Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to site content Skip directly to page options
CDC Home

Chemical Listing and Documentation of Revised IDLH Values (as of 3/1/95)

May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
SubstanceOriginal IDLH ValueRevised IDLH Value
Acetaldehyde 10,000 ppm2,000 ppm
Acetic acid1,000 ppm50 ppm
Acetic anhydride1,000 ppm200 ppm
Acetone20,000 ppm2,500 ppm [LEL]
Acetonitrile4,000 ppm500 ppm
Acetylene tetrabromide10 ppm8 ppm
Acrolein5 ppm2 ppm
AcrylamideUnknown60 mg/m3
Acrylonitrile500 ppm85 ppm
Aldrin100 mg/m325 mg/m3
Allyl alcohol150 ppm20 ppm
Allyl chloride300 ppm250 ppm
Allyl glycidyl ether270 ppm50 ppm
2 Aminopyridine5 ppm5 ppm [Unch]
Ammonia500 ppm300 ppm
Ammonium sulfamate5,000 mg/m31,500 mg/m3
n-Amyl acetate4,000 ppm1,000 ppm
sec-Amyl acetate9,000 ppm1,000 ppm
Aniline100 ppm100 ppm [Unch]
o-Anisidine50 mg/m350 mg/m3 [Unch]
p-Anisidine50 mg/m350 mg/m3 [Unch]
Antimony compounds (as Sb)80 mg Sb/m350 mg Sb/m3
ANTU100 mg/m3100 mg/m3 [Unch]
Arsenic (inorganic compounds, as As)100 mg As/m35 mg As/m3
Arsine6 ppm3 ppm
Azinphosmethyl20 mg/m310 mg/m3
Barium (soluble compounds, as Ba)1,100 mg Ba/m350 mg Ba/m3
Benzene3,000 ppm500 ppm
Benzoyl peroxide7,000 mg/m31,500 mg/m3
Benzyl chloride10 ppm10 ppm [Unch]
Beryllium compounds (as Be)10 mg Be/m34 mg Be/m3
Boron oxideN.E.2,000 mg/m3
Boron trifluoride100 ppm25 ppm
Bromine10 ppm3 ppm
BromoformUnknown850 ppm
1,3-Butadiene20,000 ppm [LEL]2,000 ppm [LEL]
2-Butanone3,000 ppm3,000 ppm [Unch]
2-Butoxyethanol700 ppm700 ppm [Unch]
n-Butyl acetate10,000 ppm1,700 ppm [LEL]
sec-Butyl acetate10,000 ppm1,700 ppm [LEL]
tert-Butyl acetate10,000 ppm1,500 ppm [LEL]
n-Butyl alcohol8,000 ppm1,400 ppm [LEL]
sec-Butyl alcohol10,000 ppm2,000 ppm
tert-Butyl alcohol8,000 ppm1,600 ppm
n-Butylamine2,000 ppm300 ppm
tert-Butyl chromate30 mg/m3 (as CrO3)15 mg Cr(VI)/m3
n-Butyl glycidyl ether3,500 ppm250 ppm
n-Butyl mercaptan2,500 ppm500 ppm
p-tert-Butyltoluene1,000 ppm100 ppm
Cadmium dust (as Cd)50 mg Cd/m39 mg Cd/m3
Cadmium fume (as Cd)9 mg Cd/m39 mg Cd/m3[Unc h]
Calcium arsenate (as As)100 mg As/m35 mg As/m3
Calcium oxideUnknown25 mg/m3
Camphor (synthetic)200 mg/m3200 mg/m3 [Unch]
Carbaryl600 mg/m3100 mg/m3
Carbon blackN.E.1,750 mg/m3
Carbon dioxide50,000 ppm40,000 ppm
Carbon disulfide500 ppm500 ppm [Unch]
Carbon monoxide1,500 ppm1,200 ppm
