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Jul 31, 2013 - Smoldering ignition resistance of fire barrier clad upholstered furniture ...... 30 California Technical
RESEARCH REPORT

UPHOLSTERED FURNITURE FLAMMABILITY Thomas Fabian, Ph.D. Fire Hazards Manager, Corporate Research

DISCLAIMER In no event shall UL be responsible to anyone for whatever use or nonuse is made of the information contained in this Report and in no event shall UL, its employees, or its agents incur any obligation or liability for damages including, but not limited to, consequential damage arising out of or in connection with the use or inability to use the information contained in this Report. Information conveyed by this Report applies only to the specimens actually involved in these tests. UL has not established a factory Follow-Up Service Program to determine the conformance of subsequently produced material, nor has any provision been made to apply any registered mark of UL to such material. The issuance of this Report in no way implies Listing, Classification or Recognition by UL and does not authorize the use of UL Listing, Classification or Recognition Marks or other reference to UL on or in connection with the product or system.

Issue date: July 31, 2013

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EXECUTIVE SUMMARY Upholstered furniture was identified as a source of dangerous fire potential forty years ago in the 1973 report “America Burning” written by the National Commission on Fire Prevention and Control.1 In the report smoking was identified as the predominant source of upholstered furniture fires. Since then considerable attention has been given to reduce fires and associated losses stemming from smoking related ignition sources including development of voluntary standards and mandatory regulations, campaigns to curb smoking, and regulations and campaigns to increase the presence of smoke alarms in households. Between 1980 and 2009, residential structure fires originating with upholstered furniture declined from 36,900 to 5,600.2 While the number of upholstered furniture fires has been significantly reduced since 1980, they remain persistent and deadly. During the 2006 to 2010 time period these fires resulted in annual averages of 480 civilian deaths, 840 injuries, and more than $427 million in direct property damage.3 The National Fire Protection Association (NFPA) reported that “fires beginning with upholstered furniture accounted for 2% of reported home fires but one of every five (19%) home fire deaths.” Considerably less attention has been given to fires beginning from open flame ignition of furniture. Small open flames such as candles, matches or lighters represent a different exposure threat than smoldering induced by smoking materials or heating equipment. Upholstered furniture fires started by small open flames are more likely to spread to the surrounding room and residential structure than fires started by smoking materials. During a home fire, upholstered furniture can become a significant fuel source. When exposed to an open flame, this furniture can substantially contribute to a room’s time to flashover. Limiting the fire growth from an upholstered furniture item can improve occupant safety and likelihood of safely escaping. UL, a leader in fire safety for over a century, initiated a self-funded exploration study in 2008 to explore whether or not commercially available products such as flame retardant treated foams and fire barriers (interliners) can retard and/or reduce the fire growth rate of upholstered furniture exposed to small open flames. This study was an extension to what was learned for mattresses (another significant source of fuel in a home fire) following the 2006 Consumer Product Safety Commission’s Standard for the Flammability (Open Flame) for Mattress Sets 4. Eleven commercially available barrier materials constituting different chemistries and physical structures (including flat weaves, knits and high lofts); two comparable density polyurethane foam materials, a non-flame retardant foam commonly used in upholstered furniture and a 1

“America Burning”, The Report of the National Commission on Fire Prevention and Control, US Fire Administration, United States (May 4, 1973). 2 Ahrens, M. “Home Fire that Began with Upholstered Furniture”, National Fire Protection Association, United States (2011). 3 Ahrens, M. “Home Structure Fires”, National Fire Protection Association, United States (2012). 4 16 CFR Part 1633 Standard for the Flammability (Open Flame) for Mattress Sets, U.S. Consumer Public Safety Commission, United States. (March 15, 2006). This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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California Technical Bulletin (TB) 117 compliant fire-retardant treated foam; and the most popular cover fabric from the largest upholstered furniture cover fabric supplier in the USA were included in the investigation. The investigation covered three scales of combustibility: (1) material-level experiments, (2) mock-up experiments, and (3) full-size furniture experiments. The combustibility behavior of the individual sample materials and combinations of materials (i.e. foam/barrier liner/cover fabric) under well-ventilated, early stage flaming fire conditions was characterized using a cone calorimeter. In the mock-up experiments, cushions of the foam and barrier liner combinations evaluated in the material-level experiment phase were arranged to replicate an interior corner such as that formed by the seat, back, and arm of a chair/sofa. The mock-up arrangements were ignited at the interior intersection of the three cushions using a match-flame equivalent gas burner. Heat release rate and mass loss rate were measured under an open calorimeter. Combustibility of full-size chairs and sofas made from four of the foam and barrier liner combinations was compared. Furniture pieces were ignited at a seat-back-arm interior corner, center of the seat-back cushions, and the back leg area using the same match-flame equivalent gas burner as for the mock-up assemblies. Heat release rate and mass loss rate were measured under a product calorimeter. While this investigation was by no means all encompassing, particularly with regards to the flame retardant treated foam and the commercial applicability of the tested fire barrier and foam materials, data from the cone calorimeter material-level, intermediate calorimeter mock-up, and full-scale furniture testing indicate the following: 

The three investigated general fire mitigation approaches for upholstered furniture (substitution of foam without fire retardants with flame retardant treated foam, substitution of polyester wrap with high-loft fire barrier, and inclusion of a flat fire barrier between the cover fabric and polyester wrap) demonstrated some degree of reduction in ignitability and/or flammability.



A layer of smooth bond polyester wrap (used to “soften” cushion edges) was sufficient to make the investigated fire-retardant treated foam indistinguishable from the untreated foam.



Fire barrier technology, i.e. material chemistry and physical form, played a significant role on ignitability and combustibility; however, all of the sample combinations incorporating the fire barriers exhibited greater fire resistance than the polyester wrapped polyurethane foam cushion with or without flame retardant.



Fire barriers were more effective retarding fire growth than the flame retardant treated foam meeting the minimum performance requirements specified in TB 117. It should be noted that TB 117 only prescribes a minimum performance level and that other compliant foam products utilizing different flame retardant chemistries and/or concentrations may yield more significant results.



Inclusion of an investigated fire barrier significantly retarded self-sustained flaming and fire growth rate in upholstered chairs. This slower growth rate could delay or even prevent room flashover thereby potentially reducing occupant deaths and injuries and property damage.



Poor seam construction can compromise the effectiveness of fire barriers. This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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ADDITIONAL INFORMATION Supplemental to the research presented herein, a series of living room fires and house fires were conducted to better illustrate the impact upholstered furniture materials play on fire growth and subsequent occupant tenability and survivability. These experiments were limited to a few combinations of materials. An overview can be found at www.ul.com. RECOMMENDATIONS FOR FUTURE RESEARCH Based upon the results of this Project, the following were identified as areas that would benefit from further research:  Assessment of new fire barriers not available at the time of this investigation  Broader study of flame retardant treated foams with regards to flame retardant chemistry and concentration effects on upholstered furniture flammability  Impact of filling materials other than polyurethane foam on upholstered furniture flammability  Combinations of flame retardant treated foam, other filling materials, and barriers  Smoldering ignition resistance of fire barrier clad upholstered furniture  Further refinement of small-scale predictive flammability test methods  Assessment of furniture geometry impact on upholstered furniture flammability  Impact of aging and use on the flammability of upholstered furniture constructed with fire barriers and/or flame retardant-treated foams  Impact of the slower fire growth rate in upholstered furniture on the time to room flashover  Impact of the slower fire growth rate in upholstered furniture on occupant tenability and survivability

