 seconds longer than allowed in the MilSpec. While the bum back was very poor with the RF6 in this situation, the summation was acceptable. Table 7. 50 ft2 Average plus M inimum Fire O ut Times, Average plus M aximum Burn Back Times, and Average Plus Maximum Summation Foam Number of Fire Out Burn Back Tests Ave Min Ave Max MilSpec Requirement: <55 >360 AFFF 2 59 55 - 450 Dev3 1 Not Extinguished RF6 2 86 85 - 168 S um m ation Ave Max >320 358 363 - 340 342 349 Conclusion The objective o f this work was to conduct initial evaluation o f the fire performance o f two fluorosurfactant-free fire fighting foam formulations; not to perform the thorough testing employed for MilSpec certification evaluation. The developmental formulation (Dev3) did not meet MilSpec requirements in any test attempted. It was not able to extinguish the 28 ft2 fire under half strength, salt water conditions nor the 50 ft2 fire under full strength, fresh water conditions. The RF6 did meet the MilSpec in one test with half strength, fresh water for the 28 ft2 fire. The RF6 bum back protection in the 28 ft2 fire also met the MilSpec criteria in all tested conditions other than the salt water, half strength. The RF6 bum back protection was even better than the AFFF under fresh water, full strength condition. Overall both Dev3 and RF6 had more difficulty with salt water; and both Dev3 and RF6 had more difficulty with the larger fires, compared with AFFF. The Dev3 at full strength and RF6 at half strength under both fresh and salt water conditions performed similarly. Therefore we experimented with Dev3 mixed at double strength. Dev3 mixed double intended strength at six percent (for one test only) and RF6 at the same concentration o f six percent, performed similarly as seen in Table 8. 5 Table 8. Dev3 and RF6 C om parison Foam Number of Foam W ater Tests Strength Salinity Dev3 RF6 Dev3 RF6 DevF3 RF6 1 3 2 2 1 1 Double Full Full Half Full Half Fresh Fresh Fresh Fresh Salt Salt Fire Out Ave Min - 48 40 39 51 50 45 44 - 67 - 63 Burn Back Ave Max - 583 476 525 349 350 340 348 - 240 - 245 Overall the RF6 performed better than the Dev3 (at design concentrations) in all cases. While the RF6 did not meet the MilSpec fire performance requirements for the challenge fire scenarios evaluated, it may be satisfactory for challenge scenarios not requiring the very rapid, large fire capabilities provided by AFFF, especially for fresh water applications. The applicability o f nonAFFF products will depend on the specific fire protection needs, with MilSpec qualified fire fighting foam required for critical uses involving rapid personnel extrication or ordinance. Gasoline is the threat fuel specified in the MilSpec testing protocol. This presents a difficult challenge against which prospective fire fighting formulations need to prove themselves. Gasoline (Mogas) is employed within DoD, both on land and on weapons platforms. Some facilities may require fire protection only against higher boiling point, less volatile fuels. In this case, the less volatile JP-5 fire tests may be more relevant. Both the Dev3 and RF6 performance against the JP-5 fires was comparable to the AFFF performance. Acknowledgements The authors would like to recognize and thank our resident NRL firefighter John Farley and test assistant Clarence Whitehurst. We also acknowledge the assistance o f Bradley Williams and Charles Diehl, Darren Liang, Cynthia Chang, Brandon Finch and Robert Thomas, temporary employees while in college. We also acknowledge the help o f Ralph Ouellette o f HAI while observing the tests. This task was sponsored by Naval Facilities Engineering Service Center References [1] United States Military Specification "Fire Extinguishment Agent, Aqueous Film-Forming Foam (AFFF) Liquid Concentrate, for Fresh and Sea Water," MILSPEC MIL-F-24385F, 7 January 1992.2 [2] Sheinson, R.S. and Ayers, S., "Test Plan for the Fire Fighting Performance o f a Fluorosurfactant-Free Alternative to Aqueous Film Forming Form (AFFF): Initial Evaluation", NRL Ltr Rpt Ser 6180/0258, 6 July 2004. 6 US00000840 Appendix A: Results M atrix Table A. Test Results Compilation Test Fire Fire Fire Burn N um ber Foam Strength Salinity Fuel Area Out Back Summation 1.1 AFFF Full 1.2 AFFF Full 1.3 AFFF Full 2.1 Dev 3 Full 2.2 Dev3 Full Fresh Fresh Fresh Fresh Fresh Gasoline 28 ft2 Gasoline 28 ft2 Gasoline 28 ft2 Gasoline 28 ft2 Gasoline 28 ft2 32 36 28 50 52 418 X X 350 348 na na na na na 3.1 Dev 3 H alf 4.1 Dev3 H alf Fresh Gasoline 28 ft2 94 Fresh Gasoline 28 ft2 80 268* 278 na na 5.1 Dev3 H alf Salt Gasoline 28 ft2 Not Ext. na 6.1 Dev3 Full Salt Gasoline 28 ft2 67 240 7.1 RF6 Full Fresh Gasoline 28 ft2 40 500 na na na 7.2 RF6 Full Fresh Gasoline 28 ft2 41 525 na 8.1 AFFF Full Fresh Gasoline 28 ft2 25 444 na 9.1 RF6 10.1 RF6 10.2 RF6 11.1 RF6 11.2 RF6 Full Half Half Full Full Fresh Fresh Fresh Salt Salt Gasoline 28 ft2 Gasoline 28 ft2 Gasoline 28 ft2 Gasoline 28 ft2 Gasoline 28 ft2 39 46 44 45 41 403 331 348 372 367 na na na na na 12.1 RF6 12.2 RF6 13.1 AFFF 14.1 Dev3 15.1 RF6 Full Full Full Full Half Fresh Fresh Fresh Fresh Salt JP-5 28 ft2 JP-5 28 ft2 JP-5 28 ft2 JP-5 28 ft2 Gasoline 28 ft2 21 18 18 18 63 560 X X 389 245 na na na na na 16.1 Dev3 Double Fresh Gasoline 28 ft2 48 17.1 AFFF Full Fresh Gasoline 50 ft2 63 583 X na 363 17.2 AFFF 18.1 RF6 Full Full Fresh Gasoline 50 ft2 55 Fresh Gasoline 50 ft2 87 450 168 353 349 18.2 RF6 Full Fresh Gasoline 50 ft2 85 X 334 19.1 Dev3 Full X - Not Attempted Fresh Gasoline 50 ft2 Not Ext. na 340 na - Not Applicable *120 seconds o f foam application rather than 90, as fire not extinguished until 94 seconds. For evaluation purposes only, not MilSpec test protocol. 7 US00000841