Protection of Combustible Liquids Stored In Composite Intermediate Bulk Containers (IBCs) Research Project. Phase II Final Report.

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4 Protection of Combustible Liquids Stored In Composite Intermediate Bulk Containers (IBCs) Research Project Phase II Final Report Prepared for The Fire Protection Research Foundation Quincy, MA Prepared by Joseph L. Scheffey, P.E. Hughes Associates, Inc Commerce Drive, Suite 817 Baltimore, MD Ph. (410) FAX (410) and Martin J. Pabich, P.E. Underwriters Laboratories Inc. Northbrook, IL September 2007

5 EXECUTIVE SUMMARY Suppliers and manufacturers are continually faced with either receiving or storing chemicals in DOT-approved composite intermediate bulk containers (IBCs). NFPA 30 recognizes protection of composite IBCs (e.g., 31H1A units) when Listed and Labeled. This is based on previous Fire Protection Research Foundation (FPRF) testing. There has been limited implementation of this protection methodology, as evidenced by the lack of sales of Listed IBCs. Yet, anecdotally, many flammable and combustible liquid-filled composite IBCs are reportedly used in storage. Since Listed IBCs have the same general appearance as non-listed units, there was a perception that there was no difference in fire performance. Phase I of this current effort demonstrated that non-listed units may fail rapidly (in about three minutes) when protected by water sprinklers and subjected to a pan fire test. AFFF might be used to protect these units. The objective of the current Phase II tests was to provide replicate tests for two situations: 1. The Phase I, Test 1, using Listed IBCs instead of non-listed units used in Phase I the intent was to demonstrate any performance difference when 0.60 gpm/sq ft water sprinklers protected a 14-ft x 14-ft pan fire with mineral seal oil-filled IBCs. 2. An associated issue was the perceived difference in fire resistive performance between water-ladened and combustible liquid-filled IBCs. Differences at the bench-scale level have been observed. Associated with these two issues were performance differences between pan fire tests conducted in Phase I, and the large-scale fire performance test specified in Underwriters Laboratories Inc. (UL) Standard Fire Exposure Testing of Intermediate Bulk Containers for Flammable and Combustible Liquids, UL The water-ladened and combustible liquidfilled comparison testing was conducted using the UL 2368 large-scale method. A series of three fire tests were conducted at the Underwriters Laboratories Inc. s large-scale fire test facility during the time period April 10 12, All of the tests were conducted under a 30-ft. ceiling and utilized a water only sprinkler system. The system was designed with K (gpm/psi ½ ) pendent standard spray sprinklers having a 286 F standard response temperature rating. The nominal discharge density was 0.60 gpm/ft 2. All tests were conducted with eight Listed IBCs in a 2 high by 2 wide by 2 high (2 x 2 x 2) storage array. Test 1 involved the use of IBCs filled with mineral seal oil (254 F flash point Class IIIB combustible liquid) positioned in the center of a 14 x 14-ft. containment pan. The pan held leveling water and 110-gallons of mineral seal oil. The fire was ignited, and exposed the IBCs until sprinklers operated. A total of four (4) sprinklers operated. The pool fire was allowed to burn for approximately 20 minutes. The IBC had developed a distinguishable leak during the fire exposure. The second test was conducted in accordance with the UL 2368 large array test method using water-filled IBCs. The exposure fire was initiated with a heptane spill, followed by a heptane flow of 2 gpm through a pipe positioned in the center of the IBC storage array. A total of two (2) ii

6 sprinklers operated during the second fire test, after which relatively steady-state fire conditions were achieved. There was a persistent flue fire, and some flaming at the face of the array. The location of this face fire was variable during the test. The spill fire was allowed to burn for thirty minutes (30:00). The immediate posttest evaluation indicated that the IBC array exhibited melt down and burn through at the top of the lower units. The IBC appeared to hold the lading throughout the fire exposure and were set aside posttest to allow for further drainage of the applied fire protection water. After sitting for 24 hours the IBC were examined for leakage. The IBC had developed a weeping leakage of the laden material. The third test was a repeat of Test 2 using mineral oil-filled IBCs. A total of four (4) sprinklers operated. Again, steady-state conditions were observed after sprinkler actuation during the second fire test. The immediate posttest evaluation indicated that the IBC array exhibited melt down and burn through at the top of the lower units. The IBC appeared to hold the lading throughout the fire exposure and were set aside posttest to allow for further drainage of the applied fire protection water. After sitting for 24 hours the IBC were examined for leakage. The IBC had developed a weeping leakage of the laden material. Differences in failure times between non-listed (Phase I, Test 1) and Listed IBCs (Phase II, Test 1) in the pan fire test scenario cannot be exactly quantified. Listed IBCs in the pan fire test failed in less than 20 minutes. The failure results (collapse of bottles, discharge of the entire liquid contents) were similar to Phase I, Test 1, where non-listed IBCs were used. The 14-ft x 14-ft pan test is not equivalent to the UL large-scale fire test for assessing fire performance of composite IBCs. This is consistent with the findings of the original composite IBC scaling tests, where a smaller pan fire (5-ft x 5-ft platform within a 7-ft x 7-ft pan) was found to be a more severe challenge to IBCs compared to unconfined two- and three-dimensional spill fires. Tests 2 and 3 were a comparison of the effect of liquid ladening in the UL test method. Neither test passed the UL leakage criteria, which requires prevention of liquid loss below the IBC full liquid level. The Listed IBCs supplied for these tests apparently differed in construction details compared to the units which were originally tested. This may have contributed to the breaches observed in these tests. All other NFPA 30 performance criteria were essentially achieved. No significant differences in failure modes were observed. For this test scenario, no significant differences were observed in the performance between water ladened and oil filled containers. In Test 3 where mineral oil IBCs were tested, development of a large, growing pool fire was prevented. This is attributable to either a low amount of leaking oil (likely a function of the inherent fire resistivity of the unit tested) and/or the effectiveness of the water sprinkler system. The observation of the oil sheen in Test 3 suggests some suppression effectiveness of the sprinklers. However, the sprinklers were unable to suppress the Test 1 pan oil fire. Because of differences in test configurations (unconfined running fuel fire with leaking IBCs vs. confined pan with relatively thick fuel substrate plus leaking fuel from IBCs), quantitative conclusions on suppression effectiveness cannot be made. As observed in the original IBC tests, successful performance is likely a combination of IBC fire hardening (resistively to thermal threat) and water sprinkler cooling. iii