This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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TABLE OF CONTENTS EXECUTIVE SUMMARY ............................................................................................................ ii Additional information .............................................................................................................. iv Recommendations for Future Research ..................................................................................... iv LIST OF FIGURES ...................................................................................................................... vii LIST OF TABLES ........................................................................................................................ xii INTRODUCTION .......................................................................................................................... 1 FIRES ORIGINATING FROM SMOLDERING IGNITION SOURCES................................. 2 Fires Originating from Smoking Materials (small smoldering ignition source) ..................... 2 Fires Originating from Heating Equipment (large smoldering ignition source) ..................... 6 Fires Originating from Electrical Distribution and Light Sources .......................................... 6 FIRES ORIGINATING FROM OPEN FLAMES...................................................................... 6 PROJECT OBJECTIVE AND TECHNICAL PLAN................................................................... 11 OBJECTIVES ........................................................................................................................... 11 LIMITATIONS IN SCOPE ...................................................................................................... 11 TECHNICAL PLAN ................................................................................................................ 11 TASK 1 – SELECT AND PROCURE SAMPLE MATERIALS ................................................. 13 TASK 2 – CHARACTERIZATION OF SAMPLE MATERIALS .............................................. 17 EXPERIMENTAL .................................................................................................................... 17 Density .................................................................................................................................. 17 Thickness .............................................................................................................................. 17 Chemistry (FTIR) .................................................................................................................. 17 Elemental Analysis (ICP-MS) .............................................................................................. 17 Quantitative Elemental Analysis (Boron, Bromine and Chlorine) ....................................... 18 Pyrolysis-GC/MS (Py-GC/MS) ............................................................................................ 19 Thermal Degradation (TGA) ................................................................................................ 20 SEM-EDS ............................................................................................................................. 20 Potential Heat ........................................................................................................................ 20 Combustibility....................................................................................................................... 20 RESULTS ................................................................................................................................. 21 Density .................................................................................................................................. 21 Thickness .............................................................................................................................. 22 Chemistry (FTIR) .................................................................................................................. 22 Elemental Analysis (ICP-MS) .............................................................................................. 28 Quantitative Elemental Analysis (Boron, Bromine and Chlorine) ....................................... 30 Pyrolysis-GC/MS (Py-GC/MS) ............................................................................................ 30 Thermal Degradation (TGA) ................................................................................................ 31 SEM-EDS ............................................................................................................................. 41 Potential Heat ........................................................................................................................ 44 Combustibility....................................................................................................................... 44 SUMMARY .............................................................................................................................. 46 TASK 3 – MATERIAL COMBINATION COMBUSTIBILITY EXPERIMENTS .................... 48 SAMPLES ................................................................................................................................ 48 EXPERIMENTAL .................................................................................................................... 50 This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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RESULTS ................................................................................................................................. 51 Foam Thickness .................................................................................................................... 54 Polyester Wrap ...................................................................................................................... 54 Flame retardant Treated Foam .............................................................................................. 56 High-Loft Barriers ................................................................................................................ 58 Flat Barriers .......................................................................................................................... 61 ANALYSIS AND DISCUSSION ............................................................................................ 64 Influence of Cover Fabric ..................................................................................................... 64 Ignitability ............................................................................................................................. 66 Combustion Duration and Intensity ...................................................................................... 67 Correlation between Combustibility Results ........................................................................ 70 SUMMARY .............................................................................................................................. 72 TASK 4 – MOCK-UP ASSEMBLY COMBUSTIBILITY EXPERIMENTS ............................. 73 SAMPLES ................................................................................................................................ 73 EXPERIMENTAL .................................................................................................................... 74 RESULTS ................................................................................................................................. 76 Influence of Polyester Wrap ................................................................................................. 84 Influence of Flame retardant Treated Foam .......................................................................... 86 Influence of High-Loft Barriers ............................................................................................ 87 Influence of Flat Barriers ...................................................................................................... 90 ANALYSIS ............................................................................................................................... 94 Ignitability and Self-Sustained Combustion ......................................................................... 94 Combustion Duration and Intensity ...................................................................................... 95 SUMMARY .............................................................................................................................. 96 TASK 5 – FULL-SCALE FURNITURE COMBUSTIBILITY EXPERIMENTS ...................... 98 SAMPLES ................................................................................................................................ 98 EXPERIMENTAL .................................................................................................................. 101 RESULTS ............................................................................................................................... 101 ANALYSIS ............................................................................................................................. 109 Influence of Ignition Location ............................................................................................ 109 Influence of Furniture Component Materials ..................................................................... 113 Comparison of Full-scale Furniture Experiments to Mock-Up Assembly Experiments .... 115 SUMMARY ............................................................................................................................ 118 FINDINGS .................................................................................................................................. 120 IMPLICATIONS FOR POLICY AND PRACTICE .................................................................. 125 IMPLICATIONS FOR FUTURE RESEARCH ......................................................................... 125 FUNDING DISCLOSURE ......................................................................................................... 126 APPENDIX A: MOCK-UP ASSEMBLY TEST FRAME ......................................................... 127 APPENDIX B: FULL-SCALE FURNITURE HEAT RELEASE RATE AND MASS LOSS PLOTS ........................................................................................................................................ 128