Carbon tetrachloride300 ppm200 ppm
Chlordane500 mg/m3100 mg/m3
Chlorinated camphene200 mg/m3200 mg/m3 [Unch]
Chlorinated diphenyl oxideUnknown5 mg/m3
Chlorine30 ppm10 ppm
Chlorine dioxide10 ppm5 ppm
Chlorine trifluoride20 ppm20 ppm [Unch]
Chloroacetaldehyde100 ppm45 ppm
alpha-Chloroacetophenone100 mg/m315 mg/m3
Chlorobenzene2,400 ppm1,000 ppm
o-Chlorobenzylidene malononitrile2 mg/m32 mg/m3 [Unch]
Chlorobromomethane5,000 ppm2,000 ppm
Chlorodiphenyl (42% chlorine)10 mg/m35 mg/m3
Chlorodiphenyl (54% chlorine)5 mg/m35 mg/m3 [Unch]
Chloroform1,000 ppm500 ppm
1-Chloro-1-nitropropane2,000 ppm100 ppm
Chloropicrin4 ppm2 ppm
beta-Chloroprene400 ppm300 ppm
Chromic acid and chromates30 mg/m3 (as CrO3)15 mg Cr(VI)/m3
Chromium (II) compounds [as Cr(II)]N.E.250 mg Cr(II)/m3
Chromium (III) compounds [as Cr(III)]N.E.25 mg Cr(III)/m3
Chromium metal (as Cr)N.E.250 mg Cr/m3
Coal tar pitch volatiles700 mg/m380 mg/m3
Cobalt metal, dust and fume (as Co)20 mg Co/m320 mg Co/m3 [Unch]
Copper (dusts and mists, as Cu)N.E.100 mg Cu/m3
Copper fume (as Cu)N.E.100 mg Cu/m3
Cotton dust (raw)N.E.100 mg/m3
Crag (r) herbicide 5,000 mg/m3500 mg/m3
Cresol (o, m, p isomers)250 ppm250 ppm [Unch]
Crotonaldehyde400 ppm50 ppm
Cumene8,000 ppm900 ppm [LEL]
Cyanides (as CN)50 mg/m3 (as CN)25 mg/m3 (as CN)
Cyclohexane10,000 ppm1,300 ppm [LEL]
Cyclohexanol3,500 ppm400 ppm
Cyclohexanone5,000 ppm700 ppm
Cyclohexene10,000 ppm2,000 ppm
Cyclopentadiene2,000 ppm750 ppm
2,4-D500 mg/m3100 mg/m3
DDTN.E.500 mg/m3
Decaborane100 mg/m315 mg/m3
Demeton20 mg/m310 mg/m3
Diacetone alcohol2,100 ppm1,800 ppm [LEL]
Diazomethane2 ppm2 ppm [Unch]
Diborane40 ppm15 ppm
Dibutyl phosphate125 ppm30 ppm
Dibutyl phthalate9,300 mg/m34,000 mg/m3
o-Dichlorobenzene1,000 ppm200 ppm
p-Dichlorobenzene1,000 ppm150 ppm
Dichlorodifluoromethane50,000 ppm15,000 ppm
1,3-Dichloro 5,5-dimethylhydantoinUnknown5 mg/m3
1,1-Dichloroethane4,000 ppm3,000 ppm
1,2-Dichloroethylene4,000 ppm1,000 ppm
Dichloroethyl ether250 ppm100 ppm
Dichloromonofluoromethane50,000 ppm5,000 ppm
1,1-Dichloro 1-nitroethane150 ppm25 ppm
Dichlorotetrafluoroethane50,000 ppm15,000 ppm
Dichlorvos200 mg/m3100 mg/m3
Dieldrin450 mg/m350 mg/m3
Diethylamine2,000 ppm200 ppm
2-Diethylaminoethanol500 ppm100 ppm
Difluorodibromomethane2,500 ppm2,000 ppm
Diglycidyl ether25 ppm10 ppm
Diisobutyl ketone2,000 ppm500 ppm
Diisopropylamine1,000 ppm200 ppm