7 Protection of Combustible Liquids Stored in Composite Intermediate Bulk Containers (IBCs) Research Project Technical Panel Graham Atkinson, Health and Safety Laboratories, UK John Davenport, Consultant, Chair, Protection Task Group, NFPA 30 Committee Dwight Havens, Phoenix Fire Department Anthony Ordile, Loss Control Associates, Inc., Chair NFPA 30 Committee David Swenson, The Sherwin-Williams Company Christopher Wieczorek, FM Global Bob Benedetti, NFPA Staff Liaison Sponsors Dow Corning Corporation GE GAPS The Proctor and Gamble Company Schutz Container Systems, Inc. Silicones Environmental Health and Safety Council The Viking Corporation iv

8 ACKNOWLEDGEMENTS Thanks are extended to the project sponsors, including Dow Corning Corporation (Mike Snyder and Don Hicks), GE GAPS/Swiss Re (Pete Willse), The Proctor and Gamble Company (Christina Francis), Schutz Container Systems, Inc. (Brian Minnich), the Silicones Environmental Health and Safety Councile (represented by Joe Aleksa), and the Viking Corporation (Eldon Jackson). Thanks are also extended to the project technical panel, and the staff of the FPRF, particularly Kathleen Almand. The fire test team at Underwriters Laboratories Inc. provided excellent support. Finally, special thanks are provided to Dave Swenson of Sherwin-Williams for providing extra photographic and video documentation of the tests. v

9 TABLE OF CONTENTS Page EXECUTIVE SUMMARY... ii ACKNOWLEDGEMENTS... v 1.0 BACKGROUND SUMMARY OF RESULTS OF PHASE I TESTING PLANNING FOR PHASE II AND PHASE II OBJECTIVES MEASURES OF PERFORMANCE NFPA Pan Fire Test UL Potential Variations on Performance Criteria TEST FACILITY EQUIPMENT, MATERIALS, AND INSTRUMENTATION Intermediate Bulk Containers Stored Liquid Commodity Ceiling Sprinkler Systems Instrumentation Steel Containment Pan Heptane Delivery System TEST SETUP AND PROCEDURES Test Tests 2 and TEST RESULTS Test Test Test DISCUSSION Construction of Listed IBC Comparison of Fire Test Methodologies Impact of Liquid Ladening SUMMARY AND CONCLUSIONS REFERENCES APPENDIX A TESTS 1, 2 AND 3 RESULTS... A-1 vi

10 LIST OF TABLES Page Table 1 Summary of Test Phase I Results... 3 Table 2 Flash Point Results... 9 Table 3 Phase II Test Parameters and Results LIST OF FIGURES Figure 1 Test Facility... 7 Figure 2 Locations of Ceiling Thermocouples and Associated Sprinkler Designations Figure 3 Test 1 Set Up Figure 4 Test 2 and Test 3 Set Up Showing Heptane Fuel Supply Figure 5 Test 1 Plan View Figure 6 Test 2 and Test 3 Plan View Figure 7 Fuel Pipe for Tests 2 and Figure 8 Heptane Filled Bags for Ignition in Tests 2 and Figure 10 Test 1, Sprinkler Operation Times Figure 11 Test 1, Post-test Bulging of North Side of the Array Figure 12 Test 1, Bottle Collapse Figure 13 Test 2, Sprinkler Operation Times Figure 14 Test 2, Fire at Sprinkler Operation Figure 15 Test 2, Fire in Steady-state Conditions Figure 16 Test 2, Burning at Unit S1 Fill Cap, Exposing Underside of Unit S Figure 17 Test 2, Post-test Condition of Unit N1 Ullage Area Figure 18 Test 2, Post-test Holing of Unit N1 Top Fill Cap Figure 19 Test 2, Post-test Condition of Unit N1 Bottle Showing Stress Crack from Vertical Bar Branding Figure 20 Test 3, Sprinkler Operation Times Figure 21 Test 3, Fire after Sprinkler Operation Figure 22 Test 3, Fire at Northwest Corner of the Array Figure 23 Test 3, Leak in Unit W Figure 24 Test 3, Ullage Hole in Unit W Figure 25 Test 3, Leak from Unit W1 Doghouse Valve Cap Figure 26 Field Repair of IBC Doghouse for Tests 1 and Figure 27 Construction Details of the Listed IBC Supplied for Test Figure 28 Comparison of Large Array and Pan Fire Test Results, Class IB Fire Exposure, From Previous IBC Testing [5] Page vii

11 1.0 BACKGROUND Many industries utilize bulk packaging to store liquids, which are ultimately used for the production of commercial consumer products. Many of these liquids are classified as combustible liquids as defined by NFPA 30, Flammable and Combustible Liquids Code [1]. Due to market conditions and environmental regulations, there has been an increased interest worldwide in the use of composite intermediate bulk containers (IBCs) to store combustible liquids. Storage of bulk combustible liquid containers, including composite containers, is regulated in two distinct environments: during shipment or transport (Transportation Regulations); and in place in protected warehouses (Fire and Building Codes, such as NFPA 30). When bulk containers are transported, they fall under DOT/UN guidelines. These guidelines classify liquids as flammable if the flash point is 141 F or lower. Containers transporting flammable liquids must be tested for this application, e.g., for structural integrity such as resistance to dropping and puncturing. Packaging, such as composite IBCs, for materials having a flash point higher than this level, may not be required to be subjected to this testing. Many end users believe that since the container is approved for transportation purposes it is automatically acceptable for indoor storage of combustible liquids. In North America, when liquids are stored in protected warehouses using NPFA 30 criteria, Class I, II and III designations (associated with liquid flash and boiling points) are used, in part, to determine the protection criteria. In the mid 1990s, the Fire Protection Research Foundation (FPRF) carried out a major fire test program to determine how composite IBCs storing flammable and combustible liquids could be safely stored and protected; the focus was on how well the containers survived an exposure to a flammable liquid fire [2 6]. This research resulted in a formal container Listing process which, when combined with appropriate sprinkler protection, was intended to assure container integrity in the event of a warehouse fire [7]. No distinction is currently made in NFPA 30 in terms of flash point; all composite IBCs must be Listed containers where associated Class II and III liquid storage is to be considered protected. This requirement is not presently believed to exist in the fire regulations of other countries, however, increased regulatory focus on composite IBCs is taking place within the UK based on the results of UK Health & Safety Laboratory testing and several recent fires involving composite IBCs. Thus, there are differing construction requirements for composite IBCs in the transportation and warehouse (storage) environments in the United States, and in the warehouse storage environments among different countries. In March of 2005, industrial and commercial representatives, who manufacture and use combustible liquids, met with industry experts from the NFPA 30 Container and Portable Tank Committee to discuss possible approaches to resolve this issue. Due to their lower susceptibility to ignition, Class III combustible liquids stored in composite IBCs may inherently be less hazardous than lower flash point liquids (e.g., Class II liquids) from an ignitability standpoint. Examples of such liquids include cooking oil, motor oil, lubricants, paints and coatings, scents and flavorings, and other chemical intermediates. Currently there is little data to fully evaluate the hazard and associated protection requirements of composite IBCs containing high flash point liquids. 1