This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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LIST OF FIGURES Figure 1: CPSC Cigarette Ignition Resistance Test (reprinted from 16 CFR Part 1634) ............... 3 Figure 2: Polyester microsuede cover fabric (C) .......................................................................... 14 Figure 3: Polyester wrap (W) ........................................................................................................ 14 Figure 4: Fire barrier 1 (FB1) ....................................................................................................... 14 Figure 5: Fire Barrier 2 (FB2) ....................................................................................................... 14 Figure 6: Fire Barrier 3 (FB3) ....................................................................................................... 14 Figure 7: Fire Barrier 4 (FB4) ....................................................................................................... 14 Figure 8: Fire Barrier 5 (FB5) ....................................................................................................... 15 Figure 9: Fire Barrier 6 (FB6) ....................................................................................................... 15 Figure 10: Fire Barrier 7 (FB7) ..................................................................................................... 15 Figure 11: Fire Barrier 8 (FB8) ..................................................................................................... 15 Figure 12: Fire Barrier 9 (FB9) ..................................................................................................... 15 Figure 13: Fire Barrier 10 (FB10) ................................................................................................. 15 Figure 14: Fire Barrier 11 (FB11) ................................................................................................. 16 Figure 15: ASTM E1354 Cone calorimeter sample holder .......................................................... 21 Figure 16: FTIR spectra for cover fabric C and polyester wrap W. ............................................. 23 Figure 17: FTIR spectra for PU and frPU foams. ......................................................................... 24 Figure 18: FTIR spectra for para-aramid flat fire barriers FB1 and FB2. .................................... 24 Figure 19: FTIR spectra for flat fire barrier FB3. ......................................................................... 25 Figure 20: FTIR spectra for elastic knit flat fire barriers FB4, FB5, and FB6. ............................ 25 Figure 21: FTIR spectra for cotton high-loft fire barrier FB7 and rayon high-loft fire barrier FB9. ..................................................................................................................................... 26 Figure 22: FTIR spectra for two-layer (cotton/rayon) high-loft fire barrier FB8. ........................ 26 Figure 23: FTIR spectra for three-layer (cotton/rayon/rayon) high-loft fire barrier FB10. .......... 27 Figure 24: FTIR spectra for high-loft fire barrier FB11. .............................................................. 27 Figure 25: FTIR spectra for decking D. ........................................................................................ 28 Figure 26: TGA results for cover fabric C. ................................................................................... 32 Figure 27: TGA results for polyurethane foam PU. ..................................................................... 33 Figure 28: TGA results for flame retardant treated polyurethane foam frPU. .............................. 33 Figure 29: TGA results for polyester wrap W. ............................................................................. 34 Figure 30: TGA results for para-aramid flat fire barrier FB1. ...................................................... 34 Figure 31: TGA results for para-aramid flat fire barrier FB2. ...................................................... 35 Figure 32: TGA results for flat fire barrier FB3. .......................................................................... 35 Figure 33: TGA results for elastic knit flat fire barrier FB4. ........................................................ 36 Figure 34: TGA results for elastic knit flat fire barrier FB5. ........................................................ 36 Figure 35: TGA results for elastic knit flat fire barrier FB6. ........................................................ 37 Figure 36: TGA results for cotton high-loft fire barrier FB7........................................................ 37 Figure 37: TGA results for rayon layer of two-layer high-loft fire barrier FB8. .......................... 38 Figure 38: TGA results for cotton layer of two-layer high-loft fire barrier FB8. ......................... 38 Figure 39: TGA results for rayon high-loft fire barrier FB9. ....................................................... 39 Figure 40: TGA results for rayon layer of three-layer high-loft fire barrier FB10. ...................... 39 Figure 41: TGA results for cotton layer of three-layer high-loft fire barrier FB10. ..................... 40 Figure 42: TGA results for high-loft fire barrier FB11................................................................. 40 Figure 43: TGA results for decking D. ......................................................................................... 41 This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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Figure 44: Cone calorimeter measured heat release rate profiles for polyurethane (PU) foam. .. 45 Figure 45: Cone calorimeter measured heat release rate profiles for flame retardant treated polyurethane (frPU) foam. .......................................................................................... 45 Figure 46: Cone calorimeter cover fabric cut layout (left) and sample (right). Dashed lines are fold lines; cross-hatched regions are overlapping portions on the sample bottom. .... 50 Figure 47: Time to ignition (blue) and flame duration (red) for cone calorimeter samples. Error bars are SD. ................................................................................................................. 52 Figure 48: Peak and 180 second average heat release rates for cone calorimeter samples. Error bars are SD. ................................................................................................................. 53 Figure 49: Effective heat of combustion for cone calorimeter samples. Error bars are SD. ........ 53 Figure 50: Polyurethane foam thickness effect on cone calorimeter measured combustibility. .. 54 Figure 51: Polyester wrap effect on combustibility of 25 mm thick foam cone calorimeter samples. ....................................................................................................................... 55 Figure 52: Polyester wrap effect on combustibility of 51 mm thick foam cone calorimeter samples. ....................................................................................................................... 55 Figure 53: Polyester wrap effect on combustibility of 51 mm thick fire-retardant treated foam cone calorimeter samples. ........................................................................................... 56 Figure 54: Comparison of cone calorimeter measured combustibility for 51 mm thick polyurethane foam and fire-retardant treated foam samples....................................... 57 Figure 55: Comparison of cone calorimeter measured combustibility for polyester wrap covered 51 mm thick polyurethane foam and fire-retardant treated foam samples. ................ 57 Figure 56: Comparison of cone calorimeter measured combustibility for polyester wrap covered polyurethane foam and high-loft fire barrier 7 covered foam samples. ...................... 58 Figure 57: Comparison of cone calorimeter measured combustibility for polyester wrap covered polyurethane foam and high-loft fire barrier 8 covered foam samples. ...................... 59 Figure 58: Comparison of cone calorimeter measured combustibility for polyester wrap covered polyurethane foam and high-loft fire barrier 9 covered foam samples. ...................... 59 Figure 59: Comparison of cone calorimeter measured combustibility for polyester wrap covered polyurethane foam and high-loft fire barrier 10 covered foam samples. .................... 60 Figure 60: Comparison of cone calorimeter measured combustibility for polyester wrap covered polyurethane foam and high-loft fire barrier 11 covered foam samples. .................... 60 Figure 61: Comparison of cone calorimeter measured combustibility for polyester wrap covered polyurethane foam samples with and without flat fire barrier 1. ................................ 61 Figure 62: Comparison of cone calorimeter measured combustibility for polyester wrap covered polyurethane foam samples with and without flat fire barrier 2. ................................ 62 Figure 63: Comparison of cone calorimeter measured combustibility for polyester wrap covered polyurethane foam samples with and without flat fire barrier 3. ................................ 62 Figure 64: Comparison of cone calorimeter measured combustibility for polyester wrap covered foam samples with and without flat fire barrier 4. Note reignition of two barrier clad samples. ....................................................................................................................... 63 Figure 65: Comparison of cone calorimeter measured combustibility for polyester wrap covered polyurethane foam samples with and without flat fire barrier 5. ................................ 63 Figure 66: Comparison of cone calorimeter measured combustibility for polyester wrap covered polyurethane foam samples with and without flat fire barrier 6. ................................ 64 Figure 67: Comparison of cone calorimeter measured combustibility for PU foam samples with and without cover fabric. ............................................................................................ 65 This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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Figure 68: Comparison of cone calorimeter measured combustibility for frPU foam samples with and without cover fabric. ............................................................................................ 66 Figure 69: Inverse relationship between flame duration and peak heat release rate. Error bars are SD. .............................................................................................................................. 69 Figure 70: Inverse relationship between peak heat release rate and ignition. Error bars are SD. 70 Figure 71: First order correlation between effective heat of combustion and weight loss for cone calorimeter samples. Error bars are SD. ..................................................................... 71 Figure 72: Zero-intercept, third order correlation between effective heat of combustion and weight loss for cone calorimeter samples. Error bars are SD. .................................... 71 Figure 73: Mock-up assembly cushion arrangement example on test frame................................ 73 Figure 74: Mock-up experiment set-up......................................................................................... 75 Figure 75: Mock-up assembly experiment sample ignition exposure sequence........................... 76 Figure 76: Examples of post-experiment mock-up assemblies exhibiting (L to R): rapid selfextinguishment, delayed self-extinguishment, and consumed. ................................... 77 Figure 77: Time lapse photographs of fire growth behavior in for 20 s ignition exposure of sample combination PU-FB7-C. ................................................................................. 78 Figure 78: Time lapse photographs of fire growth behavior in for 60 s ignition exposure of sample combination PU-FB10-C. ............................................................................... 79 Figure 79: Time lapse photographs of fire growth behavior for 60 s ignition exposure of sample combination PU-W-FB1-C. ........................................................................................ 80 Figure 80: Time lapse photographs of fire propagation and seam penetration in sample combination PU-W-FB1-C. ........................................................................................ 81 Figure 81: Peak heat release rate of mock-up assembly experiments. Error bars are SD for the mean of repeated exposures. ....................................................................................... 83 Figure 82: Total heat release for mock-up assembly experiments. Error bars are SD for the mean of repeated exposures. ................................................................................................. 83 Figure 83: Heat of combustion for mock-up assembly experiments. Error bars are SD for the mean of repeated exposures. ....................................................................................... 84 Figure 84: Polyester wrap effect on heat release rate profiles for PU foam based mock-up assemblies. .................................................................................................................. 85 Figure 85: Polyester wrap effect on heat release rate profiles for frPU foam based mock-up assemblies. .................................................................................................................. 85 Figure 86: Comparison of heat release rates for polyurethane foam and fire-retardant treated foam mock-up assemblies. .......................................................................................... 86 Figure 87: Comparison of heat release rates for polyester wrap covered polyurethane foam and fire-retardant treated foam mock-up assemblies. ........................................................ 87 Figure 88: Comparison of heat release rates for polyester wrap covered polyurethane foam and high-loft fire barrier 7 covered foam mock-up assemblies. ........................................ 88 Figure 89: Comparison of heat release rates for polyester wrap covered polyurethane foam and high-loft fire barrier 8 covered foam mock-up assemblies. ........................................ 88 Figure 90: Comparison of heat release rates for polyester wrap covered polyurethane foam and high-loft fire barrier 9 covered foam mock-up assemblies. ........................................ 89 Figure 91: Comparison of heat release rates for polyester wrap covered polyurethane foam and high-loft fire barrier 10 covered foam mock-up assemblies. ...................................... 89 Figure 92: Comparison of heat release rates for polyester wrap covered polyurethane foam and high-loft fire barrier 11 covered foam mock-up assemblies. ...................................... 90 This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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Figure 93: Comparison of heat release rates for polyester wrap covered polyurethane foam mock-up assemblies with and without flat fire barrier 1. ........................................... 91 Figure 94: Comparison of heat release rates for polyester wrap covered polyurethane foam mock-up assemblies with and without flat fire barrier 2. ........................................... 91 Figure 95: Comparison of heat release rates for polyester wrap covered polyurethane foam mock-up assemblies with and without flat fire barrier 3. ........................................... 92 Figure 96: Comparison of heat release rates for polyester wrap covered polyurethane foam mock-up assemblies with and without flat fire barrier 4. ........................................... 92 Figure 97: Comparison of heat release rates for polyester wrap covered polyurethane foam mock-up assemblies with and without flat fire barrier 5. ........................................... 93 Figure 98: Comparison of heat release rates for polyester wrap covered polyurethane foam mock-up assemblies with and without flat fire barrier 6. ........................................... 93 Figure 99: Single seat upholstered chair frame............................................................................. 98 Figure 100: Furniture at different stages of construction.............................................................. 99 Figure 101: Ignition locations for furniture combustibility experiments of single seat upholstered chairs. ........................................................................................................................ 101 Figure 102: Heat release rate profiles for upholstered chair fire experiments. ........................... 102 Figure 103: Mass loss profiles for upholstered chair fire experiments. ...................................... 103 Figure 104: Fire progression for chair exhibiting rapid development and high peak heat release rate............................................................................................................................. 104 Figure 105: Fire progression for chair exhibiting delayed development and moderate peak heat release rate. ............................................................................................................... 105 Figure 106: Fire progression for chair exhibiting limited burning. ............................................ 106 Figure 107: Furniture calorimeter peak heat release rates. ......................................................... 107 Figure 108: Fire growth rate for furniture calorimeter experiments. Measured peak heat release rates (kW) are listed above the respective experiments. ........................................... 108 Figure 109: Weight loss rate for furniture calorimeter experiments........................................... 108 Figure 110: Heat release rate results for Chair 1 (baseline) ignited at in tested locations. ......... 110 Figure 111: Heat release rate results for ignition of Chair 2 (FR foam) in various locations. ... 111 Figure 112: Heat release rate results for ignition of Chair 3 (High-loft barrier clad foam) in various locations. ...................................................................................................... 111 Figure 113: Heat release rate results for ignition of Chair 4 (Full barrier clad) in various locations. ................................................................................................................... 112 Figure 114: Heat release rate profiles for the four chair styles ignited at the back bottom. ....... 114 Figure 115: Heat release rate profiles for the two barrier clad chair styles ignited at the interior corner. ....................................................................................................................... 115 Figure 116: Heat release rates for PU-W-C chair (interior corner ignition) and mock-up experiments. .............................................................................................................. 116 Figure 117: Heat release rates for frPU-W-C chair (interior corner ignition) and mock-up experiments. .............................................................................................................. 116 Figure 118: Heat release rates for PU-FB8-C cushioned chairs (interior corner ignition) and mock-up experiments. ............................................................................................... 117 Figure 119: Mock-up test frame. ................................................................................................ 127 Figure 120: Heat release rate and sample mass of Chair 1 ignited at the corner. ....................... 128 Figure 121: Heat release rate and sample mass of Chair 2 ignited at the corner. ....................... 129 Figure 122: Heat release rate and sample mass of Chair 3 ignited at the corner. ....................... 129 This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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Figure 123: Heat release rate and sample mass of Chair 4 ignited at the corner. ....................... 130 Figure 124: Heat release rate and sample mass of Chair 1 ignited at the seat/back. .................. 130 Figure 125: Heat release rate and sample mass of Chair 2 ignited at the seat/back. .................. 131 Figure 126: Heat release rate and sample mass of Chair 3 ignited at the seat/back. .................. 131 Figure 127: Heat release rate and sample mass of Chair 4 ignited at the seat/back. .................. 132 Figure 128: Heat release rate and sample mass of Chair 1 ignited at the back bottom. ............. 132 Figure 129: Heat release rate and sample mass of Chair 2 ignited at the back bottom. ............. 133 Figure 130: Heat release rate and sample mass of Chair 3 ignited at the back bottom. ............. 133 Figure 131: Heat release rate and sample mass of Chair 4 ignited at the back bottom. ............. 134

This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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LIST OF TABLES Table 1: Major Causes for Upholstered Furniture Fire (2005 – 2009) ........................................... 1 Table 2: Tests for Resistance to Cigarette Ignition for Upholstered Furniture and its Components ....................................................................................................................................... 2 Table 3: Upholstered Fires and Associated Deaths Stemming from Small Open flame and Smoking Materials. ....................................................................................................... 7 Table 4: Small Open Flame Ignition Tests for Upholstered Furniture ........................................... 7 Table 5: Larger Open Flame Ignition Tests for Upholstered Furniture .......................................... 9 Table 6: List of evaluated material-level samples. ....................................................................... 13 Table 7: Area density of fabric and barrier materials (expressed as mean ±SD). ........................ 22 Table 8: Barrier material thickness (expressed as mean ±SD). .................................................... 22 Table 9: Semi-quantitative elemental analysis by ICP-MS. ......................................................... 29 Table 10: Quantitative elemental analysis results for flame retardant characteristic elements. ... 30 Table 11: SEM-EDS quantified elemental composition (weight fraction) of fabric, foam and barrier materials. ......................................................................................................... 42 Table 12: SEM-EDS quantified elemental composition (atomic fraction) of fabric, foam and barrier materials. ......................................................................................................... 43 Table 13: Potential heat of foams, fabric and barrier materials (expressed as mean ±SD). ......... 44 Table 14: Combustibility characteristics of foam materials (expressed as mean ±SD). .............. 44 Table 15: Material characteristics of cover fabric and decking. ................................................... 46 Table 16: Material characteristics of untreated and treated polyurethane foams (expressed as mean ±SD). ................................................................................................................. 46 Table 17: Material characteristics of flat fire barriers (expressed as mean ±SD). ........................ 47 Table 18: Material characteristics of high-loft fire barriers and polyester wrap (expressed as mean ±SD). ................................................................................................................. 47 Table 19: Component experiment samples for cone calorimeter combustibility measurement. .. 49 Table 20: Ignition behavior of cone calorimeter component arrangements. ................................ 51 Table 21: Burning characteristics of cone calorimeter component arrangements (expressed as mean ±SD). ................................................................................................................. 52 Table 22: Combustibility characteristics of foams with and without cover fabric (expressed as mean ±SD). ................................................................................................................. 64 Table 23: Mock-up assembly experiment sample descriptions. ................................................... 74 Table 24: Mock-up assembly experiment results. ........................................................................ 82 Table 25: Single seat upholstered chair experiment sample descriptions................................... 100 Table 26: Single seat upholstered chair experiment sample mass. ............................................. 100 Table 27: Furniture combustion conditions at peak heat release rate. ........................................ 107 Table 28: Average peak heat release rate and standard deviation for each chair type ............... 112