Dimethyl acetamide400 ppm300 ppm
Dimethylamine2,000 ppm500 ppm
N,N-Dimethylaniline100 ppm100 ppm [Unch]
Dimethyl 1,2-dibromo 2,2-dichlorethyl phosphate1,800 mg/m3200 mg/m3
Dimethylformamide3,500 ppm500 ppm
1,1-Dimethylhydrazine50 ppm15 ppm
Dimethylphthalate9,300 mg/m32,000 mg/m3
Dimethyl sulfate10 ppm7 ppm
Dinitrobenzene (o, m, p isomers)200 mg/m350 mg/m3
Dinitroocresol5 mg/m35 mg/m3 [Unch]
Dinitrotoluene200 mg/m350 mg/m3
Di sec-octyl phthalateUnknown5,000 mg/m3
Dioxane2,000 ppm500 ppm
Diphenyl300 mg/m3100 mg/m3
Dipropylene glycol methyl etherUnknown600 ppm
Endrin2,000 mg/m32 mg/m3
Epichlorohydrin250 ppm75 ppm
EPN50 mg/m35 mg/m3
Ethanolamine1,000 ppm30 ppm
2-Ethoxyethanol6,000 ppm500 ppm
2-Ethoxyethyl acetate2,500 ppm500 ppm
Ethyl acetate10,000 ppm2,000 ppm [LEL]
Ethyl acrylate2,000 ppm300 ppm
Ethyl alcohol15,000 ppm3,300 ppm [LEL]
Ethylamine4,000 ppm600 ppm
Ethyl benzene2,000 ppm800 ppm [LEL]
Ethyl bromide3,500 ppm2,000 ppm
Ethyl butyl ketone3,000 ppm1,000 ppm
Ethyl chloride20,000 ppm3,800 ppm [LEL]
Ethylene chlorohydrin10 ppm7 ppm
Ethylenediamine2,000 ppm1,000 ppm
Ethylene dibromide400 ppm100 ppm
Ethylene dichloride1,000 ppm50 ppm
Ethylene glycol dinitrate500 mg/m375 mg/m3
Ethyleneimine100 ppm100 ppm [Unch]
Ethylene oxide800 ppm800 ppm [Unch]
Ethyl ether19,000 ppm [LEL]1,900 ppm [LEL]
Ethyl formate8,000 ppm1,500 ppm
Ethyl mercaptan2,500 ppm500 ppm
N-Ethylmorpholine2,000 ppm100 ppm
Ethyl silicate1,000 ppm700 ppm
FerbamN.E.800 mg/m3
Ferrovanadium dustN.E.500 mg/m3
Fluorides (as F)500 mg F/m3250 mg F/m3
Fluorine25 ppm25 ppm [Unch]
Fluorotrichloromethane10,000 ppm2,000 ppm
Formaldehyde30 ppm20 ppm
Formic acid30 ppm30 ppm [Unch]
Furfural250 ppm100 ppm
Furfuryl alcohol250 ppm75 ppm
Glycidol500 ppm150 ppm
Graphite (natural)N.E.1,250 mg/m3
Hafnium compounds (as Hf)Unknown50 mg Hf/m3
Heptachlor700 mg/m335 mg/m3
n-Heptane5,000 ppm750 ppm
Hexachloroethane300 ppm300 ppm [Unch]
Hexachloronaphthalene2 mg/m32 mg/m3 [Unch]
n-Hexane5,000 ppm1,100 ppm [LEL]
2-Hexanone5,000 ppm1,600 ppm
Hexone3,000 ppm500 ppm
sec Hexyl acetate4,000 ppm500 ppm
Hydrazine80 ppm50 ppm
Hydrogen bromide50 ppm30 ppm
Hydrogen chloride100 ppm50 ppm
Hydrogen cyanide50 ppm50 ppm [Unch]
Hydrogen fluoride (as F)30 ppm30 ppm [Unch]
Hydrogen peroxide75 ppm75 ppm [Unch]
Hydrogen selenide (as Se)2 ppm1 ppm
Hydrogen sulfide300 ppm100 ppm
HydroquinoneUnknown50 mg/m3
Iodine10 ppm2 ppm
