NIOSH logo and tagline

Immediately Dangerous To Life or Health (IDLH) Values

Original (SCP) IDLH Values

Substance CAS no. Original (SCP) IDLH Values*
Acetaldehyde 75-07-0 10,000 ppm
Acetic acid 64-19-7 1,000 ppm
Acetic anhydride 108-24-7 1,000 ppm
Acetone 67-64-1 20,000 ppm
Acetonitrile 75-05-8 4,000 ppm
Acetylene tetrabromide 79-27-6 10 ppm
Acrolein 107-02-8 5 ppm
Acrylamide 79-06-1 Unknown
Acrylonitrile 107-13-1 500 ppm
Aldrin 309-00-2 100 mg/m3
Allyl alcohol 107-18-6 150 ppm
Allyl chloride 107-05-1 300 ppm
Allyl glycidyl ether 106-92-3 270 ppm
2 Aminopyridine 504-29-0 5 ppm
Ammonia 7664-41-7 500 ppm
Ammonium sulfamate 7773-06-0 5,000 mg/m3
n-Amyl acetate 628-63-7 4,000 ppm
sec-Amyl acetate 626-38-0 9,000 ppm
Aniline 62-53-3 100 ppm
o-Anisidine 90-04-0 50 mg/m3
p-Anisidine 104-94-9 50 mg/m3
Antimony compounds (as Sb) 7440-36-0 80 mg Sb/m3
ANTU 86-88-4 100 mg/m3
Arsenic (inorganic compounds, as As) 7440-38-2 (metal) 100 mg As/m3
Arsine 7784-42-1 6 ppm
Azinphosmethyl 86-50-0 20 mg/m3
Barium (soluble compounds, as Ba) 7440-39-3 1,100 mg Ba/m3
Benzene 71-43-2 3,000 ppm
Benzonitrile
Benzoyl peroxide 94-36-0 7,000 mg/m3
Benzyl chloride 100-44-7 10 ppm
Beryllium compounds (as Be) 7440-41-7 (metal) 10 mg Be/m3
Boron oxide 1303-86-2 N.E.
Boron trifluoride 7637-07-2 100 ppm
Bromine 7726-95-6 10 ppm
Bromine Pentafluoride
Bromoform 75-25-2 Unknown
Butane 106-97-8
1,3-Butadiene 106-99-0 20,000 ppm [LEL]
2-Butanone 78-93-3 3,000 ppm
2-Butoxyethanol 111-76-2 700 ppm
n-Butyl acetate 123-86-4 10,000 ppm
sec-Butyl acetate 105-46-4 10,000 ppm
tert-Butyl acetate 540-88-5 10,000 ppm
n-Butyl alcohol 71-36-3 8,000 ppm
sec-Butyl alcohol 78-92-2 10,000 ppm
tert-Butyl alcohol 75-65-0 8,000 ppm
n-Butylamine 109-73-9 2,000 ppm
tert-Butyl chromate 1189-85-1 30 mg/m3 (as CrO3)
n-Butyl Acrylate 141-32-2
n-Butyl glycidyl ether 2426-08-6 3,500 ppm
n-Butyl mercaptan 109-79-5 2,500 ppm
p-tert-Butyltoluene 98-51-1 1,000 ppm
Cadmium dust (as Cd) 7440-43-9 (metal) 50 mg Cd/m3
Cadmium fume (as Cd) 1306-19-0 (CdO) 9 mg Cd/m3
Calcium arsenate (as As) 7778-44-1 100 mg As/m3
Calcium oxide 1305-78-8 Unknown
Camphor (synthetic) 76-22-2 200 mg/m3
Carbaryl 63-25-2 600 mg/m3
Carbon black 1333-86-4 N.E.
