Click for next page ( 16


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 15
Chapter 4 CLAS SIFICAT ION OF VA~OUS DUSTS OSHA requested that the committee classify dusts according to the NEC. The materials considered are listed in Table 4-1, which was taken from Table 3-8A of the NFPA's Fire Protection Handbook, 14th edition. The next to last column of Table 4-1 1lsts the classifications of these materials according to the 1981 edition of the NEC. The methodology used in classifying the dusts is described in Chapter 3 of this report. The last column of Table 4-1 lists classifications according to the recommended scheme described in Chapter 3 and illustrated in Figure 3-2. It is recognized that the materials tabulated in Table 4-1 do not include all of the potentially hazardous dusts that might be found in industry, particularly in the future. The choice of compounds listed was based on the availability of data. 15

OCR for page 15
16 TABLE 4-1 Classification of Dusts by National Electrical Codea. Max. Max. Rate Ignition Min. Ot' Temperature Cloud Min. Ignition E:xplosion Ignition Explo- Explosion Pressure Sensi- sion Pressureb Riseh tivity Severity (psi") Type of Dust NEC Classification Cloud Layer Energy Concentration (C) (J. (oz/cu ft) 1981 Recommended 1. Agricultural Dusts Alfalt'a meal 0.1 1.2'' 66 1,100 460 200 0.32 0.100 G G Almond shell 0.9 0.3 72 800 440 200 0.08 0.065 G G Apricot pit 1.6 1.2 94 2,500 440 230 0.08 0.035 G G Cellulose 1.0 2.8 119 4,500 480 270 0.080 0.055 G G Cellulose, alpha 2.7 4.4 106 8,000 410 300 0.040 0.045 G G Cellulose, flock, f~ne cut i.S 3.8 103 7,000 420 260 0.035 0.055 G G Cereal grass <0.1 0.1 52 500 550 220 0.80 0.20 G d C~herry pit 2.0 2.2 104 4,000 430 220 0.08 0.03 G G Ctnnarnon 2.5 2.3 114 3,900 440 230 0.03 0.06 G G Citrus peel 1.1 0.96 5 I 1,200 490 270 0.06 0.06 G G Coca bean shell 3.6 3.8t 69 3,300 470 370 0.03 0.04 G G Cocoa natural. 19'7, t'at 0.5 1.1< 53 1,200 510 240 0.10 0.075 G G Coconut shell 2.0 2.1 97 4,200 470 220 0.06 0.035 G G Coft'ee. raw bean 0.1 0.1' 33 150 650 280 0.32 0.15 G d Coft'ee. fully roasted ().2 ().1' 38 150 720 270 0.16 0.085 G G (~offee. instant spray-dried ().1 44 500 410 350 C 0.28 G ~ (~orn 2.3 3.0 95 6.000 400 250 0.04 0.055 G G Corncob grit 2.2 1.8 11() 3.100 450 240 0.045 0.045 G G (~orn dextrine, pure 3.1 3.9 105 7,000 400 370f 0.04 0.04 G G Cornstarch, commercial product 2.9 4.0 108 7,000 380 330f 0.04 0.045 G G Cornstarch (thru No. 325 sieve) 4.3 5.4 115 9,000 390 3501 0.03 0.04 G G Cork dust 3.6 3.3 96 7,500 460 210 0.035 0.035 G G Cotton [inter, raw _ <(1.1 <~0.1 48 15() 520 - 1.92 0.50 G ~ C~ottonieed meal 1.4 1.2 104 2,200 470 200 0.06 0.05 G G Cube root, South An~erican 2.7 2.4' 69 2,100 470 230 0.04 0.04 G G Egg white <0.1 0.2 58 500 610 - 0.64 0.14 G d l 'fax strive ().7 0.3 81 80() 430 230 0.08 0.08 G G