This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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INTRODUCTION For more than 20 years, upholstered furniture and mattresses/bedding fires have resulted in more residential fire deaths than any other item.5 In 2006, the Consumer Product Safety Commission (CPSC) developed and implemented the Standard for the Flammability (Open Flame) for Mattress Sets 6 to address the fire performance of mattresses when exposed to open flame ignition sources. The criteria for compliance set in the standard were feasible in part due to innovations in thermal barrier (interliner) technology. The set of experiments described in this report were conducted to explore whether or not the same mitigation approach can be effective for upholstered furniture, for the purpose of reducing the flammability of upholstered furniture and the deaths, injuries, and property losses due to upholstered furniture fires. Between 1980 and 2009, residential structure fires originating with upholstered furniture declined from 36,900 to 5,600. 7 While the number of upholstered furniture fires has been significantly reduced since 1980, they remain persistent and deadly. During the 2006 to 2010 time period these fires resulted in annual averages of 480 civilian deaths, 840 injuries, and more than $427 million in direct property damage.4 The National Fire Protection Association (NFPA) reported that “fires beginning with upholstered furniture accounted for 2% of reported home fires but one of every five (19%) home fire deaths.” Table 1 lists the major causes of upholstered furniture fires between 2005 and 2009.6 Table 1: Major Causes for Upholstered Furniture Fire (2005 – 2009) Ignition Source Smoking materials Intentional Candle Hot ember or ash Heating equipment Electrical distribution or light source Playing with heat source

% Fires 28 13 10 10 9 9 8

% Deaths 58 6 6 7 7 11 5

% Injuries 38 8 12 10 6 10 9

In approximately 76% of upholstered furniture fires, the fire growth extended beyond the upholstered furniture resulting in 94% of the total upholstered furniture fire fatalities. Fires originating with upholstered furniture can be categorized into three general classes: 1. Small smoldering ignition source such as a cigarette, cigar or other smoking material 2. Large smoldering ignition source such as a portable heater 3. Small open flame ignition source such as a candle, match, or lighter

5

Ahrens, M. “Home Structure Fires”, National Fire Protection Association, United States (2012). 16 CFR Part 1633 Standard for the Flammability (Open Flame) for Mattress Sets, U.S. Consumer Public Safety Commission, United States. (March 15, 2006). 7 Ahrens, M. “Home Fire that Began with Upholstered Furniture”, National Fire Protection Association, United States (2011). 6

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FIRES ORIGINATING FROM SMOLDERING IGNITION SOURCES Fires Originating from Smoking Materials (small smoldering ignition source) Smoking materials still represent the largest percentage of ignition sources for fires and related deaths and injuries. Most of these fires are started by either discarded cigarettes or cigarettes in close proximity of the upholstered furniture. There are several standard test methods available that test the ignition resistance of upholstered furniture components and products to cigarettes. These test methods are summarized in Table 2. Table 2: Tests for Resistance to Cigarette Ignition for Upholstered Furniture and its Components Test Method 8 CA TB 116 9 CA TB 117 10111213141516 UFAC 17 NFPA 260 , 18 ASTM E 1353 19 16 CFR Part 1634 20 NFPA 261 , 21 ASTM E 1352 22 BS 5852 23 EN 1021

Sample Large scale mock-up or commercially available furniture Small scale mock-up Small scale mock-up Small scale mock-up Small scale mock-up Large scale mock-up Small scale mock-up or commercially available furniture

8

California Technical Bulletin 116 Requirements, Test Procedure and Apparatus for Testing the Flame Retardance of Upholstered Furniture, California Bureau of Home Furnishings and Thermal Insulation, United States (Jan. 1980). 9 California Technical Bulletin 117 Requirements, Test Procedure and Apparatus for Testing the Flame Retardance of Resilient Filling Materials Used in Upholstered Furniture, California Bureau of Home Furnishings and Thermal Insulation, United States (March 2000). 10 Fabric Classification Test Method, Upholstered Furniture Action Council, United States (1990) 11 Interior Fabrics Test Method, Upholstered Furniture Action Council, United States (1990) 12 Barrier Test Method, Upholstered Furniture Action Council, United States (1990) 13 Decking Material Test Method, Upholstered Furniture Action Council, United States (1990) 14 Filling/Padding Components Test Methods, Upholstered Furniture Action Council, United States (1990) 15 Decorative Trims Test Method, Upholstered Furniture Action Council, United States (1990) 16 Welt Cord Test Method, Upholstered Furniture Action Council, United States (1990) 17 NFPA 260 Standard Methods of Tests and Classification System for Cigarette Ignition Resistance of Components of Upholstered Furniture, National Fire Protection Association, United States (2013). 18 ASTM E 1353 Standard Test Methods for Cigarette Ignition Resistance of Components of Upholstered Furniture, ASTM International, United States (2008). 19 16 CFR Part 1634 Standard for the Flammability of Residential Upholstered Furniture; Proposed Rule, US Consumer Product Safety Commission, United States (March 4, 2008). 20 NFPA 261 Standard Method of Test for Determining Resistance of Mock-Up Upholstered Furniture Material Assemblies to Ignition by Smoldering Cigarettes, National Fire Protection Association, United States (2013). 21 ASTM E 1352 Standard Test Method for Cigarette Ignition Resistance of Mock-Up Upholstered Furniture Assemblies, ASTM International, United States (2008). 22 BS 5852 Methods of Test for Assessment of the Ignitability of Upholstered Seating by Smouldering and Flaming Ignition Sources, British Standards Institute, United Kingdom (2006). 23 EN 1021-1 Furniture - Assessment of the ignitability of upholstered furniture - Part 1: ignition source smouldering cigarette, European Committee for Standardization, Belgium (2006). This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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The samples in the test methods are broken down into three different size categories: small scale mock-up, large scale mock-up, and commercially available furniture. The small scale mock-up assembly cigarette resistance test methods (CA TB 117, UFAC test methods, NFPA 260, ASTM E 1353, 16 CFR Part 1634, BS 5852, and EN 1021) are similar to one another and consist of a foam and fabric combination to form a seat and back arrangement, such as Figure 1. In the American test methods (CA TB 117, UFAC test methods, NFPA 260, ASTM E 1353, and 16 CFR Part 1634) the frame holding the arrangement is wood, while in the European test methods (BS 5852 and EN 1021) the frame is steel. In these tests, a cigarette is placed on the cover fabric in the crevice formed at the intersection of the back and seat. In the American test methods, the cigarette is also covered with a smoldering-prone fabric. Performance is characterized by either char length or mass loss, and observation of transition from smoldering to flaming combustion.

Figure 1: CPSC Cigarette Ignition Resistance Test (reprinted from 16 CFR Part 1634)

CA TB 117 also has provisions for evaluating the upholstered furniture filling material. Whether a sample passes or fails is dependent on the char length and mass loss of the filling material. The sample fails if the maximum char length is greater than 2 inches in any direction. It will also fail if, in two or more of the samples, the remaining unburned sample is less than 80% of the original weight. The small scale mock-up test methods developed by the Upholstered Furniture Action Council (UFAC), American Society of Testing and Materials (ASTM), and NFPA are nearly identical. The test methods divide the performance of the samples into Class I or Class II. These test methods include a test method to address each of the following components of upholstered furniture: cover fabric, interior fabric, welt cord, filling/padding, decking material, and barrier material. Class I components do not ignite during the test and char less than 38 mm to 51 mm in the vertical direction (the char length requirements change depending on the component being tested). Any samples that do not meet the Class I requirements are categorized as Class II.

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Similarly, the CPSC developed test method, 16 CFR Part 1634, consists of a small-scale arrangement and is shown in Figure 1. Compliant designs are also divided into two categories – Type I and Type II. Type I upholstered furniture are finished articles constructed with cover fabrics or other covering materials that are smolder-resistant in accordance with the cover fabric performance test (Section 1634.4). Type II upholstered furniture are finished articles constructed with internal barriers (placed between cover fabrics and any interior filling materials) that are smolder and open flame-resistant in accordance with two barrier performance tests (Sections 1634.5 and 1634.6). Type I compliance testing is conducted on mock-up arrangements of the standard polyurethane foam (SPUF) substrate covered with the upholstery cover fabric under investigation. Compliance is demonstrated if: a) mock-up self-extinguishes within the 45 minute test period, b) there is no transition to flaming combustion during the test period, and c) mass loss of the SPUF substrate shall not exceed 10%. Type I furniture may be constructed with any interior filling materials and no upholstery materials other than cover fabrics need be qualified. Articles of upholstered furniture with noncomplying cover fabrics are required to have Type II barriers. Type II compliance testing is conducted on mock-up arrangements of the internal fire barrier under investigation placed between the standard polyurethane foam (SPUF) and a standard cover fabric. Compliance is demonstrated if: a) there is no transition to flaming combustion during the test period for the smoldering test scenario mock-up (Section 1634.5), b) mass loss of the SPUF substrate for the smoldering test scenario mock-up (Section 1634.5) does not exceed 1%, and c) total mass loss of the flaming test scenario mock-up (Section 1634.6) does not exceed 20%. Type II furniture may be constructed with any cover fabrics and any interior fillings and no upholstery materials other than barriers need be qualified. Unlike the previously mentioned test methods, the British Standard (BS) 5852 addresses the flammability of the combined material components of upholstered furniture in a small scale mock-up, instead of a test method for each component incorporated in a standardized small scale mockup. In this test method, the sample’s performance is determined by if and when the sample ignites, and if it ignites, whether or not it is flaming ignition or progressive smoldering. BS 5852 defines progressive smoldering as: a) “any test specimen that displays escalating smoldering combustion behavior so that it is unsafe to continue the test and forcible extinction is required b) any test specimen that smolders to the full thickness of the test specimen, or to more than 50 mm from the nearest part of the cigarette, within 60 min of placement of the cigarette c) any test specimen that produces externally detectable amounts of smoke, heat or glowing 60 min after placement of the cigarette… d) any test specimen that, on final examination, shows evidence of charring within the filling (other than discoloration) more than 100 mm in any direction, apart from upwards, from the nearest part of the original position of the source”

