Skip to main content
U.S. flag

An official website of the United States government

Vertical Upward Flamespread on Parallel Panels

Research Overview

Quantitative measurements and visual observations were obtained from a series of 66 full-scale fire growth experiments conducted on 18 unique combustible solids including: natural and synthetic polymers, copolymers, fiberglass-reinforced composite materials, porous polymer foams, and electrical cables. Some of these materials were selected because they can be found in electrical cabinets and circuit boards. Others were selected in order to provide a wide range of material compositions and burning behaviors: physical deformation, soot formation, and varied ignitability and fire growth rate. In a typical electrical enclosure, combustible solids (e.g., wiring or circuit boards) are most often found attached to the inside walls of the enclosure. A test setup was designed to represent this configuration: two parallel panels were assembled such that they could support combustible solids of varying thicknesses, which were then ignited at their base. By maintaining this simplified configuration across each test: (1) a large-scale burning scenario representative of typical fuel loading in an electrical enclosure was produced and (2) experiments could be repeated to highlight the impact of material composition on observed burning behavior while minimizing test sensitivity to variations in other factors such as fuel loading, configuration, or orientation.

Experiment Name Plot of Heat Release Rate Ignition Photo Date/Time Sort descending Specimen Fuel Type Test Duration (min) Total Heat Released (MJ) Peak HRR (kW)
Test1_PMMA_R1 1/4" thick, 24" wide, 96" tall panels of cast Black PMMA Polymethyl methacrylate (PMMA)
27.02
506
2,540
Test2_PMMA_R2 1/4" thick, 24" wide, 96" tall panels of cast Black PMMA Polymethyl methacrylate (PMMA)
18.55
506
2,882
Test3_PMMA_R3 1/4" thick, 24" wide, 96" tall panels of cast Black PMMA Polymethyl methacrylate (PMMA)
17.17
506
3,197
NGQC_6m_20kgs_3MW tube gas burner Natural Gas
23.23
2,127
3,022
Test4_PMMA_R4 1/4" thick, 24" wide, 96" tall panels of cast Black PMMA Polymethyl methacrylate (PMMA)
19.22
504
3,140
Test5_PMMA_R5 1/4" thick, 24" wide, 96" tall panels of cast Black PMMA Polymethyl methacrylate (PMMA)
24.10
504
3,166
Test6_Redboard_R1 1/4" thick, 24" wide, 96" tall panels of GPO-3 Polyester resin (GPO-3, Redboard)
25.27
43.0
134.3
Test7_PMMA_R6 1/4" thick, 24" wide, 96" tall panels of cast Black PMMA Polymethyl methacrylate (PMMA)
15.48
503
3,579
Test8_Redboard_R2 1/4" thick, 24" wide, 96" tall panels of GPO-3 Polyester resin (GPO-3, Redboard)
24.80
37.8
114.9
Test9_SIS_wire_R1 90 vertically oriented strands of SIS wire XLPE (SIS Wire)
16.20
16.0
132.8
Test10_SIS_wire_R2 96 vertically oriented strands of SIS wire attached to 1/4" thick, 24" wide, 96"tall panels of GPO-3 XLPE (SIS Wire) and (GPO-3)
27.05
47
142
Test11_PVC_R1 1/4" thick, 24" wide, 96" tall panels of PVC Polyvinyl chloride (PVC)
35.40
61.9
163.2
Test12_PBT_R1 1/4" thick, 24" wide, 96" tall panels of PBT Polybutylene terephthalate (PBT)
31.17
375
2,821
Test13_PVC_R2 1/4" thick, 24" wide, 96" tall panels of PVC Polyvinyl chloride (PVC)
32.95
84.0
236
Test14_Redboard_R3 1/4" thick, 24" wide, 48" tall panels of GPO-3 Glass-reinforced polyester resin (GPO-3, 'Redboard')