Garlic, dehydrated 0.2 1.2` 57 1.3()() 360 --- 0.24 0.10 G G (,rain dust, winter wheat. corn, `~ats 2.P; 3.3 115 5.500 430 230 0.03 0.055 (i G (;rassseed. blr~e ().1 ().1' 24 200 490 180 0.26 0.29 G ~ Guar seed 1 7 1 4' 7() 1,200 500 - 0.06 0.04 G (; Gum. arabic ().7 1.6'' 6S 1,5()0 500 260 0.10 0.06 G G (;um.karaya ().2 1 5'' 8() 1,100 520 240 0.18 O.10 G G (;um, Ma~,ila (ct,l1Ul) 6.7 2.9' 63 2.8()0 360 39~ 0.03 0.03 G ~ Gum. tra~eacanth 2.3 3.()'' 78 2,4(i(, 490 260 0.045 0.04 G (; Plemp hurd 3 ~ 5.4 1()3 1().00() 440 220 0.035 0.04 G (; Lycop<'diu~n 4.2 3 7' 75 3.1()() 48() 310 0.04 0.025 G (; Malt baric.` 2.6 2.1 92 4.4t)0 4()() 250 0.035 0.055 G G Milk. skimnied 1.6 ().9 83 2,1t)() 490 200 0.05 0.05 G (i Moss, Irish ~ <0.1 12 30() 48() 230 '' ~ G d Onion, dehydrated <().1' 18 10() 41 () - ~ 0.13 (j ct Pea flour 1.8 2.1'' 68 1,90() 560 260 0.04 0.05 G G Peach-pit shell 3.1 2.3 98 4,40() 440 210 0.05 0.03 G G Peanut hull 1.9 2.0 82 4,70() 460 210 0.05 0.045 G G Peat, sphagnum sun-dried 1.9 2.0 87 4.400 460 240 0.05 O.W5 G G Pecan-nut shell 3.1 2.4 106 4.400 440 210 0.05 0.03 G G Pectin (t'rom ground dried apple pulp) 1.9 4.7 112 8.00() 410 200 0.035 0.075 G (; Potato starch, dextrinated 4.1 4.1 97 8,000 440 - ' 0.025 0.045 G (; Pyrcthrum, ground tlower l~:aves 0.5 0.6 82 1.501) 460 210 0.08 0.10 G G Rauwolfia vomitoria root 1.9 4.2 106 7,50() 420 230 0.045 0.055 G G Rice 1.8 1.3 93 2,60() 440 220 0.05 0.05 G G Rice bran 1.1 1.3' 61 1.3()0 490 -- 0.08 0.045 G (; Rice hull 1.6 1.7 90 3,6()0 450 220 0.05 0.055 G G SafNower meal 3.2 1.3 84 2,900 460 210' 0.025 0.055 G G Soy flour 0.6 1.1t' 79 800 540 19() 0.10 0.06 G (i Soy protein 2.2 3.3 96 6.500 520 260 0.05 0.035 G (i Sucrose. chemically pure 1.1 2.9t 71 2,500 420 470f 0.10 0.045 G G Sucrose 4.1 1.8'' 66 1,8()0 350 4601 0.04 0.035 G G Sugar. powdered 4.0 2.4 91 5,000 370 400f 0.03 0.045 G (; Tea, instant, spray-dried - <0.1 30 250 580 340 c R G d l'obacco stem - <0.1 7 200 420 230 c R G d Tung kernels, oil-t'ree 0.2 2.3C 74 1,900 540 240 0.24 0.07 G (; Walnut shell, black 3.0 1.7 97 3,300 450 220 0.05 0.03 G (; Wheat, untreated 1.() 1.9 103 3.600 500 220 0.06 0.065 G G Wheat nOur 2.1 1.8 95 3,700 380 360 0.05 0.05 G G Wheat gluten, gum 1.0 ~ 5 20 - 0.08 0.05 G Gth

OCR for page 15
17 TABLE 4-1 Classification of Dusts by National ~ I, am -~1 sure, ~yl ~l~e leaked ~1 saw Wow, birch bag, Hound -~ noun whim paw Yeast, Aruba 2. (carbonaceous Dusts Ch~cod, h~dwo~ moue Charcoal, activated, Rom bEnite Carbon, ac~va~d Tom Quorum add dug Guano, use ~1~, cog tar In_ resin In, Ileum Lampblack ~ bug, ~~ In, Quorum coke and pitch electrodes C-, Kennedy ~hum~ou~ (Experimental mine coal) Coal, Pennsylvania (anthracite) Coke, petroleum Graphite Lignite, Cali~mi. 1. Comics AN ^celoace1-~loluid~e O~e~y~l=~un~) ^=l-~enedd~ ^dipic acid AnlhraniDc acid gal Nan methyl ~+ ^zelaic acid 