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The standard defines flaming ignition as: a) “any test specimen that displays escalating flaming combustion behavior so that it is unsafe to continue and forcible extinction is required b) any test specimen that burns until it is essentially consumed within the test duration c) any test specimen on which any flame front reaches the extremities of the specimen other than the top of the vertical part of the test specimen or passes through the full thickness of the test specimen within the duration of the test d) the occurrence of any visible flaming within 60 min of placement of the cigarette… e) any test specimen from which debris causes an isolated floor fire not meeting the requirements of (the previous) item” In European Standard EN 1021, the test method is similar. The most significant difference is the definition of progressive smoldering and flaming ignition. In this standard progressive ignition is defined as: a) “any test assembly that displays escalating combustion behaviour so that it is unsafe to continue the test and active extinction is necessary; b) any test assembly that smoulders until it is largely consumed within the test duration; c) any test assembly that smoulders to the extremities of the specimen, viz. upper or lower margins, either side or to its full thickness, within the duration of the test; d) any test assembly that smoulders after one hour from the beginning of the test; e) any test assembly that, on final examination, shows evidence of active smouldering” In EN 1021, flaming ignition is the presence of any flame. In addition to small scale mock-up tests, there are large scale mock-up and commercially available furniture tests. Large scale mock-ups consist of the upholstered furniture components being arranged to resembled furniture of parts of furniture. The samples can consist of the materials arranged and sized to simulate an arm and part of the back and seat of a sofa, for example. In all of the following test methods the material components are evaluated together in one sample. CA TB 116, NFPA 261, ASTM E 1352, and BS 5852 address large scale mock-ups and/or commercially available furniture. In each of the standards, multiple burning cigarettes are applied to the horizontal surfaces, crevices, edges, and any depressions that might exist in the materials of the mock-up or furniture. CA TB 116 includes multiple tests addressing the smooth surfaces, decking, welts, quilted locations, tufted locations, crevices, tops of the arms and back, and covering materials of the sample. In each, three burning cigarettes are applied to the area. The sample fails if it begins to flame or char more than two inches in any direction. NFPA 261 and ASTM E 1352 differ from CA TB 116 in that the burning cigarettes are placed on similar areas of concern on one test sample during one test instead of multiple tests and samples. In NFPA 261 and ASTM E 1352, the standards require reporting of the maximum char distance and when ignition occurs at each location. In BS 5852, only three locations are tested: one on the seat and two on the floor – one underneath the furniture and one on the side of the furniture. The reporting for the commercially available furniture test method within BS 5852 is almost the same as the small scale mock-up, described This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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earlier. The definition for flaming ignition also includes “any test specimen on which any flame front reaches the extremities of the specimen other than the top of the vertical part of the test specimen, within the duration of the test.” Fires Originating from Heating Equipment (large smoldering ignition source) NFPA analysis of fires in home structure shows that portable and fixed heating equipment including wood stoves were responsible for 8% of the fires and 7% of associated fatalities involving the upholstered furniture as the first item ignited.24 It is conjectured that these fires may occur when the upholstered furniture is in close proximity to the heating unit. Currently, there are no standard tests for upholstered furniture that use radiant heating as the ignition source. However, ASTM E 1354 Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Calorimeter 25 offers a potential small-scale test method to evaluate fabric and foam combinations exposed to radiant heat in a manner similar to the conditions that may be encountered by heating equipment placed close to an upholstered furniture item. Fires Originating from Electrical Distribution and Light Sources NFPA analysis of fires in home structure shows that electrical malfunction was a factor in an annual average of 630 fires originating from upholstered furniture.26 Of these, lamps and lighting equipment were involved in an average of 200 fires and 20 deaths per year, cords and plugs in 160 fires and 40 deaths, and wiring, switches, and outlets in another 240 fires. In most cases involving wiring and cords, fires start when localized arcing and overheating occur in damaged wiring. In cases involving lamps, a potential scenario is the close proximity of the lamp to the upholstered furniture causing localized heating of the furniture fabric and ignition. While there are no standardized tests representing electrical fires used to test upholstered furniture, the open flame source may be able to represent a fire started with localized arcing and overheating. Fires resulting from close proximity to lamps may be represented by radiant heating provided by the Cone Calorimeter (ASTM E 1354). FIRES ORIGINATING FROM OPEN FLAMES Small open flames such as candles, matches or lighters represent a different exposure threat than smoldering induced by smoking materials or heating equipment. Upholstered furniture fires started by small open flames are less likely to be confined to the object of origin or room of origin than fires started by smoking materials, Table 3 (note that smoldering fires must transition to open flame fires in order to spread beyond the object of origin). It is also important to note that when the small open flame induced fire was confined to the upholstered furniture item, there 24

Ahrens, M. “Home Fire that Began with Upholstered Furniture”, National Fire Protection Association, United States (2011). 25 ASTM E 1354 Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Calorimeter, ASTM International, United States (2013). 26 Ahrens, M. “Home Fire that Began with Upholstered Furniture”, National Fire Protection Association, United States (2011). This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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were no fatalities reported. This suggests that limiting the fire growth from an upholstered furniture item can provide significantly improve safety. Table 3: Upholstered Fires and Associated Deaths Stemming from Small Open flame and Smoking Materials. % of Fires Open Smoking Flame Materials 24 32 35 32 10 10 28 23 3 3

Extent of Flame Damage Confined to object of origin Confined to room of origin Confined to floor of origin Confined to building of origin Extending beyond building of origin

% of Deaths Open Smoking Flame Materials 0 10 17 25 27 16 47 45 9 3

There are several standard test methods available to determine the performance of upholstered furniture components using a small open flame as an ignition source. These are summarized in Table 4. Table 4: Small Open Flame Ignition Tests for Upholstered Furniture Source Number -

28

Gas flame

1

2

0.077

20

29

Gas Flame

1

2

0.077

15

CA TB 117 BS 5852

Energy (KJ) (kW) 1 0.046

Ignition Type Gas flame

Test Standard

EN 1021

27

Flame Duration (s) 12

Sample Small scale mock-up Small scale mock-up or commercially available furniture Small scale mock-up

California TB 117 is a component test for upholstered furniture filling materials. Depending upon the form of the component material, it is evaluated as either an independent component material or in a component mock-up with a standard cover fabric:  Resilient cellular materials (e.g. foam) are tested by direct exposure to flame source for 12 seconds and the pass/fail criteria is char length, flame duration and glowing combustion duration (Section A Part I)  Resilient cellular materials used in shredded form are further tested in a “pillow” configuration to an open flame exposure for up to 12 seconds and the pass/fail criteria is mass loss (Section A Part II)  Expanded polystyrene beads are directly exposed to a flame generated by methenamine reagent tablet and the pass/fail criteria is mass loss (Section A Part III)  Non-man-made fillings are directly exposed to flame source for 12 s, pass/fail criteria is char length and flame duration (Section B Part I)

27

California Technical Bulletin 117 Requirements, Test Procedure and Apparatus for Testing the Flame Retardance of Resilient Filling Materials Used in Upholstered Furniture, California Bureau of Home Furnishings and Thermal Insulation, United States (March 2000). 28 BS 5852 Methods of Test for Assessment of the Ignitability of Upholstered Seating by Smouldering and Flaming Ignition Sources, British Standards Institute, United Kingdom (2006). 29 EN 1021-2 Furniture - Assessment of the ignitability of upholstered furniture - Part 2: ignition source match flame equivalent, European Committee for Standardizations, Belgium (2006) This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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 

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Feathers and down are tested in a “pillow” configuration to an open flame exposure for up to 12 seconds and the pass/fail criteria is mass loss (Section B Part II) Man-made fiber fillings are directly exposed to flame for 5 seconds and the pass/fail criteria is burn duration (Section C)

Test method BS 5852 provides provisions for evaluating upholstered furniture component materials in a composite, small scale mock-up arrangement (Section 4) or as full furniture pieces (Section 5). The mock-up arrangement consists of vertically and horizontally oriented components which comprise a single combination of covering fabric, fire barrier (if used), and filling material as used in the upper 75 mm (3 in.) of the upholstery in the upholstered furniture. Under the full-furniture provision, the furniture piece is evaluated to ignition exposures to both the seating surface as well as from underneath. The pass/fail criteria is the same for the two approaches - presence of flaming combustion more than 120 seconds after removal of the ignition source flame and presence of heat, glowing, or smoke production more than 15 minutes after removal of the ignition source flame. The ignition flame, Source 1, is similar in size to that produced by a match or a cigarette lighter and is frequently referred to as “match-flame equivalent”. Test method EN 1021 is similar to the small scale mock-up used in BS 5852 exposed to a Source 1 flame. The duration of the flame exposure is 5 seconds less in EN 1021 than BS 5852. This test method does not provide pass/fail criteria. It does, however, require whether or not the sample ignited to be recorded and if it did ignite, when it ignited and whether or not it was progressive smoldering or flaming ignition. Progressive smoldering is defined by EN 1021 Part 2 as: “a) any test assembly that displays escalating combustion behaviour so that it is unsafe to continue and test and active extinction is necessary; b) any test assembly that smoulders until it is largely consumed within the test duration; c) any test assembly that smoulders to the extremities of the specimen, viz. upper or lower margins, either side or to its full thickness, within the duration of the test; d) any test assembly that smoulders after one hour from the beginning of the test; e) any test assembly that, on final examination shows evidence of active smouldering. Flaming ignition is defined by EN 1021 Part 2 as: “a) any test assembly that displays escalating combustion behaviour so that it is unsafe to continue the test and active extinction is necessary; b) any test assembly that burns until it is essentially consumed within the test duration; c) any test assembly on which any flame front reaches the lower margin, either side or passes through its full thickness within the duration of the test; d) any flaming which continues for more than 120 s after removal of the burner tube.” There are also a number of standard test methods available to determine the performance of upholstered furniture and its components using larger open flames, larger than candles, matches or lighters. These are presented in Table 5.