12 Since the original focus of the Foundation research project was on maintaining container integrity, rather than exploring ignition and fire development of the stored liquid, it was agreed that there might be an opportunity to bring the transportation and building storage requirements closer together. Additional testing of certain combustible liquids in non-listed/labeled IBCs, involving scenarios in which the composite IBC is breached during actual fire conditions, was of interest. Recent tests sponsored by Spacecraft Corporation, which involved IBCs with motor oil using a smaller ignition source without an initial spill (pool), demonstrated the role of automatic sprinkler protection in early stages of fire growth [8]. A logical extension of this work applied to the current situation with storage of high flash point liquids in certain IBCs, is to explore the performance of certain generic IBCs in a simulated storage situation with real-world ignition scenarios. The FPRF initiated a research program to investigate the appropriate fire protection requirements for the storage of Class IIIA and Class IIIB combustible liquids stored in composite IBCs. The program had two Phases. Phase I involved initial demonstration and scoping tests to explore the integrity of a common, unlisted IBC in a well-controlled pool fire exposing a pallet array. In reaction to the results of Phase I, Phase II tests investigated differences in test methodologies and liquid ladening in Listed composite IBCs. 2.0 SUMMARY OF RESULTS OF PHASE I TESTING Three palletized storage array tests were conducted August 22 25, 2006 at the Southwest Research Laboratory, San Antonio, TX. The results are documented in References 9 and 10. The storage array consisted of 275 gal (1041 liters) composite IBCs stacked in a 2 x 2 x 2 high array. The IBC, having a UN designation of UN31HA1Y, was a representative, non-listed container comprised of an inner HDPE bottle within a solid sheet steel outer enclosure. The only exposed area of the bottle was the top fill opening. The IBCs were filled with mineral oil having a 270 F flash point. The array was exposed to a pool fire exposure within a 14 ft x 14 ft x 30-in. high steel pan. The mineral oil pool was ignited in a corner of the test pan. The fire grew until it exposed the test array, and actuated sprinklers thirty feet above the floor. A summary of the test results are shown in Table 1. Damage as used in Table 1 refers to holing of the interior poly bottle. Test 1 was performed with 286 F standard response sprinklers discharging at 0.60 gpm/sq ft. Three minutes after ignition (self-sustained burning of the pool), sprinklers operated. At that time, flames involved about one half of the test pan. A total of four sprinklers operated. The pool fire growth was arrested and was ultimately suppressed. A fire within the flue space persisted throughout the test. There appeared to be some liquid discharging from containers, and fuel vapor contribution from the stored liquid. The test was terminated eleven minutes after ignition. Post-test inspection indicated that the four units closest to the ignition source were breached, and essentially all liquid had discharged from these containers. 2

13 Table 1 Summary of Test Phase I Results Parameter/Event Observation Test 1 Test 2 Test 3 Test 4 AS Density AS Temperature ( F) AS Rating SR SR SR SR Foam (%) N/A 3% 3% 3% Water Depth (in.) Fuel Depth (in.) Bottom of Pallet to Top of Fuel (in.) ~5 ~5 ~5 Time to Ignite (min:sec) 11:29 3:54 5:14 0:36 Ignition to First AS (min:sec) 3:08 1:43 2:34 3:00 AS Operated Ignition to Extinguish (min:sec) N/A* 3:32 N/A*** N/A Ignition to Terminate (min:sec) ~11:11 7:24 8:35 ~9:45 Damage N1 Y Y**** ND Y Damage N2 Y N** ND N Damage E1 Y N Y Y Damage E2 Y N ND N Damage S1 N N Y Y Damage S2 (Empty) Y N ND Y Damage W1 N N Y Y Damage W2 N N Y Y Max Air Temp ( F/Time) 450/3:05 257/1:43 446/2:33 433/2:54 Max Beam Temp ( F/Time) 175/3:12 121/2:39 209/2:34 200/6:11 AS Automatic sprinkler N/A Not applicable; ND Not determined; Y Yes; N No * Manual suppression; pool fire essentially suppressed; continued burning in flue/array ** Dimple *** AFFF pump failure ~1 min. after AS operation test aborted **** Container remained essentially full during and after the test In an effort to provide more rapid sprinkler operation and positive suppression effects, the parameters were changed for Test 2. AFFF, discharging through 155 F standard response sprinklers at 0.45 gpm/sq ft, was used. Six sprinklers actuated, and the fire was controlled and extinguished. One container had very small holes as a result of the fire exposure, but there was no substantial liquid oil loss from the container. No other containers were breached, and only slight deformation of the bottle wall was observed on two units closest to the ignition source. To determine if response time of the sprinklers was the key parameter for these positive results, Test 2 was repeated in Test 3 using 286 F sprinklers. There was a failure of the AFFF pump in Test 3; Test 4 was conducted as a repeat of Test 3. Only three sprinklers operated in this test, two of which were well away from the pan area. Because of insufficient AFFF discharge to the pool fire area, there was a persistent flue fire and breach of four of the oil-filled containers. Ambient wind may have affected this test. 3