Carbon dioxide 124-38-9 50,000 ppm
Carbon disulfide 75-15-0 500 ppm
Carbon monoxide 630-08-0 1,500 ppm
Carbon tetrachloride 56-23-5 300 ppm
Chlordane 57-74-9 500 mg/m3
Chlorinated camphene 8001-35-2 200 mg/m3
Chlorinated diphenyl oxide n/a Unknown
Chlorine 7782-50-5 30 ppm
Chlorine dioxide 10049-04-4 10 ppm
Chlorine Pentafluoride 13637-63-3
Chlorine trifluoride 7790-91-2 20 ppm
Chloroacetaldehyde 107-20-0 100 ppm
alpha-Chloroacetophenone 532-27-4 100 mg/m3
Chlorobenzene 108-90-7 2,400 ppm
o-Chlorobenzylidene malononitrile 2698-41-1 2 mg/m3
Chlorobromomethane 74-97-5 5,000 ppm
Chlorodiphenyl (42% chlorine) 53469-21-9 10 mg/m3
Chlorodiphenyl (54% chlorine) 11097-69-1 5 mg/m3
Chloroform 67-66-3 1,000 ppm
1-Chloro-1-nitropropane 600-25-9 2,000 ppm
Chloroacetyl Chloride 79-04-9
Chloropicrin 76-06-2 4 ppm
beta-Chloroprene 126-99-8 400 ppm
Chromic acid and chromates 1333-82-0 (CrO3) 30 mg/m3 (as CrO3)
Chromium (II) compounds [as Cr(II)] n/a N.E.
Chromium (III) compounds [as Cr(III)] n/a N.E.
Chromium metal (as Cr) 7440-47-3 N.E.
Coal tar pitch volatiles 65996-93-2 700 mg/m3
Cobalt metal, dust and fume (as Co) 7440-48-4 20 mg Co/m3
Copper (dusts and mists, as Cu) 7440-50-8 N.E.
Copper fume (as Cu) 1317-38-0 (CuO) N.E.
Cotton dust (raw) n/a N.E.
Crag (r) herbicide 136-78-7 5,000 mg/m3
Cresol (o, m, p isomers) 95-48-7 250 ppm
Crotonaldehyde 4170-30-3 400 ppm
Cumene 98-82-8 8,000 ppm
Cyanides (as CN) n/a 50 mg/m3 (as CN)
Cyclohexane 110-82-7 10,000 ppm
Cyclohexanol 108-93-0 3,500 ppm
Cyclohexanone 108-94-1 5,000 ppm
Cyclohexene 110-83-8 10,000 ppm
Cyclopentadiene 542-92-7 2,000 ppm
2,4-D 94-75-7 500 mg/m3
DDT 50-29-3 N.E.
Decaborane 17702-41-9 100 mg/m3
Demeton 8065-48-3 20 mg/m3
Diacetone alcohol 123-42-2 2,100 ppm
Diazomethane 334-88-3 2 ppm
Diborane 19287-45-7 40 ppm
Dibutyl phosphate 107-66-4 125 ppm
Dibutyl phthalate 84-74-2 9,300 mg/m3
o-Dichlorobenzene 95-50-1 1,000 ppm
p-Dichlorobenzene 106-46-7 1,000 ppm
Dichlorodifluoromethane 75-71-8 50,000 ppm
1,3-Dichloro 5,5-dimethylhydantoin 118-52-5 Unknown
1,1-Dichloroethane 75-34-3 4,000 ppm
1,2-Dichloroethylene 540-59-0 4,000 ppm
Dichloroethyl ether 111-44-4 250 ppm
Dichloromonofluoromethane 75-43-4 50,000 ppm
1,1-Dichloro-1-Fluoroethane (HCFC-141b) 1717-00-6
1,1-Dichloro 1-nitroethane 594-72-9 150 ppm
Dichlorotetrafluoroethane 76-14-2 50,000 ppm
Dichlorvos 62-73-7 200 mg/m3
Dieldrin 60-57-1 450 mg/m3
Diethylamine 109-89-7 2,000 ppm
2-Diethylaminoethanol 100-37-8 500 ppm
Difluorodibromomethane 75-61-6 2,500 ppm
Diglycidyl ether 2238-07-5 25 ppm
Diisobutyl ketone 108-83-8 2,000 ppm