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Table 5: Larger Open Flame Ignition Tests for Upholstered Furniture Test Standard CA TB 133

30

ASTM E 1537 32 NFPA 266

34

Source Number

Flame Duration (s)

Gas flame

-

1600

20

80

Gas flame

-

1600

20

80

Gas flame Gas flame Gas flame Wood crib Wood crib Wood crib Wood crib

3 2 3 4 5 6 7

42 11 42 142 285 1040 2110

0.602 0.275 0.602 1 1.9 2.6 6.4

70 40 70 Burn-out Burn-out Burn-out Burn-out

31

16 CFR Part 1634

BS 5852

Energy (KJ) (kW)

Ignition Type

33

Sample Large scale mock-up or commercially available furniture Large scale mock-up or commercially available furniture Small scale mock-up Small scale mock-up or commercially available furniture

Test methods California TB 133, ASTM E 1537, and NFPA 266 are calorimeter tests using the full furniture (a large scale mock-up furniture assembly or commercially available product) as the test sample whereas in 16 CFR Part 1634 the test sample is a small scale mock-up. BS 5852 provides test methods for both full furniture and small scale mock-ups. In California TB 133 the test sample is located in a 12 × 8 ft. room with one 2 × 7 ft. doorway opening. ASTM E 1537 allows the test to be conducted with the test sample either in a room or directly under a calorimeter. The NFPA 266 is a calorimeter test only. A full furniture item or mock-up consisting of seat, back and side arm cushions may be used in the ASTM E 1537 and NFPA 266 test methods. All the tests employ a 10 × 10 in. (250 × 250 mm) square burner placed over the seat of the upholstered furniture or mock-up as an ignition source with a heat output of approximately 20 kW. These tests when conducted under the calorimeter permit measurement of heat release rates, smoke release rates, and weight loss. Tests conducted in the room also permit measurement of the temperature of the hot gas layer, smoke obscuration, and carbon monoxide gas concentration. If the calorimeter is used in the test, the CAL TB 133 has fire performance requirements for upholstered furniture with respect to (i) peak heat release rate (< 80 kW); (ii) total heat released (< 25 MJ during the first 10 minutes); (iii) smoke opacity (< 75% in the room at 4 ft. height); and (iv) carbon monoxide concentration (not greater than 1000 ppm for 5 minutes). 30

California Technical Bulletin 133 Flammability Test Procedure for Seating Furniture for Use in Public Occupancies, California Bureau of Home Furnishings and Thermal Insulation, United States (Jan. 1991). 31 ASTM E 1537 Standard Test Method for Fire Testing of Upholstered Furniture, ASTM International, United States (2013). 32 NFPA 266 Standard Method of Test for Fire Characteristics of Upholstered Furniture Exposed to Flaming Ignition Source, National Fire Protection Association, United States (1998). 33 16 CFR Part 1634 Standard for the Flammability of Residential Upholstered Furniture; Proposed Rule, US Consumer Product Safety Commission, United States (March 4, 2008). 34 BS 5852 Methods of Test for Assessment of the Ignitability of Upholstered Seating by Smouldering and Flaming Ignition Sources, British Standards Institute, United Kingdom (2006). This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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If the calorimeter is not used in the test, the CAL TB 133 has fire performance requirements with respect to (i) peak temperature at the ceiling (< 200 °F); peak temperature at 4 ft. level (< 50 °F); smoke opacity (< 75 % in the room at 4 ft. height); (iv) carbon monoxide concentration (not greater than 1000 ppm for 5 minutes); and sample weight loss (< 3 pounds during the first 10 minutes of burning). The requirements with and without the calorimeter measurements are similar, as relationships between heat release rate and temperature have been established by McCaffrey et. al.35. The weight loss and total heat generated requirements are also related through the heat of combustion of the polyurethane foam (18 kJ/g) that is a key combustible component of the upholstered furniture BS 5852 evaluations of upholstered furniture component materials (Section 4) and full-furniture pieces (Section 5) using the increasingly larger flame sources are conducted the same as with the small flame source (Source 1). The pass/fail criteria for the two larger gas flame sources (2 and 3) are the same as for Source 1 – presence of flaming combustion more than 120 seconds after removal of the ignition source flame and presence of heat, glowing, or smoke production more than 15 minutes after removal of the ignition source flame. The pass/fail criteria for wood crib sources is presence of heat, glowing, or smoke production more than 60 minutes after ignition of the wood crib and the presence of flaming combustion more than 10 minutes after ignition of wood crib Sources 4 and 5 or 13 minutes for wood crib Sources 6 and 7. The longer acceptable flaming combustion durations for the wood crib sources are essentially two minutes longer than the time necessary for the cribs to be consumed. Should the sample burn to an extremity other than the top of the vertical part, it is considered a failure. The proposed CPSC open flame ignition test (16 CFR Part 1634, Section 1634.6) is used when the sample fails the cigarette ignition resistance test. The open flame ignition test uses a similar test method to the component mock-up test method in BS 5852 with the Source 3 flame. In the proposed CPSC test method, the “mockup must not exceed 20% mass loss by the end of the 45 minute test. 10 initial samples are tested. If there is a failure with any of the 10 specimens, an additional 20 specimens are tested, and at least 25 of the 30 must meet the criteria for the sample barrier to pass.”36

35

McCaffrey, B.J., Quintiere, J.G., and Harkleroad, M.F. “Estimating Room Temperatures and the Likelihood of Flashover Using Fire Test Data Correlations”, Fire Tech, pp. 99-119 (1981). 36 16 CFR Part 1634 Standard for the Flammability of Residential Upholstered Furniture; Proposed Rule, US Consumer Product Safety Commission, United States (March 4, 2008). This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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PROJECT OBJECTIVE AND TECHNICAL PLAN The investigation focused on exploring whether commercially available flame retardant treated foam and fire barrier technologies can retard and/or reduce the fire growth rate of upholstered furniture when exposed to small open flames. OBJECTIVES The objectives of this study were to: 1. Explore strategies for the improvement of the fire performance of upholstered furniture with respect to small open flame ignition sources. 2. Determine the influence of location of ignition on fire growth of full furniture chairs 3. Investigate the effect of sample size on fire growth The objectives were accomplished through the following technical plan. LIMITATIONS IN SCOPE This study was focused on the flammability performance of materials and components used in upholstered furniture. Flame retardant chemistry and concentration effects on flammability performance were limited to the investigated materials. The study did not cover:  Effectiveness of the fire mitigation approaches on occupant safety and egress  Furniture comfort, durability and wear performance, and aesthetics  Furniture construction practicality and affordability Information conveyed by this report applies only to the specimens actually involved in these experiments. The results may not be fully representative of all furniture constructions available in the marketplace today. Thus, results should not be extrapolated to furniture comprised of different materials, component arrangements, design geometry and features. TECHNICAL PLAN The technical plan consisted of six tasks that are summarized below. Task 1 – Select and Procure Sample Materials In this task, commercially available component materials intended for use in upholstered furniture were selected and procured. Component materials included a cover fabric, polyurethane foams with and without flame retardant treatment, and various fire barriers based upon their chemical and physical attributes. Task 2 – Characterization of Sample Materials The selected sample materials were characterized for density, chemistry, thermal degradation behavior, and combustibility. Compliance of the foams and cover fabric to appropriate residential upholstered furniture standards was also verified. Task 3 – Material Combination Combustibility Experiments The combustibility of various combinations of foam, polyester wrap, barrier material and cover fabric as would be used in upholstered furniture construction practice was characterized under flaming conditions by oxygen consumption calorimetry (cone calorimeter) to assess materiallevel performance differences. This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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Task 4 – Mock-Up Assembly Combustibility Experiments In this task, different strategies for reducing and/or retarding fire growth were evaluated against a baseline scenario to determine if commercially available products (e.g. FR foams, fire barriers) can retard and reduce the fire growth rate in mock-ups exposed to an open flame ignition source. Task 5 – Full-Scale Furniture Combustibility Experiments The combustibility of single seat upholstered chairs exposed to an open flame ignition source was characterized to assess system level performance of full-scale furniture. Chairs were constructed using four different combinations of foam, polyester wrap, fire barrier material, and cover fabric evaluated in Task 4. Task 6 – Develop Technical Report A comprehensive technical report was developed to summarize the details of the materials, experiment samples and procedures, and the results obtained. The report also provides recommendations for future study. The results of this investigation (Task 6) are described herein.