2,2'-Azobisis~'bulyroni1 rile Benzoic acid n~ B-~ ^ Dehydroacelic acid Diallyl Hale ~_H Next Bong ~0~ yd~n--e dioxin Dimelhyl isoph~ale _1 ~~ 3,5-Dinilro~nzoic acid + 0~1m onto ~u~- Dipheny 1 awl_ ~1 ~1 gum .. . . . rummy am I~xame~y~- ~1~- Hyd~xye~yl heroic anhydride d~e~i~- Nilrosoamine on ~e~ h~ pheny~ne dame (misdo Penlaerythrilol ~1 ~ _~- ~^ Ida Phlhalimide Sign E~- Sensi- sion livily Severity 4.1 1.4 8.S 1.1 1.6 1.1 ].7 1.8 l1, 1~ 1.6 1.4 1.4 0.9 Max. Explosion gum (psi") 100 98 99 98 110 105 100 6.9 1.5 78 1,700 4.0 2.8 88 6,000 2.8 2.2 85 5,000 2~ 1~ 71 1 2.2 1.8 1.0 1.0 5.7 1.8 7.6 1.9 1 2 >4.9 1.7 1.1 1.1 1.6 5.5 1.1 5.1 1.2 12.! 4.3 5.4 5.1 1 1.8 3.0 4.4 10.4 7.0 2.7 2.5 1 ~7 l8 9.1 2.9 5.9 5.8 1.9 2.1 5.4 10.7 10.7 8.6 1.3 12.7 4.9 1.1 6.2 5.0 17.7 4.1 7.2 16.8 4.7 13.8 2.1 00 go 8] 90 89 78 76 77 90 67 102 74 1~3 82 2.5 7] . O oO .0 00 2.4 85 1~4 82 2.7 79 74 85 79 92 92 106 1{ 82 3.9 82 0.7 84 1.2 79 5.6 98 1.4 106 2.0 . 80 1.5 92 8.5 125 2.4 77 2.1 85 2.8 82 45 90 1.S 68 1.6 72 1.9 79 Electrical Code (contId] Max. Rale ignition Chug Risen (psi/s) Min. ('loud Min. lotion Explosion Cloud Layer Energy Concentration ') (ec) (j) (oz/cu fl) 4~> 6~- 380 6,000 470 3~- 450 5~- 470 2~ 520 1 ~- 5 10 4,000 2,100 8.000 4,100 >10~0 2,700 3,900 7,00{) 1,50() 8,{,oo 5,300 7~600 6~00 3,900 5,500 8,000 6,500 6~300 8,500 7,000 1 2,000 4,3{}0 > 1 0~00 3,700 9,000 1 ,500 2,900 1 1~000 2.600 4.700 1.100 1' and . ~ 6.000 4,700 6.500 9,500 4,)00 4,200 4,500 590 370 760 490 580 500 710 - 510 550 630 - 730 520 900 870 - 600 1 80 610 710 270 ]90 440 170 C 400 200 380 18() 71() 56f) 55{} 5R() 49[) 614} 434} 35(~/ 44() ~ 7() 64{) 65~) 41{] 48{) 560 180 420 580 570 46(} 500 630 47() 391) 520 410 410 700 370 360 270 - 380 430 620 560 400 680 650 630 0.~)25 220 0.050 250 0.060 260 0.~0 ~0 ~0 1 ~ ~0 0.025 0.055 0.020 0.0]5 0.050 0.140 2.00 0.025 0.020 0.020 0.035 ~0 -~ ~5 _ - 0.030 9.060 0.03{) 0.050 0.035 1.00 0.030 ~0~ ~030 - 0.010 {~.060 (~.035 {~.() 1 ~ 0.~)25 41.{)25 {J ()2() O.(j3() {).{~15 0.{)30 0.020 {~.()15 0.020 0.030 O.OlO 0.015 0.020 0.~5 0.015 0.020 0.020 0.030 0.015 0.010 0.040 0.025 0.035 0.060 0.015 0.030 0.025 0.0~0 0.{)25 0.015 {).05{) ().030 0.035 {1,03{) 0 {~50 t'4~25 {of) 1 ~ O.t}3t) 1) {)34; 0.02U 0.035 0.035 0.030 0.030 0.~5 0.015 0.025 0.030 0.050 0.050 0.015 0.020 0.020 0.085 0.015 0.025 0.035 0.025 0.025 0.020 0.025 0.020 0.030 (}.025 0.015 0.030 NEC Classincalion 1981 G G G G G G 17 17 F F'' 17 F F 1; F 17 F 17 F F 1: 1' G G G G (; (; (; G G G G G G G G G G G G G G G G G G G G G (; Recommen~d G G G G G G G14 GtA G G G G GIR GtA GIR G G GIA GIR G G GIA (; (; (, t. (; (; G G G G G G G G G G G G G G G G G G G G 6 G G G G G

OCR for page 15