14 It was concluded that: 1. The IBC tested can be generically described for purposes of referencing it in a fire safety code such as NFPA It appears that non-listed IBCs of the type tested, storing high flash point liquids, can be protected in accordance with NFPA Annex E criteria using AFFF provided: a. Low temperature rated sprinklers are used; and b. There is an allowance to permit minor breaching of the container, provided there is no significant liquid loss. This is consistent with the current NFPA 30 ANNEX E criteria F water sprinklers discharging at 0.60 gpm/sq ft. extinguished the confined pool fire, but not the well-established flue/pallet fire where discharging oil apparently contributed to the fire. It is unknown whether faster sprinkler operation (using 155/165 F sprinklers, or 286 F quick response sprinklers) would improve the water only suppression performance in this scenario. 4. Additional testing is required to: a. Validate the AFFF performance in a full scale, unbounded array; and b. More definitively identify and bound the sprinkler temperature rating characteristics for this scenario. 3.0 PLANNING FOR PHASE II AND PHASE II OBJECTIVES The project sponsors, project Technical Advisory Committee, and other interested parties, reviewed the Phase I data and provided comments related to a path forward: 1. Foam protection is the least viable method for retrofitting warehouses. 2. Ordinary temperature (155/165 F) sprinklers would be difficult to retrofit because: a. The inherent cost of physically replacing sprinklers; and b. The existing sprinkler design operating area may be insufficient to supply an area protected by ordinary temperature sprinklers (the use of high temperature sprinklers typically results in a lower required design area of application, compared to the use of ordinary temperature rated sprinklers). Hydraulically, the water demand in a retrofit situation may exceed the available supply. 3. Quick response (QR), 286 F temperature rated sprinklers are a viable retrofit option, which would likely result in a quicker operating time. This was shown to be important in Phase I. 4. There is a perception that the Listed IBC currently available on the market is essentially the same as the non-listed unit tested in Phase I, in terms of resistance to fire. Some believe the performance of the Listed unit would be similar to that observed in Phase I with non-listed units. 5. Except for limited scenarios in the original NFPRF IBC testing conducted in , this is the first public domain sprinkler testing of IBCs with hydrocarbon liquid lading. Most of the original IBC testing used water to simulate the 4

15 flammable/combustible liquid lading. Heptane was floated on top of the water ladening to provide a flammable liquid ignition source should the container breach at the ullage space. A report published by the UK Health and Safety Laboratory (HSL) [11] indicated potential differences in failure time when lading is varied in plastic containers. Plastics containing oils failed more rapidly when exposed in a small-scale burner fire test (non-sprinklered) compared to plastics with water lading. It was unclear whether this affects the current Listing procedure published by UL and recognized by NFPA 30. Based on this analysis, discussion, and input, the objectives of the Phase II tests were established to provide replicate tests for two situations: 1. Phase I, Test 1, using Listed IBCs instead of non-listed units used in Phase I the intent was to demonstrate any performance difference when 0.60 gpm/sq ft water sprinklers protected a 14-ft x 14-ft pan fire with mineral seal oil-filled IBCs. 2. The difference in fire resistive performance between water-ladened and combustible liquid-filled IBCs, to address the differences observed at the bench scale level [11]. Associated with these two issues were performance differences between pan fire tests conducted in Phase I, and the large-scale fire performance test specified in Underwriters Laboratories, Inc. (UL) Standard Fire Exposure Testing of Intermediate Bulk Containers for Flammable and Combustible Liquids, UL 2368[7]. The water-ladened and combustible liquid-filled comparison was conducted using the UL 2368 large-scale method. 4.0 MEASURES OF PERFORMANCE These tests are intended to provide data on the performance of IBCs under different fire threats and protection variables. The following performance parameters should be considered in evaluating the data. 4.1 NFPA 30 As described in NFPA 30 Annex E, the evaluation measures for determining the performance of a fire protection system on a flammable/combustible liquid storage fire are characterized as follows: 1. Prevent pressure buildup in containers or actual violent ruptures while this is not generally expected to occur in composite IBCs, there is data that suggest that units might pop and rupture when exposed to a small fire which locally heats the contents for a prolonged period [11]. 2. Prevent loss of liquid from a container in this case, holing might be permitted (e.g., in the ullage area) if liquid is not discharged from the container. 3. Limit the number of sprinklers operating the number of sprinklers operating should be significantly less than a reasonable design demand area for a typical warehouse. 5

16 4. Prevent ignition of adjacent target array or failure to control a fire in an adjacent target array this was not explicitly determined in these tests since a single pallet array was evaluated. 5. Limit temperature of structural or rack steel e.g., overhead steel temperature should not exceed 1000 F for more than a minute. 6. Control sustained ceiling gas temperatures related to measure 5, do not expose the building to excessive temperatures. 7. Prevent collapse of the stored containers or arrays. 4.2 Pan Fire Test The 14-ft x 14-ft pan fire test is intended to provide scoping data for IBC evaluation. No protection criteria per se, beyond the generalized criteria in Section 4.1, have been established. Limitations of the pan methodology were identified in previous IBC testing [5] and in the current Phase I tests. In particular, assessing sprinkler cooling/suppression is problematic. 4.3 UL 2368 UL will Classify a product which they have determined has demonstrated the ability to comply with requirements for a specific risk and conditions, and which may be recognized in regulatory codes such as NFPA 30. The product is tested as a component in a system (in this case, warehouse storage with specific sprinkler protection). There is a follow-up service. IBCs are currently Classified by UL when tested in accordance with UL Classification as used by UL meets the NFPA definition of Listed and Labeled. For this report, the NFPA definitions are used, and IBCs that have passed the UL test are termed Listed. For Classification purposes, UL 2368 has two basic criteria for both the reduced and largescale tests. There must be no evidence of leakage (liquid loss at a location below the full liquid level). Structural integrity of the IBCs must be maintained (no toppling of units, or leaning more than six inches or five degrees from the vertical). 4.4 Potential Variations on Performance Criteria Currently, the failure criterion for large, liquid-filled containers in NFPA 30, Annex E is loss of a substantial amount of liquid from a container other than the initiating container. In large container fire testing, it is generally assumed that a container breach has occurred, and this provides the initiating or threat fuel source. Ignition of this threat could be from a spark/flame or from an adjacent, radiating Class IV commodity fire. A revised philosophy for Class IIIB liquids may be appropriate, as described in the Phase I report [9]. Multiple container breaches (holing of the container) may be acceptable, provided: 1. A catastrophic or significant discharge is prevented; and/or 2. Adequate protection is provided, e.g., the fire is suppressed, the number of sprinklers operating is reasonable/acceptable, pallet stability is maintained (no personnel/firefighting hazard), and ceiling temperatures remain below critical values. 6