This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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TASK 1 – SELECT AND PROCURE SAMPLE MATERIALS Commercially available cover fabric, foams, and fire barriers representative of those prevalently used in residential upholstered furniture and mattresses were selected for this study. The cover fabric selected was the most popular cover fabric from the largest upholstered furniture cover fabric supplier in the United States. The polyurethane foam was selected based on most commonly used density in upholstered furniture37, use for compliance testing residential sprinklers (UL 162638), and potential use for compliance testing smoke detectors and alarms (UL 21739 and UL 26840). Two versions of the foam were included in the study – a California Technical Bulletin 117 (TB 117)41 compliant foam and a flame retardant free foam as specified for residential sprinkler and smoke detector and alarm testing. Eleven different barrier products were selected from a list of barrier products recommended by barrier manufacturers for use in upholstered furniture. Selection of these barriers was based on their chemical and physical attributes as well as prevalence in the market. The purchased materials are identified and described in Table 6. Photographs of the cover fabric, decking, polyester wrap, and fire barriers follow in Figure 2 through Figure 14. Table 6: List of evaluated material-level samples. Material ID C D PU frPU W FB1 FB2 FB3 FB4 FB5 FB6 FB7 FB8 FB9 FB10 FB11

Material Description Cover fabric: beige, polyester microsuede Decking: beige cotton twill (nominal 8 oz) Polyurethane foam Flame retardant treated polyurethane foam Polyester wrap: 1 oz smooth bond Fire barrier 1: Para-aramid-PET-Rayon blend nonwoven flat sheet Fire barrier 2: Para-aramid blend nonwoven flat sheet Fire barrier 3: Woven flat sheet 2 Fire barrier 4: Elastic knit flat sheet (nominal 5.5 oz/y ) 2 Fire barrier 5: Elastic knit flat sheet (nominal 7.0 oz/y ) 2 Fire barrier 6: Elastic knit flat sheet (nominal 5.0 oz/y ) 2 Fire barrier 7: Cotton based high-loft (nominal 1.0 oz/y ) 2 Fire barrier 8: Two layer (rayon/cotton) high-loft (nominal 0.75 oz/y ) 2 Fire barrier 9: Rayon based high-loft (nominal 1.0 oz/y ) 2 Fire barrier 10: Three layer (rayon/rayon/cotton) high-loft (nominal 0.8 oz/y ) Fire barrier 11: Cotton-viscose rayon blend high-loft

37

Knudtson, L. “Smolder Testing Evaluation of Selected Cigarettes”, Presented at: ASTM E05.15 Furnishings and Contents. Atlanta, Georgia, United States (December 5, 2012). 38 UL 1626 Residential Sprinklers for Fire-Protection Service, Underwriters Laboratories Inc., United States (2008). 39 UL 217 Single and Multiple Station Smoke Alarms, Underwriters Laboratories Inc., United States (2006). 40 UL 268 Smoke Detectors for Fire Alarm Systems, Underwriters Laboratories Inc., United States (2009). 41 California Technical Bulletin 117 Requirements, Test Procedure and Apparatus for Testing the Flame Retardance of Resilient Filling Materials Used in Upholstered Furniture, California Bureau of Home Furnishings and Thermal Insulation, United States (March 2000). This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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Figure 2: Polyester microsuede cover fabric (C)

Figure 3: Polyester wrap (W)

Figure 4: Fire barrier 1 (FB1)

Figure 5: Fire Barrier 2 (FB2)

Figure 6: Fire Barrier 3 (FB3)

Figure 7: Fire Barrier 4 (FB4)

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Figure 8: Fire Barrier 5 (FB5)

Figure 9: Fire Barrier 6 (FB6)

Figure 10: Fire Barrier 7 (FB7)

Figure 11: Fire Barrier 8 (FB8)

Figure 12: Fire Barrier 9 (FB9)

Figure 13: Fire Barrier 10 (FB10)

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Figure 14: Fire Barrier 11 (FB11)

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TASK 2 – CHARACTERIZATION OF SAMPLE MATERIALS Acquired sample materials were characterized for physical, chemical, and thermal characteristics by a variety of analytical techniques. Measure physical properties included thickness and density; chemical composition was characterized by Fourier Transform Infrared Spectroscopy (FTIR), elemental analysis (ICP-MS), and pyrolysis-GC-MS (Py-GC-MS); and thermal characteristics included thermal degradation behavior, potential heat and combustibility. The two foams, PU and frPU, were evaluated for compliance to California Technical Bulletin 117 (TB 117) by the California Bureau of Home Furnishings and Thermal Insulation (BHFTI)42. The frPU foam was found to be compliant and the PU foam was found to be non-compliant. EXPERIMENTAL Density Area density of the fabric, polyester wrap, and fire barriers was determined by averaging the 10 specimens per sample. Specimen measuring 50.8 × 50.8 mm (2.0 × 2.0 in.) were cut using die avoiding the fabric selvage and weighed on an analytical balance with a sensitivity of 0.0001 g. Volume density of the foams was determined from 100 × 100 × 51 mm (4.0 × 4.0 × 2.0 in.) samples. Three specimen of each foam type were measured using a caliper with a sensitivity of 0.01 mm and an analytical balance with a sensitivity of 0.0001 g. Thickness The uncompressed thickness of fire high-loft barriers was determined with a sensitivity of 0.01 mm. Reported results are the average of 10 specimens per sample. Flat barrier thickness was measured using a Federal Product Corp; Model d71 dial micrometer (85 g force exerted over 31.7 mm2) with a sensitivity of 0.01 mm. Reported results are the average of 10 specimens per sample. Chemistry (FTIR) Infrared spectral response of the materials was characterized in the solid-state using a Nicolet Nexus 470 FTIR with a Golden Gate KRS-5 diamond ATR accessory. Samples were scanned from 400 to 4000 cm-1 wavenumber at a 4 cm-1 resolution; 32 scans were averaged per recorded spectra. Elemental Analysis (ICP-MS) Semi-quantitative analysis of the materials for elemental metals and some non-metals by inductively coupled plasma-mass spectroscopy (ICP-MS). Testing was performed by Galbraith

42

California Bureau of Home Furnishings and Thermal Insulation, 4244 South Market Ct., Suite D, Sacramento, CA 95834, United States. This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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Laboratories43 following procedure ME-31 (Semi-Quantitative Metals Screen by Mass Spectrometry). ICP-MS is a highly sensitive method for quantifying metals and some non-metals at ppm and lower concentrations. The technique couples an ICP with a mass spectrometer. Prior to analysis, approximately 0.5 g samples were acidified or digested using appropriate sample digestion methods. The resulting aqueous sample solution was then introduced into a calibrated ICP instrument where the liquid carrier was evaporated and any dissolved solids were atomized for detection in a mass spectrometer. Concentration was determined by comparison of the mass-tocharge ratio of each element in the sample solution to the mass-to-charge ratio of the same element in the calibration solution. Materials were tested for (listed in order of elemental mass): Lithium, Beryllium, Boron, Sodium, Magnesium, Aluminum, Phosphorus, Potassium, Calcium, Scandium, Titanium, Vanadium, Chromium, Manganese, Iron, Cobalt, Nickel, Copper, Zinc, Gallium, Germanium, Arsenic, Selenium, Rubidium, Strontium, Yttrium, Zirconium, Niobium, Molybdenum, Ruthenium, Rhodium, Palladium, Cadmium, Indium, Tin, Antimony, Tellurium, Cesium, Barium, Lanthanum, Cerium, Praseodymium, Neodymium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Hafnium, Tantalum, Tungsten, Rhenium, Iridium, Platinum, Gold, Thallium, Lead, Bismuth, Thorium, and Uranium. Minimum detection limits for all elements was typically 2 ppm; minimum detection limits for iron and gold analysis of some samples were 20 ppm. Measurement accuracy for the utilized semi-quantitative method was ±50 %. Quantitative Elemental Analysis (Boron, Bromine and Chlorine) Materials that had cotton as a component (FB7-11) were further analyzed for quantitative assessment of boron content by ICP-AES using simultaneous optical systems and axial or radial viewing of the plasma. Testing was performed by Galbraith Laboratories44 following procedure ME-70 (Inductively Coupled Plasma Atomic Emission Spectrometry). Prior to analysis, approximately 100 mg samples were acidified or digested using appropriate sample preparation method. The resulting solution was nebulized and the resulting aerosol was transported to the plasma torch. Element-specific emission spectra were produced by radiofrequency inductively coupled plasma. The spectra were dispersed by a grating spectrometer, and the intensities of the emission lines were monitored by photosensitive devices. Background correction was required for trace element determination. Background were measured adjacent to analyte lines on samples during analysis. The position selected for the background-intensity measurement, on either or both sides of the analytical line, was determined by the complexity of the spectrum adjacent to the analyte line. In one mode of analysis the position used was as free as possible from spectral interference and reflected the same change in background intensity as occurs at the analyte wavelength measured. Background correction was not required in cases of

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Galbraith Laboratories Inc., PO Box 51610, Knoxville, TN 37950-1610, United States. Galbraith Laboratories Inc., PO Box 51610, Knoxville, TN 37950-1610, United States. This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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line broadening where a background correction measurement would actually degrade the analytical result. Measurement accuracy for the ME-70 quantitative method was ±10 %. The foam and fire barrier materials were further analyzed by ion chromatography for quantitative assessment of bromine and chlorine content. Samples weighing between 400 and 800 mg were tested by Galbraith Laboratories45 following procedure ME-4A (Determination of Anions by Suppressed Ion Chromatography). Measurement accuracy for the ME-4A quantitative method was ±10 %. Foam and fire barrier materials exhibiting chlorine concentrations exceeding than the 2 % upper concentration limit of the ME-4A quantitative assessment of bromine and chlorine content method were also titrated by Galbraith Laboratories46 using procedure E17-1 (Determination of Total Halogens or Total Halides by Potentiometric Titration) to assess halogen content. To determine the total halogen content, 20 to 70 mg samples were converted to halides by (Schoniger) oxygen flask combustion (G-54 or ASTM E-442) absorbed in a 2% hydrazine sulfate solution (liquid samples were weighed into gelatin capsules prior to combustion). Chloride, bromide, and iodide were automatically titrated with dilute AgNO3 potentiometrically to calculate the resulting Total Halogens as Chlorine. Measurement accuracy for the E17-1 quantitative method was ±0.71 %. Pyrolysis-GC/MS (Py-GC/MS) Volatile, semi-volatile and non-volatile components present in the fabric, foam, and barrier materials were analyzed with a Frontier Laboratories PY-2020iD Py-GC/MS. Approximately 0.1 mg solid samples were placed in the Auto-Shot Sampler for introduction into the pyrolyzer furnace. Released compounds were trapped and focused in a Micro-Jet Cryo Trap before being introduced into the gas chromatography column. The carrier gas was 99.995% pure helium and the separation column was a stainless-steel capillary coated with 5% diphenyldimethyl polysiloxane (Ultra ALLOY-5: 30 m length, 0.25 mm inner diameter with 0.25 μm of the film thickness, Frontier Laboratories). Compounds were eluted at different retention times to a mass spectrometer downstream. The mass spectrometer broke each molecule into ionized fragments and detected the fragments by their mass to charge ratio. The pyrolyzer furnace was operated in three analysis modes: 1. Evolved Gas Analysis (EGA) for the polymer identification: The sample was introduced into the 50 °C furnace, held for 1 minute to equilibrate, and then heated to 700 °C at a rate of 20 °C/min. The polymeric material was identified by comparison of the EGA data to an EGA library. 2. Thermal Desorption (TD): The sample was injected at 50 °C, held for 1 minute to equilibrate, and then heated to 350 °C at a rate of 20 °C/min. As the temperature increased, individual compounds desorbed from the sample and were carried to the splitter and ultimately to the MS detector. The elute compounds were identified by comparison to either NIST or F-Search Additive libraries.