18 TABLE 4-1 Classification of Dusts by National Electrical Code (cont'd) Type of Dust Salicy lanilide Sorbic acid Stearic acid, aluminum salt (aluminum tristearate) Stearic acid, zinc salt (zinc stearate) Sulfur Terephthalic acid 4. Drugs 2-Acetylam~nm5-nitrothiazole Max. Rate Ignition Min. Max. of Temperature Cloud Min. NEC Ignition Exploit Explosion Pressure Ignition Explosion Classification Sensi- sion Pressureb Riseb Cloud Layer Energy Concentration tivity Severity (psi") (psi/s) (C) (C) (J) (oz/cu ft) 1981 Recommended 4.1 1.4 14.3 -4.6 33.6 3.5 19.7 3.4 20.2 1.9 3.0 2.3 ().7 4.4 2-Amin>5-nitrothiazole 1.9 Aspirin (acetylsalicylic acid) Mannitol Nitropyridone l-Sorbose Vitamin B', mononitrate Vitamin C. ascorbic acid 5. Dyes, Pigments, and - Intermediates - 1,4-Diamino-2, 3- dihydroanthraquin<,nc (9()';. ), I-methylaminoanthraguinonc ( 10'7, ) (Viols t 200 dye) 1 ,4-Di-p-toluidineanthra- quinone (70~%,), ,6-naphthalene-azo~i~,ethyl- aniline (30~,) (green base Harmon dye) I -Methylaminoanthraquinone (red dye intermediate) ,8-Naph thalene-azo- dimethylaniline 6. Me tats Aluminum, atomized collector fines Aluminum, flake, A 422 extra fine lining, polished Antimony, milled (957, Sb) Boron, amorphous, commercial (85~ B) Cadmium, atomized (987, Cd) Chromium, electrolytic, milled (97'7, Cr) Cobalt, milled (97.87 Co) Copper, electrolytic, Type (' (99.5% Cu) Iron, hydrogen reduced (98'%, I:e) Iron, carbonyl (99'/., Pe) Lead, aton~ized ( 99Y. Pb) Magnesium, milled, Grade B Manganese N ickel Selenium, milled Silicon, milled (96'/ Si) Tantalum Tellurium, electrolytic (98'7, Te) 61 4,400 88 >10,00() 88 68 78 73 93 2.8 2.4 >4.3 4.8 3.0 >5.8 1.0 1.9 2.7 3.1 1.0 2.2 94 83 >10,000 78 1.2 82 85 >10.000 76 4,700 99 6,000 88 6 10 Melts 470 460 7,500 400 9,500 5 1 0 4,700 1 90 6,000 680 9,000 450 5.600 460 4,500 420 2,800 460 4,800 460 660 Melts 430 Melts 370 - 360 - 0.020 0.015 300f 0.01 Meits 0.0 10 220 0.015 - 0.020 450t 0.040 4601 0.030 0.040 0.020 0.015 0.020 0.035 0.050 0.160 0.075 0.025 0.050 0.040 0.025 0.040 0.065 0.035 0.045 0.080 0.065 0.060 0.035 280 0.060 0.070 1.1 0.9 64 2,800 880 1 75 0.060 0.035 1.0 73 0.9 1.2 3.9 0.1 ().7 1.1 0.1 0.7 0.4 3.0 0.5 . _ 3.0 7.4 0.4 0.7 71 0.8 70 8.7 92 >10.2 97 < 0.1 8 90 1.2 56 46 41 94 48 - 1.1 87 0.7 50 G G G G 2,600 770 3.300 830 2,300 510 1 8,000 550 >20,000 610 100 420 2,400 470 570 4,20() 580 760 900 1,800 320 2,400 320 710 1 5,000 560 2,800 450 k 2,4(~0 780 2,600 630 1 75 0.050 1 75 0.050 1 75 0.050 740 0.0 1 5 320 0.010 330 1.920 400 0.060 250 4.00 400 0. l 40 370 290 0.080 3 1 0 0.020 270 '' 430 0.040 240 0.08 950 0.960 300 0.1 20 550 340 0.030 0.055 0.020 0.045 0.045 0.420 <0.100 0.230 0.120 0.105 0.030 0.125 0.160 <0.200 G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G G E pth Eth ~ ~t'' Eth Eth Eth E Eth

OCR for page 15