Diisopropylamine 108-18-9 1,000 ppm
Diketene
Dimethyl acetamide 127-19-5 400 ppm
Dimethylamine 124-40-3 2,000 ppm
N,N-Dimethylaniline 121-69-7 100 ppm
Dimethyl 1,2-dibromo 2,2-dichlorethyl phosphate 300-76-5 1,800 mg/m3
Dimethylformamide 68-12-2 3,500 ppm
1,1-Dimethylhydrazine 57-14-7 50 ppm
Dimethylphthalate 131-11-3 9,300 mg/m3
Dimethyl sulfate 77-78-1 10 ppm
Dinitrobenzene (o, m, p isomers) 528-29-0 200 mg/m3
Dinitroocresol 534-52-1 5 mg/m3
Dinitrotoluene 25321-14-6 200 mg/m3
Di sec-octyl phthalate 117-81-7 Unknown
Dioxane 123-91-1 2,000 ppm
Diphenyl 92-52-4 300 mg/m3
Dipropylene glycol methyl ether 34590-94-8 Unknown
Endrin 72-20-8 2,000 mg/m3
Epichlorohydrin 106-89-8 250 ppm
EPN 2104-64-5 50 mg/m3
Ethanolamine 141-43-5 1,000 ppm
2-Ethoxyethanol 110-80-5 6,000 ppm
2-Ethoxyethyl acetate 111-15-9 2,500 ppm
Ethyl acetate 141-78-6 10,000 ppm
Ethyl acrylate 140-88-5 2,000 ppm
Ethyl alcohol 64-17-5 15,000 ppm
Ethylamine 75-04-7 4,000 ppm
Ethyl benzene 100-41-4 2,000 ppm
Ethyl bromide 74-96-4 3,500 ppm
Ethyl butyl ketone 106-35-4 3,000 ppm
Ethyl chloride 75-00-3 20,000 ppm
Ethylene chlorohydrin 107-07-3 10 ppm
Ethylenediamine 107-15-3 2,000 ppm
Ethylene dibromide 106-93-4 400 ppm
Ethylene dichloride 107-06-2 1,000 ppm
Ethylene glycol dinitrate 628-96-6 500 mg/m3
Ethyleneimine 151-56-4 100 ppm
Ethylene oxide 75-21-8 800 ppm
Ethyl ether 60-29-7 19,000 ppm [LEL]
Ethyl formate 109-94-4 8,000 ppm
Ethyl mercaptan 75-08-1 2,500 ppm
N-Ethylmorpholine 100-74-3 2,000 ppm
Ethyl silicate 78-10-4 1,000 ppm
Ferbam 14484-64-1 N.E.
Ferrovanadium dust 12604-58-9 N.E.
Fluorides (as F) n/a 500 mg F/m3
Fluorine 7782-41-4 25 ppm
Fluorotrichloromethane 75-69-4 10,000 ppm
Formaldehyde 50-00-0 30 ppm
Formic acid 64-18-6 30 ppm
Furan 203-727-3
Furfural 98-01-1 250 ppm
Furfuryl alcohol 98-00-0 250 ppm
Glycidol 556-52-5 500 ppm
Graphite (natural) 7782-42-5 N.E.
Hafnium compounds (as Hf) 7440-58-6 Unknown
Heptachlor 76-44-8 700 mg/m3
n-Heptane 142-82-5 5,000 ppm
Hexachloroethane 67-72-1 300 ppm
Hexachloronaphthalene 1335-87-1 2 mg/m3
Hexafluoroactone 684-16-2
n-Hexane 110-54-3 5,000 ppm
2-Hexanone 591-78-6 5,000 ppm
Hexone 108-10-1 3,000 ppm
sec Hexyl acetate 108-84-9 4,000 ppm
Hydrazine 302-01-2 80 ppm
Hydrogen bromide 10035-10-6 50 ppm
Hydrogen chloride 7647-01-0 100 ppm
Hydrogen cyanide 74-90-8 50 ppm
Hydrogen fluoride (as F) 7664-39-3 30 ppm
Hydrogen peroxide 7722-84-1 75 ppm
Hydrogen selenide (as Se) 7783-07-5 2 ppm
Hydrogen sulfide 7783-06-4 300 ppm
Hydroquinone 123-31-9 Unknown
Iodine 7553-56-2 10 ppm
Iron oxide dust and fume (as Fe) 1309-37-1 N.E.