17 A key aspect to these potential revised criteria would be to define a catastrophic or significant discharge, and the appropriate level of protection. In this case, catastrophic failure is defined as a container which has lost all of its liquid contents. If a fire is nearly or totally suppressed, and all other criteria are met as far as protection, then multiple container breaching may be acceptable. 5.0 TEST FACILITY The fire tests were conducted in Underwriters Laboratories large-scale fire test facility located in Northbrook, Illinois. The large-scale fire test building used for this investigation houses four fire test areas that are used to develop data on the fire growth and fire suppression characteristics of commodities, as well as the fire suppression characteristics of automatic water sprinkler systems. A schematic of the test facility is shown in Figure 1. Figure 1 Test Facility The fire tests were conducted in a 120 by 120 by 54-ft. high room fitted with a 100 by 100-ft. adjustable height ceiling set to a height of 30 feet. The test room was equipped with an exhaust system through a regenerative, thermal oxidizing smoke abatement system. Make-up air was provided through four inlet ducts positioned along the walls of the test facility. The floor of the test facility was smooth, flat and surrounded with a grated drainage trench to insure adequate drainage from the test area. The water runoff from the suppression system drain was collected through an 180,000-gallon water treatment system. 7

18 6.0 EQUIPMENT, MATERIALS, AND INSTRUMENTATION 6.1 Intermediate Bulk Containers A single type of 275-gallon capacity composite intermediate bulk container (IBC) was utilized for this test work. The container was a Schutz Intermediate Bulk Container bearing the UN designation UN31HA1/Y/MMYY/D/USA/+AA2388/3356/1753/1041/8kg/100kPa. It was constructed using a blow molded high-density polyethylene bottle fit inside a ceramic fiber insulated steel container on a steel pallet frame. The ceramic fiber insulation was also termed ceramic paper by the vendor. These terms are used interchangeably in this report. These units were the UL Classified IBCs, identified as Model SX-UL. The bottle has an average thickness of 80 mils (0.08 in.). There is an approximate 2-in. diameter discharge valve and outlet at the bottom of one side of the IBC. This discharge outlet area is recessed within the outer steel container in an area commonly called a doghouse. The doghouse area was protected by a steel cover. The units measured 38 inches (doghouse side) by 46 inches by 40 inches high. An integral steel pallet was attached to the bottom, measuring 4.5 inches high. The pallet had a solid metal base at the bottom of the bottle enclosure. The top fill opening consisted of an approximate 6-inch diameter plastic screw-on cap having an integral 3-inch diameter snap-on cap. The caps, which reportedly provide some degree of fire resistance, were removed for these tests. This was the only area of the IBC where plastic was exposed. There were no view-hole openings in the outer steel enclosure. Post-test evaluation of the containers indicated that there was no overlap of fiber material at the corners or edges of these IBCs, which created small seam areas on the plastic bottle that were not protected by insulation. Also, in the units used in Tests 1 and 2, perforated cut-outs for the doghouse valve area face and bottom were missing. A field repair was made to correct this. Section 9.1 provides a more detailed discussion of the IBC construction. 6.2 Stored Liquid Commodity For the first and third fire test, the IBCs used in the test array were filled with a petroleum distillate commonly known as mineral seal oil. For the second fire test, the IBCs were filled with water and then 1 gallon of heptane was floated on the top of the water surface. A sample of the Mineral Seal Oil was subjected to the flash point test for a liquid in accordance with the Standard for Test For Comparative Flammability of Liquids, Part 6.3 in UL 340 (Fourth Edition) using the Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester (ASTM D 93-02a). The results of the testing are presented below in Table 2; the results are corrected for a barometric pressure of 747 mm Hg. The results indicate that the mineral seal oil is an IIIB combustible liquid per NFPA 30. 8

19 Sample Test No. Time, Minutes Table 2 Flash Point Results Observed Flash Point, F( C) 1 0 Started at 73 F Corrected Flash Point, F( C) F 251 F (121.7 C) 2 0 Started at 73 F F 256 F (124.4 C) Average of F(123.3 C) 6.3 Ceiling Sprinkler Systems The fire testing utilized a water sprinkler system designed with K (gpm/psi ½ ) pendent standard spray sprinklers provided by the Viking Corporation. They had a 286 F temperature rating with a standard response heat activated element. A nominal discharge density of 0.60 gpm/ft 2 was provided to protect the storage arrangements of Intermediate Bulk Containers. The test was conducted under a 30-ft ceiling with thirty-six (36) sprinklers installed on 10 by 10-ft. spacing. The distance from the sprinkler deflector to the ceiling was 12 inches. 6.4 Instrumentation The instrumentation used in the testing as shown in Figure 2 consisted of the following devices: 1. 1/16-in. diameter, Type K inconel-sheathed thermocouples were located below the ceiling adjacent to each sprinkler to record ceiling temperatures for fire tests conducted in the120 by 120-ft test cell. 2. A 1/16-in. diameter, Type K inconel-sheathed thermocouple was located 6-in. below the ceiling above the ignition location. 3. Five 1/16-in. diameter, Type K inconel-sheathed thermocouples were embedded in a 50.5-in. long steel beam attached to the bottom of the ceiling directly above the fire. 4. Bristol Babcock Model B pressure transducers in a (psi) range were used to measure the water pressure in the sprinkler system. 5. Fischer Porter model X3311SFD20 12-inch magnetic flow meter with a gallons per minute (gpm) range were used to measure the water flow rate. 6. Stopwatches and timing devices located within the data acquisition system were used to monitor and record significant events during the fire tests. 7. Video cameras were used to capture and record images of the fire test. 9