Iron oxide dust and fume (as Fe)N.E.2,500 mg Fe/m3
Isoamyl acetate3,000 ppm1,000 ppm
Isoamyl alcohol (primary and secondary)10,000 ppm500 ppm
Isobutyl acetate7,500 ppm1,300 ppm [LEL]
Isobutyl alcohol8,000 ppm1,600 ppm
Isophorone800 ppm200 ppm
Isopropyl acetate16,000 ppm1,800 ppm
Isopropyl alcohol12,000 ppm2,000 ppm [LEL]
Isopropylamine4,000 ppm750 ppm
Isopropyl ether10,000 ppm1,400 ppm [LEL]
Isopropyl glycidyl ether1,000 ppm400 ppm
KeteneUnknown5 ppm
Lead compounds (as Pb)700 mg Pb/m3100 mg Pb/m3
Lindane1,000 mg/m350 mg/m3
Lithium hydride55 mg/m30.5 mg/m3
L.P.G.19,000 ppm [LEL]2,000 ppm [LEL]
Magnesium oxide fumeN.E.750 mg/m3
Malathion5,000 mg/m3250 mg/m3
Maleic anhydrideUnknown10 mg/m3
Manganese compounds (as Mn)N.E.500 mg Mn/m3
Mercury compounds [except (organo) alkyls, as Hg]28 mg Hg/m310 mg Hg/m3
Mercury (organo) alkyl compounds(as Hg)10 mg Hg/m32 mg Hg/m3
Mesityl oxide5,000 ppm1,400 ppm [LEL]
MethoxychlorN.E.5,000 mg/m3
Methyl acetate10,000 ppm3,100 ppm [LEL]
Methyl acetylene15,000 ppm [LEL]1,700 ppm [LEL]
Methyl acetylenepropadiene mixture15,000 ppm3,400 ppm [LEL]
Methyl acrylate1,000 ppm250 ppm
Methylal15,000 ppm [LEL]2,200 ppm [LEL]
Methyl alcohol25,000 ppm6,000 ppm
Methylamine100 ppm100 ppm [Unch]
Methyl (namyl) ketone4,000 ppm800 ppm
Methyl bromide2,000 ppm250 ppm
Methyl Cellosolve (r)2,000 ppm200 ppm
Methyl Cellosolve (r) acetate4,000 ppm200 ppm
Methyl chloride10,000 ppm2,000 ppm
Methyl chloroform1,000 ppm700 ppm
Methylcyclohexane10,000 ppm1,200 ppm [LEL]
Methylcyclohexanol10,000 ppm500 ppm
o-Methylcyclohexanone2,500 ppm600 ppm
Methylene bisphenyl isocyanate100 mg/m375 mg/m3
Methylene chloride5,000 ppm2,300 ppm
Methyl formate5,000 ppm4,500 ppm
5-Methyl 3-heptanone3,000 ppm100 ppm
Methyl hydrazine50 ppm20 ppm
Methyl iodide800 ppm100 ppm
Methyl isobutyl carbinol2,000 ppm400 ppm
Methyl isocyanate20 ppm3 ppm
Methyl mercaptan400 ppm150 ppm
Methyl methacrylate4,000 ppm1,000 ppm
Methyl styrene5,000 ppm700 ppm
MicaN.E.1,500 mg/m3
Molybdenum (insoluble compounds, as Mo)N.E.5,000 mg Mo/m3
Molybdenum (soluble compounds, as Mo)N.E.1,000 mg Mo/m3
Monomethyl aniline100 ppm100 ppm [Unch]
Morpholine8,000 ppm1,400 ppm [LEL]
Naphtha (coal tar)10,000 ppm [LEL]1,000 ppm [LEL]
Naphthalene500 ppm250 ppm
Nickel carbonyl (as Ni)7 ppm2 ppm
Nickel metal and other compounds (as Ni)N.E.10 mg Ni/m3
Nicotine35 mg/m35 mg/m3