Iron Pentacarbonyl 13463-40-6
Isoamyl acetate 123-92-2 3,000 ppm
Isoamyl alcohol (primary and secondary) 123-51-3 10,000 ppm
Isobutyl acetate 110-19-0 7,500 ppm
Isobutyl alcohol 78-83-1 8,000 ppm
Isophorone 78-59-1 800 ppm
Isopropyl acetate 108-21-4 16,000 ppm
Isopropyl alcohol 67-63-0 12,000 ppm
Isopropylamine 75-31-0 4,000 ppm
Isopropyl ether 108-20-3 10,000 ppm
Isopropyl glycidyl ether 4016-14-2 1,000 ppm
Ketene 463-51-4 Unknown
Lead compounds (as Pb) 7439-92-1 700 mg Pb/m3
Lindane 58-89-9 1,000 mg/m3
Lithium hydride 7580-67-8 55 mg/m3
L.P.G. 68476-85-7 19,000 ppm [LEL]
Magnesium oxide fume 1309-48-4 N.E.
Malathion 121-75-5 5,000 mg/m3
Maleic anhydride 108-31-6 Unknown
Manganese compounds (as Mn) 7439-96-5 (metal) N.E.
Mercury compounds [except (organo) alkyls, as Hg] 7439-97-6 (metal) 28 mg Hg/m3
Mercury (organo) alkyl compounds(as Hg) n/a 10 mg Hg/m3
Mesityl oxide 141-79-7 5,000 ppm
Methoxychlor 72-43-5 N.E.
Methyl acetate 79-20-9 10,000 ppm
Methyl acetylene 74-99-7 15,000 ppm [LEL]
Methyl acetylenepropadiene mixture 59355-75-8 15,000 ppm
Methyl acrylate 96-33-3 1,000 ppm
Methylal 109-87-5 15,000 ppm [LEL]
Methyl alcohol 67-56-1 25,000 ppm
Methylamine 74-89-5 100 ppm
Methyl (namyl) ketone 110-43-0 4,000 ppm
Methyl bromide 74-83-9 2,000 ppm
Methyl Cellosolve (r) 109-86-4 2,000 ppm
Methyl Cellosolve (r) acetate 110-49-6 4,000 ppm
Methyl chloride 74-87-3 10,000 ppm
Methyl chloroform 71-55-6 1,000 ppm
Methylcyclohexane 108-87-2 10,000 ppm
Methylcyclohexanol 25639-42-3 10,000 ppm
o-Methylcyclohexanone 583-60-8 2,500 ppm
Methylene bisphenyl isocyanate 101-68-8 100 mg/m3
Methylene chloride 75-09-2 5,000 ppm
Methyl formate 107-31-3 5,000 ppm
5-Methyl 3-heptanone 541-85-5 3,000 ppm
Methyl hydrazine 60-34-4 50 ppm
Methyl iodide 74-88-4 800 ppm
Methyl isobutyl carbinol 108-11-2 2,000 ppm
Methyl isocyanate 624-83-9 20 ppm
Methyl mercaptan 74-93-1 400 ppm
Methyl methacrylate 80-62-6 4,000 ppm
Methyl styrene 98-83-9 5,000 ppm
Mica 12001-26-2 N.E.
Molybdenum (insoluble compounds, as Mo) n/a N.E.
Molybdenum (soluble compounds, as Mo) n/a N.E.
Monomethyl aniline 100-61-8 100 ppm
Morpholine 110-91-8 8,000 ppm
Naphtha (coal tar) 8030-30-6 10,000 ppm [LEL]
Naphthalene 91-20-3 500 ppm
Nickel carbonyl (as Ni) 13463-39-3 7 ppm
Nickel metal and other compounds (as Ni) 7440-02-0 (Metal) N.E.