20 6.5 Steel Containment Pan A 14 x 14 x 1 ft. containment pan was used in Test 1 as shown in Figure 3. It was fabricated from 7-gauge steel with 2-in. drainage/leveling pipes and fittings positioned on the lower third of the sideboards on two sides. 6.6 Heptane Delivery System A system of flexible and hard 1-inch diameter pipe was used to deliver a 2 gpm flow of heptane from the test cell s storage and pumping facility (Figure 4). It supplied an upturned elbow positioned within the IBC storage array in Tests 2 and 3. Figure 2 Locations of Ceiling Thermocouples and Associated Sprinkler Designations 10

21 Figure 3 Test 1 Set Up Figure 4 Test 2 and Test 3 Set Up Showing Heptane Fuel Supply 11

22 7.0 TEST SETUP AND PROCEDURES All tests were performed using a 2-unit wide by 2-unit long by 2-unit high (2 x 2 x 2) storage array with 6-inch flue spaces. All units were positions so that the doghouses (discharge valve area) faced to the east in the array. A standard unit designation scheme was used: North (N), South (S), East (E), West (W), Lower (1), Upper (2). For example, the upper north unit was designated N2. The designations are shown in Figures 5 and 6. All units were filled to 98% full volume capacity (within one inch of the top of the container, which was within 2.5 inches of edge of top of the threaded fill opening). 7.1 Test 1 The steel pan was positioned on the floor in the center of the test cell under four sprinklers as shown in Figure 5. Concrete blocks were positioned in the test pan to support the IBC. Eight (8) oil filled SX UL IBCs were positioned in a 2 x 2 x 2 storage array, on concrete blocks in the test pan. A total 110 gallons of mineral seal oil was then pumped into the test pan. Water was added to the test pan and the liquid leveling fitting on the side of the test pan was adjusted until the liquid level was even with the tops of the concrete blocks. The center of an 8-in. diameter natural gas ring burner used for ignition was positioned 24-in. in both directions from the southeast corner of the test pan. The burner was operated at 10 psig. With the test commodity in place, the sprinkler system charged, and data acquisition systems operating, the ring burner was lit. When a self-sustaining fire was achieved, the ring burner was secured and removed. This was considered as test time 0:00. During the test, time, temperature, and flow information were gathered using high speed data acquisition equipment. Video images were captured and recorded. The test was scheduled to run for 20 minutes, recognizing that it was likely to be a more severe fire than the UL large-scale test method used in Tests 2 and Tests 2 and 3 Eight (8) SX-UL IBCs were positioned on the cement floor in a 2 x 2 x 2 array, with 6-in flue spaces, with the center located below four sprinklers as shown in Figure 6. In Test 2, the units were filled with water, with one gallon of heptane floated on the top as designated in UL2368. Mineral oil filled units were used in Test 3. A one-inch pipe used to supply the fuel for the three dimensional heptane fire was positioned within the storage array (Figure 7). The piping was arranged to provide the spill location approximately 6 inches above the base of the uppermost unit through an upturned elbow at the center intersection of the longitudinal and transverse flue space. The spill fire fuel loading utilized a 2-gallon spill of heptane over eight plastic bags each filled with 1gallon of heptane positioned in the longitudinal and transverse flue spaces (Figure 8). 12

23 The tests were conducted in accordance with UL With the test commodity in place, the sprinkler system was charged and data acquisition systems started, the fueling system was activated for one minute to discharge two gallons of fuel at the array. The fueling system was then secured and the heptane ignited using a torch (test time 0:00). At the operation of the first sprinkler, the fuel system was turned on to provide 2 gpm of heptane through the fuel delivery system. During the test, time, temperature, and flow information were gathered using high speed data acquisition equipment. Video images were captured and recorded. The test duration was 30 minutes. Figure 5 Test 1 Plan View 13

24 Figure 6 Test 2 and Test 3 Plan View 14

25 Figure 7 Fuel Pipe for Tests 2 and 3 Figure 8 Heptane Filled Bags for Ignition in Tests 2 and 3 15

26 8.0 TEST RESULTS A summary of the test results is presented in Table 3. Appendix A provides detailed graphical temperature, pressure and flow data. The following sections describe individual test results. The nomenclature for the times used in the descriptions uses the minute:second format. For example 1:30 indicates 1 minute, 30 seconds. Tests were conducted April 10 12, Test 1 The objective of Test 1 was to repeat Test 1 of Phase I, replacing a non-listed IBC with a Listed unit. Prior to the test, it was observed that there was no interior ceramic insulation protecting the doghouse (valve) area of the IBCs. The vendor representative indicated that there should be protection in this area. An ad hoc repair was made to each unit using available 0.6-inch thick Unifrax insulating material (see Section 9.1). The ring burner was ignited and the impinging fire ignited the mineral oil. The mineral oil started to ignite about one minute after exposure by the ring burner. At 1:40 after the initial ring burner ignition, the burner was removed since there was clearly self-sustained ignition in the Southeast corner of the test pan. As in the Phase I pan tests, this time is considered test time 0:00 for analysis purposes. The fire spread such that the Southeast triangular area was involved with fire at 0:17. By 0:40, there was a full fire involving the Southeast face of the IBC array, and flames extended feet above the pan. By 1:10, flames were feet above the pan and the pan area was approximately 50% involved (Figure 9). The first sprinkler over the Southeast corner operated at 1:22 (Figure 10). A flue fire was well established in the array. The pool surface fire started to be pushed to the Northeast corner of the pan. Between 2:42 and 2:56, the three other sprinklers over the test pan operated. Some knockdown of the flue and Northeast face fire were evident about one two minutes after these sprinklers operated. There was a persistent fire at the Northeast face of the array. In the 6 7 minute range, there appeared to be some fire at or under both the N2 and E2 IBCs. At 14:00, there was an obvious rise of the liquid level in the test pan, and the drain discharge pipe valve was opened. At 16:20, spill-over of the liquid was observed, and there was oil burning outside the pan. The floor fire was knocked down with an AFFF handline at 17:10, and again at 18:00. It appeared that the N2 and E2 units were spilling liquid. At 20:25, a foam handline was brought in and the pan fire totally extinguished. A total of four sprinklers operated during the test. The maximum steel temperature was 185ºF. 16