lg TABLE 4-1 Classification of Dusts by National Electrical Code (cons I d) Ma%. Ra1e 1gnilion Min. Ma`. o1 TempeIalure Cloud Min. NEC 1~ilion Explo- E%plo$ion Pressure l~nilion Explosion Classincalion Sensi- `~in Pr-~h Pic~6 [`I^~H 1 ~-, ~n~ee`' r^-,~~ ,.;^- ivily Severi1y (psi8) (p~i/~) ~ C) { C) (j) 19.9 32.3 f).2 5.4 1.0 37.] 316 0.] < 0.1 503 of Du~ ~o~m 4~1~ns L~ O) ~odum hydd~ 4conu~s 0.94'; H) Tin, alomized ( 96'{ Sn. 2~ Pb) litanium (99~ li) ~l^m hyd~ (95~ TL ].8~ M) lu~sen, hydm~n mdu~d uranium uranium hydride V~m (~.~ V) Zinc, conden~d (977 Zn, 2~ Pb) . . . ~um, p~d 1mm hyd~ (~s 0~ O) Zirconium byd~de (9].6~) 17 ~ ^Hoys ~d ~mpoun~ ^lum~um-cobd1 ~oy (6~40) 0.1 ^luminum~op~r ~oy (50-50) 0.2 ^~m~_~h~ ( 15~ Li) o. ^~m~um~dum ~oy (Dowmelal) 2.9 ^lum~um-nickel ~oy (58~2) 0.1 Alum~um-sUicon ~loy ( 127 Si) 1.3 C~cium siDcide 0.4 Fe~_e~, me~um c~bon 0.4 - < FeIroti1=ium ( 19~ Ti, 74. 1 * Fe, 0.06~ C) 0.5 8. Peslidde$ Benzelhonium chloride 4.4 Bis (2-hydroxy-5-chlo[ophonyl}- me~ane ~~ 2~ (307 com- busliblc, 10~ inerl) 2, 6 -Di-lerl iary-bulyl-para-cresol Dilhane (zinc elhy~nedilhio- ~ae) - ~e~y~i~ ma~ (Fe~) M_~. ~nd~ 1~l~1~r _~ (~v~) 1 57 (~ ~) dimethyl-2H-1, 3, S- 1~1~, - 9~)5 (~ ~) e, o'-lrithicbis tN, N- d~ethyllhio~rmamide ) 9. lhermoplaslic Resins ~d ~olding ~mpounds G~ L ~ ~ ^ce1~, ~ear (polyfo~dehyde) ~_ Melhyl melhac~late~1hyl acrylele copolymer Melhyl melhac~lale~lhyl ~y=- c-~y~r m~_ bu udiene-acrylonitrde copoly~ .er -~ a~ p~~. m~i~d 1.1 1.5 2.1 213 5.2 0.3 18.0 8.7 ].4 6.5 15.1 14.0 9.2 8.4 1.0 l~nilion Explosion sion Pressurc~ Rise~ Cloud Layer Energy Concenlralion 48 6{) 17 7(1 96 ~1 41 48 < }1 15 1.1 65 1.1 69 3.5 78 0.9 68 1.9 96 4,5 86 4.1 79 2.9 74 5.0 73 1.0 47 1.6 87 2.6 51 1.6 91 0.7 70 2.4 82 1~9 82 2.6 80 1.8 77 1.6 72 2.0 94 2.6 81 1.9 89 1.0 101 85 73 2.7 1.7 1.4 76 0.6 82 1.3(}(, 6.5 (~() 1 .3{14' ~ `~(}0 1 2.t}0() 1,400 6,500 600 200 9,000 9,000 8.500 2,600 3,700 1 0.000 1 0.000 7,500 1 3,000 4,200 1,600 2,200 1.100 2,(~0(1 5.5(){} 9,{}(~{) 6,300 4,500 4.20() 4,()00 6,noo 4,100 1 ,8()0 6,000 ~ ,4 00 3,400 1.500 2 7~) 264' 63(1 13() 8{) 2[) 20 500 69() 20 150 950 930 47() 43U 95() 670 540 45(] 860 370 38(} 57f) 55() 4 ? 4 R(} 280 100 560 140 110 33() 280 230 480 450 29(} 78() {).()(}5 211 ~l.ti()] 43~) (~.t)80 5 1 [) 4).~123 54() 4}.t}60 42{} 1 ~ ~5 20 0.005 4~ ~0 54(} 0.960 1 90 0.005 270 0.060 3~ ~1- 8~ ~10 4~ ~14 48[) 0.080 540 0.080 -- f).ObO 5- ~150 290 0.080 8~ ~4~ 40{) 7.080 4 1 0 ().060 ().~)6f) (~.1~5 [).11 1 18{} 1 50 0.025 1 20 ~2 0.010 0.030 0.035 ().055 0.070 0.020 0.025 0.060 0~20 ~035 0.0 1 5 0.02 ~010 0.020 0.025 0.020 0.100 [< E E E E E E E E E F E E E (o~cu H) 1981 ~c~men~ . ~).{)75 E E ().080 0.190 {).045 0.070 0.06(} 0.060 0.220 0.48 0.04 0.083 0.180 ().10 <0.10 0.020 0.190 0.~0 O.~O 0.130 0.420 0.140 {).02(' {}.~() {).~45 {~.015 / E E E ~1 E E ~ E E E .. _ E E E E E~ E~ E'' F~ . E~ E~ 1~ IS , . .. ~, ~ (~ ~ . ~ ~ . ., (, G GI~ G G ,, ,` G C C G 0.025 0.~5 G G G ~ G G (; G ^ ~ C C

OCR for page 15

OCR for page 15