Nicotine 54-11-5 35 mg/m3
Nitric acid 7697-37-2 100 ppm
Nitric oxide 10102-43-9 100 ppm
p-Nitroaniline 100-01-6 300 mg/m3
Nitrobenzene 98-95-3 200 ppm
p-Nitrochlorobenzene 100-00-5 1,000 mg/m3
Nitroethane 79-24-3 1,000 ppm
Nitrogen dioxide 10102-44-0 50 ppm
Nitrogen trifluoride 7783-54-2 2,000 ppm
Nitroglycerine 55-63-0 500 mg/m3
Nitromethane 75-52-5 1,000 ppm
1-Nitropropane 108-03-2 2,300 ppm
2-Nitropropane 79-46-9 2,300 ppm
Nitrotoluene (o, m, p isomers) 88-72-2 200 ppm
Octachloronaphthalene 2234-13-1 Unknown
Octane 111-65-9 5,000 ppm
Oil mist (mineral) 8012-95-1 N.E.
Osmium tetroxide (as Os) 20816-12-0 1 mg Os/m3
Oxalic acid 144-62-7 500 mg/m3
Oxygen difluoride 7783-41-7 0.5 ppm
Ozone 10028-15-6 10 ppm
Paraquat 1910-42-5 1.5 mg/m3
Parathion 56-38-2 20 mg/m3
Pentaborane 19624-22-7 3 ppm
Pentachloronaphthalene 1321-64-8 Unknown
Pentachlorophenol 87-86-5 150 mg/m3
n-Pentane 109-66-0 15,000 ppm [LEL]
2-Pentanone 107-87-9 5,000 ppm
Perchloromethyl mercaptan 594-42-3 10 ppm
Perchloryl fluoride 7616-94-6 385 ppm
Petroleum distillates (naphtha) 8002-05-9 10,000 ppm
Phenol 108-95-2 250 ppm
p-Phenylene diamine 106-50-3 Unknown
Phenyl ether (vapor) 101-84-8 N.E.
Phenyl etherbiphenyl mixture (vapor) 8004-13-5 N.E.
Phenyl glycidyl ether 122-60-1 Unknown
Phenylhydrazine 100-63-0 295 ppm
Phosdrin 7786-34-7 4 ppm
Phosgene 75-44-5 2 ppm
Phosphine 7803-51-2 200 ppm
Phosphoric acid 7664-38-2 10,000 mg/m3
Phosphorus (yellow) 7723-14-0 N.E.
Phosphorus pentachloride 10026-13-8 200 mg/m3
Phosphorus pentasulfide 1314-80-3 750 mg/m3
Phosphorus trichloride 7719-12-2 50 ppm
Phthalic anhydride 85-44-9 10,000 mg/m3
Picric acid 88-89-1 100 mg/m3
Pindone 83-26-1 200 mg/m3
Platinum (soluble salts, as Pt) n/a N.E.
Portland cement 65997-15-1 N.E.
Propane 74-98-6 20,000 ppm [LEL]
n-Propyl acetate 109-60-4 8,000 ppm
n-Propyl alcohol 71-23-8 4,000 ppm
Propylene dichloride 78-87-5 2,000 ppm
Propylene imine 75-55-8 500 ppm
Propylene oxide 75-56-9 2,000 ppm
n-Propyl nitrate 627-13-4 2,000 ppm
Pyrethrum 8003-34-7 5,000 mg/m3
Pyridine 110-86-1 3,600 ppm
Quinone 106-51-4 300 mg/m3
Rhodium (metal fume and insoluble compounds, as Rh) 7440-16-6 (metal) N.E.
Rhodium (soluble compounds, as Rh) n/a N.E.
Ronnel 299-84-3 5,000 mg/m3
Rotenone 83-79-4 Unknown
Selenium compounds (as Se) 7782-49-2 Unknown
Selenium hexafluoride 7783-79-1 5 ppm
Silica, amorphous 7631-86-9 N.E.
Silica, crystalline (respirable dust) 14808-60-7 N.E.
cristobalite/tridymite 14808-60-7
quartz/tripoli 14808-60-7
Silver (metal dust and soluble compounds, as Ag) 7440-22-4 (metal) N.E.
Soapstone n/a N.E.