Nitric acid100 ppm25 ppm
Nitric oxide100 ppm100 ppm [Unch]
p-Nitroaniline300 mg/m3300 mg/m3 [Unch]
Nitrobenzene200 ppm200 ppm [Unch]
p-Nitrochlorobenzene1,000 mg/m3100 mg/m3
Nitroethane1,000 ppm1,000 ppm [Unch]
Nitrogen dioxide50 ppm20 ppm
Nitrogen trifluoride2,000 ppm1,000 ppm
Nitroglycerine500 mg/m375 mg/m3
Nitromethane1,000 ppm750 ppm
1-Nitropropane2,300 ppm1,000 ppm
2-Nitropropane2,300 ppm100 ppm
Nitrotoluene (o, m, p isomers)200 ppm200 ppm [Unch]
OctachloronaphthaleneUnknownUnknown [Unch]
Octane5,000 ppm1,000 ppm [LEL]
Oil mist (mineral)N.E.2,500 mg/m3
Osmium tetroxide (as Os)1 mg Os/m31 mg Os/m3 [Unch]
Oxalic acid500 mg/m3500 mg/m3 [Unch]
Oxygen difluoride0.5 ppm0.5 ppm [Unch]
Ozone10 ppm5 ppm
Paraquat1.5 mg/m31 mg/m3
Parathion20 mg/m310 mg/m3
Pentaborane3 ppm1 ppm
PentachloronaphthaleneUnknownUnknown [Unch]
Pentachlorophenol150 mg/m32.5 mg/m3
n-Pentane15,000 ppm [LEL]1,500 ppm [LEL]
2-Pentanone5,000 ppm1,500 ppm
Perchloromethyl mercaptan10 ppm10 ppm [Unch]
Perchloryl fluoride385 ppm100 ppm
Petroleum distillates (naphtha)10,000 ppm1,100 ppm [LEL]
Phenol250 ppm250 ppm [Unch]
p-Phenylene diamineUnknown25 mg/m3
Phenyl ether (vapor)N.E.100 ppm
Phenyl etherbiphenyl mixture (vapor)N.E.10 ppm
Phenyl glycidyl etherUnknown100 ppm
Phenylhydrazine295 ppm15 ppm
Phosdrin4 ppm4 ppm [Unch]
Phosgene2 ppm2 ppm [Unch]
Phosphine200 ppm50 ppm
Phosphoric acid10,000 mg/m31,000 mg/m3
Phosphorus (yellow)N.E.5 mg/m3
Phosphorus pentachloride200 mg/m370 mg/m3
Phosphorus pentasulfide750 mg/m3250 mg/m3
Phosphorus trichloride50 ppm25 ppm
Phthalic anhydride10,000 mg/m360 mg/m3
Picric acid100 mg/m375 mg/m3
Pindone200 mg/m3100 mg/m3
Platinum (soluble salts, as Pt)N.E.4 mg Pt/m3
Portland cementN.E.5,000 mg/m3
Propane20,000 ppm [LEL]2,100 ppm [LEL]
n-Propyl acetate8,000 ppm1,700 ppm
n-Propyl alcohol4,000 ppm800 ppm
Propylene dichloride2,000 ppm400 ppm
Propylene imine500 ppm100 ppm
Propylene oxide2,000 ppm400 ppm
n-Propyl nitrate2,000 ppm500 ppm
Pyrethrum5,000 mg/m35,000 mg/m3 [Unch]
Pyridine3,600 ppm1,000 ppm
Quinone300 mg/m3100 mg/m3
Rhodium (metal fume and insoluble compounds, as Rh)N.E.100 mg Rh/m3
Rhodium (soluble compounds, as Rh)N.E.2 mg Rh/m3
Ronnel5,000 mg/m3300 mg/m3
RotenoneUnknown2,500 mg/m3
Selenium compounds (as Se)Unknown1 mg Se/m3
Selenium hexafluoride5 ppm2 ppm
Silica, amorphousN.E.3,000 mg/m3
Silica, crystalline (respirable dust)N.E.