21.48
36.2
109.6
BurnerShakedownO1 sand burner box Propane
10.17
37.7
71.2
Test15_RedCedar_R1 7/8" thick, 22.5" wide, 96" tall planks of Western Red Cedar Western Red Cedar
32.90
139
307
Test16_HDPE_R1 1/4" thick, 24" wide, 96" tall panels of HDPE High Density Polyethelyne (HDPE)
9.47
284
2,817
Test17_GPO1_R1 1/4" thick, 24" wide, 96" tall panels of GPO-1 Polyester resin (GPO-1)
23.18
235
498
Test18_XLPE2_R1 1" thick, 24" wide, 96" tall panels of XLPE Foam (2lb/ft3 density) Cross-linked polyethylene foam (XLPE)
8.85
101.4
3,992
Test19_XLPE6_R1 1" thick, 24" wide, 96" tall panels of XLPE Foam (6lb/ft3 density) Cross-linked polyethylene foam (XLPE)
12.30
278
3,500
Test20_OSB_R1 7/16" thick, 24" wide, 96" tall panels of OSB Oriented Strand Board (OSB)
15.28
243
622
Test21_Polyiso_R1 1" thick, 24" wide, 96" tall panels of Polyisocyanurate Foam Polyisocyanurate Foam (foil-backed)
7.20
28.6
949
Test22_RedCedar_R2 7/8" thick, 22.5" wide, 96" tall planks of Western Red Cedar Western Red Cedar
9.70
44.4
322
Test23_XLPE2_R2 1" thick, 24" wide, 96" tall panels of XLPE Foam (2lb/ft3 density) Cross-linked polyethylene foam (XLPE)
11.90
104.9
4,186
Test24_Polyiso_R2 1" thick, 24" wide, 96" tall panels of Polyisocyanurate Foam Polyisocyanurate Foam (foil-backed)
5.08
32.0
974
Test25_Polyiso_R3 1" thick, 24" wide, 96" tall panels of Polyisocyanurate Foam Polyisocyanurate Foam (foil-backed)
5.05
31.0
954
Test26_Polyiso2_R1 2" thick, 24" wide, 96" tall panels of Polyisocyanurate Foam Polyisocyanurate Foam (foil-backed)
9.45
37.6
784
Test27_Polyiso2_R2 2" thick, 24" wide, 96" tall panels of Polyisocyanurate Foam Polyisocyanurate Foam (foil-backed)
9.12
38.8
801
Test28_POMGF_R1 1/4" thick, 24" wide, 96" tall panels of POM-GF Polyoxymethylene (POM-GF)
63.10
387
503
Test29_Kydex_R1 1/4" thick, 24" wide, 96" tall panels of Kydex Kydex (PVC-acrylic copolymer)
34.53
111
1,060
Test30_Kydex_R2 1/4" thick, 24" wide, 96" tall panels of Kydex Kydex (PVC-acrylic copolymer)
46.10
182
1,070
Test31_Polyiso05_R1 1/2" thick, 24" wide, 96" tall panels of Polyisocyanurate Foam Polyisocyanurate Foam (foil-backed)
1.70
18.6
1,056
Test32_Polyiso05_R2 1/2" thick, 24" wide, 96" tall panels of Polyisocyanurate Foam Polyisocyanurate Foam (foil-backed)
1.52
18.2
997
Test33_XPSpink1_R1 1" thick, 24" wide, 96" tall panels of Pink XPS Foam Extruded Polystyrene Foam (XPS)
12.67
50.4
812
Test34_XPSgreen1_R1 1" thick, 24" wide, 96" tall panels of Green XPS Foam Extruded Polystyrene Foam (XPS)
13.73
54.9
1,255
Test35_XPSpink1_R2 1" thick, 24" wide, 96" tall panels of Pink XPS Foam Extruded Polystyrene Foam (XPS)
13.17
47.1
1,080
Test36_XPSgreen1_R2 1" thick, 24" wide, 96" tall panels of Green XPS Foam Extruded Polystyrene Foam (XPS)
13.25
49.1
628
Test37_OSB_R2 7/16" thick, 24" wide, 96" tall panels of OSB Oriented Strand Board (OSB)
16.37
243
894
Test38_XLPE6_R2 1" thick, 24" wide, 96" tall panels of XLPE Foam (6lb/ft3 density) Cross-linked polyethylene foam (XLPE)
10.22
280
3,459
Test39_XLPE6_R3 1" thick, 24" wide, 96" tall panels of XLPE Foam (6lb/ft3 density) Cross-linked polyethylene foam (XLPE)
10.20
301
3,427
Test40_GPO1_R2 1/4" thick, 24" wide, 96" tall panels of GPO-1 Glass-reinforced polyester resin (GPO-1)
24.80
246
469
Test41_XPSPink2_R1 2" thick, 24" wide, 96" tall panels of Pink XPS Foam Extruded Polystyrene Foam (XPS)