27 Table 3 Phase II Test Parameters and Results Fire Test Number Parameters Initiator 14 x 14-ft. Pan Fire UL2368 Spill Fire UL2368 Spill Fire Initiating Fuel Mineral Seal Oil Heptane Heptane Commodity Loading Oil filled Water Filled Oil Filled Commodity Type UL Classified IBC UL Classified IBC UL Classified IBC Nominal Ceiling Height, ft Centered Location Between 4 Between 4 Between 4 Sprinkler Orientation Pendent Pendent Pendent Temperature Rating, F Response Type Standard Standard Standard Deflector to Ceiling, in Sprinkler Spacing, ft x ft 10 by by by 10 Nominal Sprinkler Discharge Coefficient K, gpm/psi ½ Nominal Discharge Density, gpm/ft Results Length of Test, min:s 22:00 30:00 30:00 First Ceiling Sprinkler Operation, min:s 1:22 0:43 0:28 Last Ceiling Sprinkler Operation, min:s 2:56 0:45 3:10 Number of Operated Sprinklers Peak Gas Temperature at Ceiling Above Ignition, F Maximum 1 Minute Average Gas Temperature at Ceiling Above Ignition, F Maximum Steel Temperature, º F Maximum 1 Minute Average Steel Temperature Above Ignition, F Steel Temperature at End of Test, F 155 (before pan spillover, which occurred at 16:19) 129 (at conclusion) IBC Leakage Yes Yes Yes Damage 5 units catastrophic failure*(s1, N1, E1, W1, N2) 1 Leaking (E2) * Catastrophic failure is defined as total loss of ladening by the end of the test. ** Fail by UL test criteria of hole where liquid discharges. 1 w/slit leak (N1, fail**) 1 w/ullage holing (W1, borderline not known if any liquid leaked) 1 w/top cap burned off (S1, pass of UL criteria) 1 w/valve outlet leak plus doghouse leak (W2, fail) 1 w/face leak (W1 bottom joint, fail) 17

28 Figure 9 Test 1, Prior to Sprinkler Actuation The post-test inspection of the array indicated that five units (S1, N1, E1, and N2) had failed totally or catastrophically, that is, the bottles had collapsed, and all liquid contents had been discharged. Figure 11 shows the post-test array, with the North units bulging out. Failure was generally attributed to hot branding action where there was fire exposure (i.e., face fire or persistent blue fire). As the units expanded due to heat, the interior face insulation appeared to pull away from the bottle, and exposed plastic was branded from hot metal or directly holed from heat. The doghouse valve areas were generally in good condition, although there were signs on several units of softening and the potential onset of leaking. Figure 12 shows an example of the interior, a totally collapsed unit, with sprinkler water on top of the bottle. Additionally, the E2 unit was leaking at the bottom. This was the result of cracking along the edge of two sides exposed to the interior flue fire. 18

29 Figure 10 Test 1, Sprinkler Operation Times 19

30 Figure 11 Test 1, Post-test Bulging of North Side of the Array 20

31 Figure 12 Test 1, Bottle Collapse 8.2 Test 2 The objective of Test 2 was to conduct a confirming test of the UL 2368 methodology. The large-scale method was used, and the units were water-filled with one gallon of heptane floated on top. The Listed IBCs were used. As in Test 1, the doghouse was not completely protected, and the ad hoc repair was performed to protect the valve area. The fire was ignited, and two sprinklers operated at 0:43 and 0:45 respectively as shown in Figure 13. This activation time was consistent with prior tests; generally, a minimum of four sprinklers operate. At the time of sprinkler operation, the flame height was about 15 feet above the array (Figure 14). By 2:00, after the 2 gpm heptane fuel flow had been initiated, the flame from the flue extended to the ceiling. At 5:00, the fire was in essentially steady-state condition, with the flue flame extending nearly to the ceiling, and fire burning under the S2 pallet (Figure 15). In the 7 10 minute range, the floor fire was pushed to the North side. Since there was no sprinkler operating at the Northwest corner of the array, an array face fire became established in this area. It did not appear that any significant water was penetrating the flue fire plume. By 19 minutes, there was some bulging of the N1 unit. At 23 minutes, there was some burning evident between the S1 and S2 units. The fire continued to burn in a relatively steadystate manner (Figure 16). The floor fire shifted around at various times, but was most persistent at the North face. The test was terminated at 30:00 by securing the fuel flow, and totally extinguished at 30:34. The maximum steel temperature was 194ºF. 21

32 Figure 13 Test 2, Sprinkler Operation Times 22

33 Figure 14 Test 2, Fire at Sprinkler Operation Figure 15 Test 2, Fire in Steady-state Conditions 23

34 Figure 16 Test 2, Burning at Unit S1 Fill Cap, Exposing Underside of Unit S2 There was some minor bulging of units N1 and N2 at the conclusion of the test. The bulging of IBCs was not as great as in Test 1. The array itself was structurally sound, with no sign of potential collapse of the array. A post-test inspection of the liquid contents indicated that all units were essentially full. There was no leakage or holes in five of the units. The S1 unit had the fill cap burned off. Since no liquid leaked or discharged from the unit, it would be considered as passing the UL test. The top of unit N1 had some melting evident (bottle depressed, Figure 17) and the top fill cap had a burn hole (Figure 18). Approximately three inches of liquid had been lost at the conclusion of the test. There was leakage evident from the West (flue) side, which resulted from branding from an exterior vertical support bar (Figure 19). This created a slit leak at this pressure point. The unit would be considered to have failed the UL test. A third unit was considered borderline in terms of leakage/failure. Unit W1 had some holing in the ullage area and there was a crack at the Southwest (flue) top corner. It was not clear whether any liquid had leaked from the container. No significant loss of liquid was observed. The top units in the array were essentially undamaged. 24

35 Figure 17 Test 2, Post-test Condition of Unit N1 Ullage Area Figure 18 Test 2, Post-test Holing of Unit N1 Top Fill Cap 25