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Galbraith Laboratories Inc., PO Box 51610, Knoxville, TN 37950-1610, United States. Galbraith Laboratories Inc., PO Box 51610, Knoxville, TN 37950-1610, United States. This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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3. Pyrolysis: The sample was introduced into the 550 °C furnace where it was pyrolyzed into characteristic fragments. Polymer species were identified through collection of the pyrolyzed fragments and comparison to an F-Search Polymer/Pyrolyzate library. Testing was conducted in triplicate. Thermal Degradation (TGA) Thermal degradation behavior of the fabric, foam, and barrier materials was characterized using a TA Instruments model Q500 TGA with an evolved gas analysis (EGA) furnace. Samples weighing between 10 to 50 milligrams were heated from 40 to 850 °C at 20 °C/min under a 90 mL/min dry air flow rate. SEM-EDS Fabric, foam, and barrier materials were analyzed using a Jeol JSM-6701F scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDS) to determine the inorganic content of the fabric, foam, and barrier materials. Samples were coated with a thin layer of gold for electric conductivity. Analysis was performed under high vacuum conditions utilizing a 20kV accelerating voltage and a working distance of approximately 15 mm. The electron beam current was 10 A and the measuring time was 60 s. Potential Heat Potential heat of the materials was measured in accordance with NFPA 259 Standard Test Method for Potential Heat of Building Materials 47 using a Parr oxygen isoperibol bomb calorimeter under a high-pressure oxygen environment. The bomb calorimeter is calibrated by one-gram benzoic acid pellets with a known heat of combustion of 26.43 kJ/g (11,373 BTU/lb). A gross calorific value is defined as the amount of heat liberated per unit mass of a sample when burned in oxygen at a constant volume vessel. Combustibility The combustibility behavior of the untreated and flame retardant treated foams was characterized under flaming conditions using a cone calorimeter in accordance with test method ASTM E 1354 Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Calorimeter 48. Foam test specimen measuring 100  100 mm square by 51 mm thick were cut and tested in a horizontal orientation using an edge frame sample holder with a restraining grid (HEG) such that the intended outer surface of the material was exposed to the applied radiant heat flux, Figure 15.

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NFPA 259 Standard test Method for Potential Heat of Building Materials, National Fire Protection Association, United States (20130. 48 ASTM E 1354 Standard Test Method for Heat and Visible Smoke Release Rates for Materials and Products Using an Oxygen Consumption Calorimeter, ASTM International, United States (2013). This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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Figure 15: ASTM E1354 Cone calorimeter sample holder

Tests were performed, in triplicate, at 30 kW/m2 radiant heat flux setting on the conical heater and using an electric spark igniter to ignite the thermal decomposition gases. Data was collected until flaming or other signs of combustion ceased. Samples were exposed until flaming combustion ceased for more than 2 minutes or for a maximum of 60 minutes (as specified in ASTM E 1354) in order to collect sufficient data for this investigation. Observations regarding ignition time and physical changes to the sample (e.g. melting, swelling, or cracking) were also noted. Heat release rates and effective heats of combustion were calculated using the procedures described in ASTM E 1354 and are summarized in the following equations. HRR =

Measured heat [=] kW/m2 Sample area completion

Total Heat =

ignition

HRR  dt

1000 MJ / kJ

Effective Heat of Combustion =

[=] MJ/m2

Total Heat  Sample area [=] kJ/g Total weight loss  1000 kJ/MJ

Eq. 1

Eq. 2

Eq. 3

RESULTS Density The PU foam volume density (and SD) was measured to be 29.6 ±0.6 kg/m3; the frPU foam was measured to be 27.6 ±0.6 kg/m3. Area densities measured for the fabric and barriers are listed in Table 7.

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Table 7: Area density of fabric and barrier materials (expressed as mean ±SD). Material ID C D W FB1 FB2 FB3 FB4 FB5 FB6 FB7 FB8 FB9 FB10 FB11

2

Area Density (g/m ) 717.9 ±6.3 1036.1 ±15.4 1443.9 ±83.7 295.8 ±21.3 268.7 ±12.6 463.6 ±5.1 869.6 ±27.5 1177.6 ±32.0 684.6 ±4.7 1325.6 ±143.9 1095.7 ±93.3 1434.3 ±54.7 1060.4 ±123.5 1548.2 ±127.2

Thickness Measured flat barrier and uncompressed high-loft barrier thickness are listed in Table 8. Table 8: Barrier material thickness (expressed as mean ±SD). Material ID FB1 FB2 FB3 FB4 FB5 FB6 FB7 FB8 FB9 FB10 FB11

Thickness (mm) 0.3 ±0.0 0.4 ±0.0 0.1 ±0.0 0.6 ±0.0 0.8 ±0.0 0.3 ±0.0 7.3 ±0.6 8.0 ±0.7 8.3 ±0.4 10.1 ±0.8 7.2 ±0.7

Chemistry (FTIR) Measured FTIR spectra for the materials are shown in Figure 16 through Figure 25. Analysis of the spectra indicated both the face and back-side of cover fabric C were polyester and were consistent with the polyester wrap W (Figure 16). Foam spectra for the foams (Figure 17) indicated that the foams were a polypropylene oxide polyol, polyether based polyurethane. Results for the two para-aramid flat sheet barriers FB1 and FB2 confirmed the para-aramid base material and revealed the incorporation of polyester and rayon in FB1 (Figure 18). The FR coated glass-fiber sheet FB3 appears to be either a melamine derivative or a styrene/acrylic derivative (Figure 19). Elastic knit flat barriers FB4 and FB5 were based on a PAN-PVC copolymer and chemically the same (Figure 20); elastic knit flat barrier FB6 appeared to be based on PAN-PVC but also incorporated cotton (Figure 20). High-loft barrier FB7 was determined to be predominantly cotton whereas high-loft barrier FB9 was predominantly rayon, and both exhibited evidence of PET (Figure 21). Multilayer high-loft barriers FB8 and FB10 had This Report cannot be modified or reproduced, in part, without the prior written permission of Underwriters Laboratories Inc. Copyright © 2013 Underwriters Laboratories Inc.

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sides that were predominantly cotton or rayon, and both exhibited evidence of PET (Figure 22 and Figure 23 respectively). High-loft barrier FB11 was found to be a mixture of cotton, rayon and PET (Figure 24). Decking D was determined to be cotton (Figure 25).

Figure 16: FTIR spectra for cover fabric C and polyester wrap W.

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Figure 17: FTIR spectra for PU and frPU foams.

Figure 18: FTIR spectra for para-aramid flat fire barriers FB1 and FB2.

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Figure 19: FTIR spectra for flat fire barrier FB3.

Figure 20: FTIR spectra for elastic knit flat fire barriers FB4, FB5, and FB6.

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Figure 21: FTIR spectra for cotton high-loft fire barrier FB7 and rayon high-loft fire barrier FB9.

Figure 22: FTIR spectra for two-layer (cotton/rayon) high-loft fire barrier FB8.

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Figure 23: FTIR spectra for three-layer (cotton/rayon/rayon) high-loft fire barrier FB10.

Figure 24: FTIR spectra for high-loft fire barrier FB11.

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Figure 25: FTIR spectra for decking D.

Elemental Analysis (ICP-MS) The foams, fabric and barriers were analyzed for inorganic element content. Of the 65 investigated elements, 52 elements were detected at trace concentrations or not detected. These elements were (listed in order of elemental mass): Lithium, Beryllium, Scandium, Vanadium, Chromium, Manganese, Cobalt, Nickel, Copper, Gallium, Germanium, Arsenic, Selenium, Rubidium, Yttrium, Zirconium, Niobium, Molybdenum, Ruthenium, Rhodium, Palladium, Cadmium, Indium, Tellurium, Cesium, Barium, Lanthanum, Cerium, Praseodymium, Neodymium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Hafnium, Tantalum, Tungsten, Rhenium, Iridium, Platinum, Gold, Thallium, Lead, Bismuth, Thorium, and Uranium. Measured concentrations of the remaining 13 elements (Boron, Sodium, Magnesium, Aluminum, Phosphorus, Potassium, Calcium, Titanium, Iron, Zinc, Strontium, Tin, and Antimony) are listed in Table 9.

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P. 29 Table 9: Semi-quantitative elemental analysis by ICP-MS.

Calcium

Titanium

Iron

Zinc

Strontium

Tin

Antimony

C 2 55 39 45 25 D 10 341 515 25 162 PU 2 78 26 56 65 frPU 5 81 43 89 5063 W