13.28
100.6
1,687
Test42_XPSGreen2_R1 2" thick, 24" wide, 96" tall panels of Green XPS Foam Extruded Polystyrene Foam (XPS)
14.75
105
1,946
Test43_RedCedar_R3 7/8" thick, 22.5" wide, 96" tall planks of Western Red Cedar Western Red Cedar
5.35
38.8
398
Test44_Polyiso05_R3 1/2" thick, 24" wide, 96" tall panels of Polyisocyanurate Foam Polyisocyanurate Foam (foil-backed)
1.72
17.9
1,022
Test45_HIPS_R1 1/4" thick, 24" wide, 96" tall panels of HIPS High Impact Polystyrene (HIPS)
33.82
509
2,955
Test46_HIPS_R2 1/4" thick, 24" wide, 96" tall panels of HIPS High Impact Polystyrene (HIPS)
33.22
504
3,228
Test47_ABS_R1 1/4" thick, 24" wide, 96" tall panels of ABS Acrylonitrile Butadiene Styrene (ABS)
35.22
547
3,821
Test48_XPSpink1_R3 1" thick, 24" wide, 96" tall panels of Pink XPS Foam Extruded Polystyrene Foam (XPS)
13.08
55.3
1,332
Test49_GPO1_R3 1/4" thick, 24" wide, 96" tall panels of GPO-1 Polyester resin (GPO-1)
19.67
232
522
Test50_POMGF_R2 1/4" thick, 24" wide, 96" tall panels of POM-GF Polyoxymethylene (POM-GF)
50.42
367
540
Test51_ABS_R2 1/4" thick, 24" wide, 96" tall panels of ABS Acrylonitrile Butadiene Styrene (ABS)
35.23
566
3,538
Test52_HIPS_R3 1/4" thick, 24" wide, 96" tall panels of HIPS High Impact Polystyrene (HIPS)
34.98
535
3,094
BurnerShakedown21 Sand Burner Propane
6.50
22.9
71.0
Test53_ABS_R3 1/4" thick, 24" wide, 96" tall panels of ABS Acrylonitrile Butadiene Styrene (ABS)
36.98
550
3,541
Test54_XPSpink2_R2 2" thick, 24" wide, 96" tall panels of Pink XPS Foam Extruded Polystyrene Foam (XPS)
22.77
84.5
1,510
Test55_XPSgreen2_R2 2" thick, 24" wide, 96" tall panels of Green XPS Foam Extruded Polystyrene Foam (XPS)
25.32
110
1,839
Test56_HIPS_R4 1/4" thick, 24" wide, 96" tall panels of HIPS High Impact Polystyrene (HIPS)
66.20
513
3,173
Test57_OSB_R3 7/16" thick, 24" wide, 96" tall panels of OSB Oriented Strand Board (OSB)
22.27
262
526
Test58_XLPE4_R1 1" thick, 24" wide, 96" tall panels of XLPE foam (4lb/ft3 density) Cross-linked polyethylene foam (XLPE)
7.70
211
3,169
Test59_XLPE4_R2 1" thick, 24" wide, 96" tall panels of XLPE foam (4lb/ft3 density) Cross-linked polyethylene foam (XLPE)
9.95
149.1
2,876
Test60_XLPE4_R3 1" thick, 24" wide, 96" tall panels of XLPE foam (4lb/ft3 density) Cross-linked polyethylene foam (XLPE)
8.15
174.4
2,830
Test61_POMGF_R3 1/4" thick, 24" wide, 96" tall panels of POM-GF Polyoxymethylene (POM-GF)
81.63
452
536
Test62_XPSgreen1_R3 1" thick, 24" wide, 96" tall panels of Green XPS Foam Extruded Polystyrene Foam (XPS)
15.67
22.9
174
Test63_XPSpink2_R3 2" thick, 24" wide, 96" tall panels of Pink XPS Foam Extruded Polystyrene Foam (XPS)
17.75
93.2
1,580
Test64_XPSgreen2_R3 2" thick, 24" wide, 96" tall panels of Green XPS Foam Extruded Polystyrene Foam (XPS)
24.92
97.8
1,426
BurnerShakedown27 Sand Burner Propane
6.65
22.7
70.7
Test65_RedCedar_R4 7/8" thick, 22.5" wide, 96" tall planks of Western Red Cedar Western Red Cedar
10.23
65.1
378
Test66_HIPS1panel_R1 one 1/4" thick, 24" wide, 96" tall panel of HIPS High Impact Polystyrene (HIPS)
42.50
274
1,465

Bryant, R. and Bundy, M. The NIST 20 MW Calorimetry Measurement System for Large-Fire Research, Technical Note (NIST TN) 2077, 2019
https://doi.org/10.6028/NIST.TN.2077(link is external)

NIST Fire Calorimetry Database (FCD)
https://doi.org/10.18434/mds2-2314(link is external)

Last Updated March 6, 2024