21 TABLE 4-1 Classification of Dusts by National Electrical Code (cont'd) Type of Dust l- Vinyl chloride-acrylonitrile copolymer, water-emulsion product (6~40) Vinyl chloride-acrylonitrile copolymer, water~mulsion product (33-67) Polyvinyl chloride-dioctyl phthalate mixture (67-33) Vinylidene chloride polymer molding compound Vinyl toluene-acrylonitrile- butadiene copolymer (58-1 9-23) 10. Thermosetting Resins and Molding Compounds . Group 1. Alkyd Resins Alkyd molding compound, mineral filler, not self- extinguishing Group 11. Allyl Resins Allyl alcohol derivative, CR-39, (from dust collector) Allyl alcohol derivative, CR- 1 49-glass fiber mixture (65-35) < Group 111. Amino Resins (Melamine and Urea) Melarnu~e formaldehyde, unfilled laminating type, no plasticizer Urea formaldehyde molding compound, Grade 11, fine Urea formaldehyde-phenol forrnaddehyde molding compound, wood flour filler (group IV. Epoxy Resins Epoxy, no catalyst, modifier, Or additives Epoxy-bisphenol A mixture Group V. I:uran Resins Phenol furfural Group Vl. Phenolic Resins Phenol formaldehyde Phenol formaldehyde, I-step Phenol formaldehyde, 2-step Phenol formaldehyde. . . semlreslnous Phenol formaldehyde molding compound, wood flour filler Phenol formaldehyde. polyalkylene polyamine modified (group Vll. Polyester Resins Polyethylene terephthalate Styrene modified polyester- glass fiber mixture (65-35) Group Vlil. Polyurethane Resins (Isocyanate) Polyurethane loam (tolu.:ne diisocyanate-poly hydroxy with tiuorocarbon blowing agent). no life retardant Polyurethane foam (toluene diisocyanate-polyhydroxy with tiucrocarbon blowing agent), fire retardant Max. Ignition Explo- Explosion Sensi- sion Pressured tivity Severity (PSiB) 3.1 ().6 7.2 2.0 3.6 ().8 9.5 2.2 0.2 < 0.1 5.8 6.7 '0.1 0.2 0.1 0.6 0.5 0.9 12.4 2.7 .~.8 0.5 9.3 3.9 7.9 5.3 1 3.9 4.0 < 0.1 8.9 4.7 1 6.0 2.8 2.9 2.6 2.0 2.6 6.6 9.8 1.7 71 87 65 71 15 106 34 61 89 86 ~6 68 4.0 90 105 92 89 18 94 96 91 84 1.5 84 88 6,000 S30 150 1 2,000 1 ,000 700 3,600 2,000 6.000 1 .5()0 8,SOO 7,000 1 1,000 8.500 200 9,SOO 5,500 5,500 6.000 3.400 3.700 Max. Rate Ignition at Temperature Pressure Riseh Cloud Layer (psi/s) ( OCR for page 15
22 TABLE 4-1 Classification of Dusts by National Electrical Code (cons' d) Max. Rate Ignition Min. Max. of Temperature Cloud Min. Nli;C Ignition limply Explosion Pressure Ignition [:xplosion Classification Sensi- sion Pressureb Riseb Cloud Layer Energy Concentration Type of Dust tivity Severity (psi") (psi/s) (C) (TIC) (J) (oz/cu ft) 1981 Recommended . _ . 