36 Figure 19 Test 2, Post-test Condition of Unit N1 Bottle Showing Stress Crack from Vertical Bar Branding 26

37 8.3 Test 3 Test 3 was a repeat of Test 2. The variable changed was the IBC contents. Mineral oil was the liquid loading in Test 3. Because of the questions raised about the lack of doghouse protection in the delivered IBCs, the vendor representative had a new shipment of Listed IBCs delivered for Test 3. These units had ceramic fiber installed in the doghouse valve area. It was part of the continuous sheet from the side, and from the sheet on the bottom of the container. Sprinkler operation in this test was quicker than in Test 2 (Figure 20). The first sprinkler operated at 0:28. All four sprinklers centered over the test array operated, with three operating in the 0:28 0:38 time range. The final sprinkler operated at 3:10. At 1:00, flames from the flue extended to the ceiling. At 1:40, some die down of the floor fire was observed. At 5:00, all fire was contained within the array (Figure 21), but this was variable during the test. At 6:30 9:00, there was a floor fire at the North face of the array, in addition to the persistent flue fire. At 13:00, some observers believed they saw flaming oil in a line on the floor. At 13:00 14:30, a fairly persistent fire became established on the Northwest and West sides of the array (Figure 22). This floor fire had a tendency to move about the array. The heptane fuel flow was secured at 30:00, and at 31:15 the fire was totally extinguished. The maximum steel temperature was 191ºF. There was some question whether a significant amount of oil leaked from any container and became involved with fire. One observer reported seeing an oil sheen on the floor at 9 10 minutes after ignition. Floor fire rivulets were observed in the minute time frame, suggesting potential mineral oil involvement. However, the shifting nature of the floor fire was also a characteristic of the heptane running fuel fire observed in the original IBC tests [4,5]. No significant bulging was observed in the array, as was observed in Test 1, and to a lesser extent, Test 2. It should be noted that the total weight of each of these units was less than in Test 2, because of the lower density of the mineral oil. The array was structurally sound. The top units were essentially undamaged from the fire exposure. Two bottom units were observed post-test to have leaks (failed UL criteria). Unit W2 had a 1-in. long oblong hole in the ullage space interface with the liquid. Some liquid may have leaked out from this hole. The doghouse was severely damaged, but no hole was immediately obvious. Sixty minutes after the test, about half of the contents were still in the unit. Examination after removal of the outer steel shell revealed a hole at the bottom crease of the bottle, near the corner of the container (Figure 23). This was where two sections of the inner insulation met in a butt-type arrangement and where a vertical steel outer cage bar pressed against the inner bottle. 27

38 Figure 20 Test 3, Sprinkler Operation Times 28

39 Figure 21 Test 3, Fire after Sprinkler Operation Figure 22 Test 3, Fire at Northwest Corner of the Array 29

40 Figure 23 Test 3, Leak in Unit W2 Unit W1 also had a leak. Most of the liquid appeared to remain within the unit. There was a large (about 2 in x 4 in) hole in the top ullage area (Figure 24), and the top of the bottle was slumped down in this area. This was the corner of the unit exposed to the flue fire. The top cap was severely melted. It is not clear if any liquid leaked out of this area; some liquid leakage is likely to have occurred. There was also a leak out of the cap attached to the ball valve in the doghouse discharge outlet (Figure 25). The N1 unit had some damage, with the top cap melted out. There was no apparent leakage from this unit. Any liquid leaking from units in this test was either insufficient to create a large pool fire, or was cooled sufficiently by the overhead water to prevent any significant fire involvement. 30

41 Figure 24 Test 3, Ullage Hole in Unit W1 Figure 25 Test 3, Leak from Unit W1 Doghouse Valve Cap 31

42 9.0 DISCUSSION 9.1 Construction of Listed IBC There were several issues with the construction of the Listed IBCs supplied for the project. As noted in Section 4.3, the units supplied were Classified by UL. They would meet the NFPA 30 definition of Listed. The units supplied and used in Tests 1 and 2 had ceramic paper insulation between the outer steel and inner bottle. The paper is evidently supplied in standardized sheet sections matching the dimensions of the sides, top, and bottom of the IBC. Each insulation section had perforation cut-outs for the top fill hole, and the face and bottom of the doghouse area. The top fill hole ceramic is normally cut out, and the unit shipped with the fill cap unprotected. There is a plastic dust cover, which was not installed during these tests. The ceramic at the face and under the doghouse is intended to stay in place. The face piece is cut out when the unit is delivered from storage to a user for field use. All units in Tests 1 and 2 were supplied with the valve area face and bottom ceramic already cut out. A field repair was made for Test 1 and 2 units as described in Section 8.1. Care was taken to protect both the valve area and bottom joint interfaces, particularly the edge between the side and bottom of the doghouse area (Figure 26). Given the lack of doghouse protection, a new shipment of Listed IBCs was provided for Test 3. These units did include the ceramic around the doghouse area. Closer inspection of the units revealed other apparent differences between the delivered units and construction details reportedly included in the manufacturer s UL Classification report. The ceramic blanket in the delivered units (Figure 27) consisted of three pieces: a piece laid on the bottom; a single continuous piece which was fitted around the sides of the unit, with the seam butted-together (no overlap); and a piece laid on the top. Figure 27 shows the bottom doghouse insulation section pulled back. The intersection between top, bottom, and side pieces were essentially butt seams, with no overlap of material. In the original UL Classification design, additional 20-in. wide strips of ceramic blanket were reportedly placed at the corner joints, extending down into the bottom of the unit. This provided an overlap of insulation paper at joints. The limitation of the lack of overlapped paper at the joints and bottom protection of the doghouse was evident in Tests 2 and 3. Failure points occurred where the blanket had separated at a vertical joint (Test 2, Unit N1) and at the bottom joint (Test 3, Unit W3, Figure 23). There also was apparent weakness where the ceramic sheets met at the bottom of the doghouse; ceramic paper in the units for Test 3 had a gap in front of the doghouse valve. This apparently contributed to the valve leak in Test 3 (Unit W1, Figure 25). The ad hoc insulation repair provided better protection (Figure 26). 32

43 Figure 26 Field Repair of IBC Doghouse for Tests 1 and 2 Figure 27 Construction Details of the Listed IBC Supplied for Test 3 33