Sodium fluoroacetate 62-74-8 5 mg/m3
Sodium hydroxide 1310-73-2 250 mg/m3
Stibine 7803-52-3 40 ppm
Stoddard solvent 8052-41-3 29,500 mg/m3
Strychnine 57-24-9 3 mg/m3
Styrene 100-42-5 5,000 ppm
Sulfur dioxide 7446-09-5 100 ppm
Sulfuric acid 7664-93-9 80 mg/m3
Sulfur monochloride 10025-67-9 10 ppm
Sulfur pentafluoride 5714-22-7 1 ppm
Sulfuryl fluoride 2699-79-8 1,000 ppm
2,4,5-T 93-76-5 Unknown
Talc 14807-96-6 N.E.
Tantalum (metal and oxide dust, as Ta) 7440-25-7 (metal) N.E.
TEDP 3689-24-5 35 mg/m3
Tellurium compounds (as Te) 13494-80-9 N.E.
Tellurium hexafluoride 7783-80-4 1 ppm
TEPP 107-49-3 10 mg/m3
Terphenyl (o, m, p isomers) 84-15-1 Unknown
1,1,1,2-Tetrachloro 2,2-difluoroethane 76-11-9 15,000 ppm
1,1,2,2-Tetrachloro 1,2-difluoroethane 76-12-0 15,000 ppm
1,1,2,2-Tetrachloroethane 79-34-5 150 ppm
Tetrachloroethylene 127-18-4 500 ppm
Tetrachloronaphthalene 1335-88-2 Unknown
Tetraethyl lead (as Pb) 78-00-2 40 mg Pb/m3
Tetrahydrofuran 109-99-9 20,000 ppm [LEL]
Tetramethyl lead (as Pb) 75-74-1 40 mg Pb/m3
Tetramethyl succinonitrile 3333-52-6 5 ppm
Tetranitromethane 509-14-8 5 ppm
Tetryl 479-45-8 N.E.
Thallium (soluble compounds, as Tl) n/a 20 mg Tl/m3
Thiram 137-26-8 1,500 mg/m3
Tin (inorganic compounds, as Sn) n/a 400 mg Sn/m3
Tin (organic compounds, as Sn) n/a Unknown
Titanium dioxide 13463-67-7 N.E.
Toluene 108-88-3 2,000 ppm
Toluene 2,4-diisocyanate 584-84-9 10 ppm
o-Toluidine 95-53-4 100 ppm
Tributyl phosphate 126-73-8 125 ppm
1,1,2-Trichloroethane 79-00-5 500 ppm
Trichloroethylene 79-01-6 1,000 ppm
Trichloronaphthalene 1321-65-9 Unknown
1,2,3-Trichloropropane 96-18-4 1,000 ppm
1,1,2-Trichloro 1,2,2-trifluoroethane 76-13-1 4,500 ppm
Triethylamine 121-44-8 1,000 ppm
Trifluorobromomethane 75-63-8 50,000 ppm
2,4,6-Trinitrotoluene 118-96-7 1,000 mg/m3
Triorthocresyl phosphate 78-30-8 40 mg/m3
Triphenyl phosphate 115-86-6 N.E.
Turpentine 8006-64-2 1,500 ppm
Uranium (insoluble compounds, as U) 7440-61-1 (metal) 30 mg U/m3
Uranium (soluble compounds, as U) n/a 20 mg U/m3
Vanadium dust 1314-62-1 70 mg/m3 (as V2O5)
Vanadium fume 1314-62-1 70 mg/m3 (as V2O5)
Vinyl toluene 25013-15-4 (inhibited) 5,000 ppm
Warfarin 81-81-2 350 mg/m3
Xylene (o, m, p isomers) 95-47-6 1,000 ppm
Xylidine 1300-73-8 150 ppm
Yttrium compounds (as Y) 7440-65-5 N.E.
Zinc chloride fume 7646-85-7 4,800 mg/m3
Zinc oxide 1314-13-2 2,500 mg/m3
Zirconium compounds (as Zr) 7440-67-7 (Metal) 500 mg Zr/m3

Notes