11. Special Resins and Molding Compounds Group 1. Cold Molded Resins Petroleum resin (blown asphalt), regular 6.3 2.3 94 4,600 S10 50(}f 0.02S 0.02S G G Group 11. Coumarone-lndene Results Coumarone-inden-, hard 2S.8 S.4 93 11,000 S20 - 0.010 0.01S G G Group 111. Natural Resins Cashew oil, phenolic, hard 6.8 1.8 85 4,000 470 180 0.025 0.02S G G Lignin, hydrolyzed-wood type, fines S.6 2.7 102 S,OOO 450 - 0.020 0.040 G G Rosin, DK 34.4 5.S 87 12,000 390 - 0.010 0.01S G G Shellac 2S.2 1.4 73 3,600 400 - 0.010 0.020 G G Sodium resinate, dry size, grade XXX 2.7 1.8 94 3,600 350 220 0.060 0.03S G G Group IV. Rubber Rubber, crude, hard 4.6 1.6 80 3,800 3SO - O.OSO 0.025 G G Rubber, synthetic, hard, contains33%sulfur 7.0 1.5 93 3,100 320 - 0.030 0.030 G G Rubber, chlorinated - - - - 940 290 ~ R G d Group V. Miscellaneous Resins Alkyl ketone dimer sizing compound, dimer dispersed on silica (50-50) 5.3 2.4 76 6,000 420 160 0.030 0.030 G G Chlorinated phenol (bis- ( 2-hydroxy-5-chlorophenyl) methane) 1.5 0.7 70 2,000 570 - 0.060 0.040 G G Ethylene oxide polymer 6.4 0.9 89 2,000 350 - 0.030 0.030 G G Ethylene-maleic anhydride copolymer 1.0 0.2 51 700 540 - 0.040 0.095 G G Styrene-maleic anhydride copolymer 7.1 4.1 82 9,500 470 490 0.020 0.030 G G Petrin acrylate monomer, crude 10.2 8.7 104 16,000 220 - 0.020 0.04S G G Matcrials are trom Table 3-8A. NtPA Fire Protection Handbook. 14th edition. Data in Table 3-8A was extensively modified by reviewing the following reports ot the U.S. Department of Interior, Bureau of Mines: R1 5753,The Explosibility of Agricultural Dusts; R1 6S16, Explosibility of Metal Powders; R1 5971, Explosibility of Dusts Used in the Plastics Industry; R1 6597, Explosibility of Carbonaceous Dusts; R1 7132, Dust Explosibility of Chemicals, Drugs, Dyes and Pesticides; and R1 7208, Explosibility of Miscellaneous Dusts. The data given tor ignition temperatures, minimum cloud ignition energy, and minimum explosion concentration were the minimum values for the type of sample tested. lathe data given for maximum explosion pressure and maximum rate of pressure rise were those obtained for a single sample of a type tested at a concentration of 0.5 oz/ft3. hAII maximum pressure rates and explosion pressures determined at concentrations of 0.5 oz/ft3. `'Determined by dispersing with an airblast from an 80-in.3 reservoir charged to 1 5-p.s.i.g. pressure (Method A). All other results determined by dispersing with an airblast from a 3-in.3 reservoir charged to a 100-p.s.i.g. pressure (Method B). Method A is related to Method B by a conversion factor of 3.07. '[Ignition sensitivity <0.2 and explosion severity <0.5; constitutes primarily a weak explosion hazard. Gino ignition up to 8.32-J spark, the highest tried. Jlgnition denoted by name; all others not so marked denoted by a glow. KNo ignition up to a concentration of 2 oz/ft3. the highest tried. hl:xplosion severity or ignition sensitivity unknown; dagger indicates classification based on resistivity or best judgement of the panel. 'Guncotton ignition source. JAsterisk indicates a difference of opinion among panelists; classification given is the more stringent tine. kNo ignition. [Material is pyrophoric. :