cristobalite/tridymite:25 mg/m3
quartz/tripoli:50 mg/m3
Silver (metal dust and soluble compounds, as Ag)N.E.10 mg Ag/m3
SoapstoneN.E.3,000 mg/m3
Sodium fluoroacetate5 mg/m32.5 mg/m3
Sodium hydroxide250 mg/m310 mg/m3
Stibine40 ppm5 ppm
Stoddard solvent29,500 mg/m320,000 mg/m3
Strychnine3 mg/m33 mg/m3 [Unch]
Styrene5,000 ppm700 ppm
Sulfur dioxide100 ppm100 ppm [Unch]
Sulfuric acid80 mg/m315 mg/m3
Sulfur monochloride10 ppm5 ppm
Sulfur pentafluoride1 ppm1 ppm [Unch]
Sulfuryl fluoride1,000 ppm200 ppm
2,4,5-TUnknown250 mg/m3
TalcN.E.1,000 mg/m3
Tantalum (metal and oxide dust, as Ta)N.E.2,500 mg Ta/m3
TEDP35 mg/m310 mg/m3
Tellurium compounds (as Te)N.E.25 mg Te/m3
Tellurium hexafluoride1 ppm1 ppm [Unch]
TEPP10 mg/m35 mg/m3
Terphenyl (o, m, p isomers)Unknown500 mg/m3
1,1,1,2-Tetrachloro 2,2-difluoroethane 15,000 ppm2,000 ppm
1,1,2,2-Tetrachloro 1,2-difluoroethane15,000 ppm2,000 ppm
1,1,2,2-Tetrachloroethane150 ppm100 ppm
Tetrachloroethylene500 ppm150 ppm
TetrachloronaphthaleneUnknownUnknown [Unch]
Tetraethyl lead (as Pb)40 mg Pb/m340 mg Pb/m3 [Unch]
Tetrahydrofuran20,000 ppm [LEL]2,000 ppm [LEL]
Tetramethyl lead (as Pb)40 mg Pb/m340 mg Pb/m3 [Unch]
Tetramethyl succinonitrile5 ppm5 ppm [Unch]
Tetranitromethane5 ppm4 ppm
TetrylN.E.750 mg/m3
Thallium (soluble compounds, as Tl)20 mg Tl/m315 mg Tl/m3
Thiram1,500 mg/m3100 mg/m3
Tin (inorganic compounds, as Sn)400 mg Sn/m3100 mg Sn/m3
Tin (organic compounds, as Sn)Unknown25 mg Sn/m3
Titanium dioxideN.E.5,000 mg/m3
Toluene2,000 ppm500 ppm
Toluene 2,4-diisocyanate10 ppm2.5 ppm
o-Toluidine100 ppm50 ppm
Tributyl phosphate125 ppm30 ppm
1,1,2-Trichloroethane500 ppm100 ppm
Trichloroethylene1,000 ppm1,000 ppm [Unch]
TrichloronaphthaleneUnknownUnknown [Unch]
1,2,3-Trichloropropane1,000 ppm100 ppm
1,1,2-Trichloro 1,2,2-trifluoroethane4,500 ppm2,000 ppm
Triethylamine1,000 ppm200 ppm
Trifluorobromomethane50,000 ppm40,000 ppm
2,4,6-Trinitrotoluene1,000 mg/m3500 mg/m3
Triorthocresyl phosphate40 mg/m340 mg/m3 [Unch]
Triphenyl phosphateN.E.1,000 mg/m3
Turpentine1,500 ppm800 ppm
Uranium (insoluble compounds, as U)30 mg U/m310 mg U/m3
Uranium (soluble compounds, as U)20 mg U/m310 mg U/m3
Vanadium dust70 mg/m3 (as V2O5)35 mg V/m3
Vanadium fume70 mg/m3 (as V2O5)35 mg V/m3
Vinyl toluene5,000 ppm400 ppm
Warfarin350 mg/m3100 mg/m3
Xylene (o, m, p isomers)1,000 ppm900 ppm
Xylidine150 ppm50 ppm
Yttrium compounds (as Y)N.E.500 mg Y/m3
Zinc chloride fume4,800 mg/m350 mg/m3
Zinc oxide2,500 mg/m3500 mg/m3
Zirconium compounds (as Zr)500 mg Zr/m325 mg Zr/m3
Contact Us:
  • Page last reviewed: December 4, 2014
  • Page last updated: December 4, 2014 The U.S. Government's Official Web PortalDepartment of Health and Human Services
Centers for Disease Control and Prevention   1600 Clifton Rd. Atlanta, GA 30329-4027, USA
800-CDC-INFO (800-232-4636) TTY: (888) 232-6348 - Contact CDC-INFO