IDLH values (Immediately Dangerous to Life or Health)
An IDLH value is the airborne concentration NIOSH considers immediately dangerous to life or health: exposure could cause death, irreversible health effects, or impair the ability to escape. IDLH values drive respirator selection — above the IDLH only a full-facepiece pressure-demand SCBA or equivalent is acceptable.
113 chemicals in our database. Values are for the pure substance from public sources; check your supplier's SDS for your product.
See also: What is IDLH?
| Chemical | CAS | IDLH | Signal word |
|---|---|---|---|
| (+-)-2-Butanol | 78-92-2 | 2000 ppm (NIOSH, 2024) | Warning |
| 1-Butanol | 71-36-3 | 1400 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| 1-Propanol | 71-23-8 | 800 ppm (NIOSH, 2024) | Danger |
| 1,1,1-Trichloroethane | 71-55-6 | 700 ppm (NIOSH, 2024) | Warning |
| 1,2,4-Trimethylbenzene | 95-63-6 | N.D. See: IDLH INDEX | Warning |
| 1,3-Butadiene | 106-99-0 | 2000 ppm ; Based on 10% of the lower explosive limit; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| 2-Butoxyethanol | 111-76-2 | 700 ppm (NIOSH, 2024) | Danger |
| 2-Heptanone | 110-43-0 | 800 ppm (NIOSH, 2024) | Warning |
| 2-Pentanol | 6032-29-7 | 500 ppm See: IDLH INDEX | Warning |
| 2-Pentanone | 107-87-9 | 1500 ppm (NIOSH, 2024) | Danger |
| 5-Methyl-2-hexanone | 110-12-3 | N.D. See: IDLH INDEX | Warning |
| Acetic Acid | 64-19-7 | 50 ppm (NIOSH, 2024) | Danger |
| Acetone | 67-64-1 | 2500 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Acetonitrile | 75-05-8 | 137 ppm (NIOSH, 2024) | Danger |
| Acetylene | 74-86-2 | N.D. See: IDLH INDEX | Danger |
| Acrylamide | 79-06-1 | 60 mg/m3 ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Acrylic Acid | 79-10-7 | N.D. See: IDLH INDEX | Danger |
| Allyl Alcohol | 107-18-6 | 20 ppm (NIOSH, 2024) | Danger |
| Alpha-Methylstyrene | 98-83-9 | 700 ppm (NIOSH, 2024) | Warning |
| Ammonia | 7664-41-7 | 300 ppm [From NPG: Ammonia] (NIOSH, 2024) | Danger |
| Ammonium Hydroxide | 1336-21-6 | 300 ppm /Ammonia/ | Danger |
| Aniline | 62-53-3 | 100 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Anthracene | 120-12-7 | NIOSH considers coal tar pitch volatiles to be potential occupational carcinogens. /Coal tar pitch volatiles/ | Danger |
| Arsenic | 7440-38-2 | 5 mg As/m3 ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Benzene | 71-43-2 | 500 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Biphenyl | 92-52-4 | 100 mg/m3 (NIOSH, 2024) | Warning |
| Borax (B4Na2O7.10H2O) | 1303-96-4 | N.D. See: IDLH INDEX | Danger |
| Butane | 106-97-8 | 1600 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Butyl Acetate | 123-86-4 | 1700 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Warning |
| Cadmium | 7440-43-9 | 9 mg Cd/m3 ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Calcium Hydroxide | 1305-62-0 | N.D. See: IDLH INDEX | Danger |
| Calcium Oxide | 1305-78-8 | 25 mg/m3 (NIOSH, 2024) | Danger |
| Camphor | 76-22-2 | 200 mg/m3 (NIOSH, 2024) | Danger |
| Carbon Dioxide | 124-38-9 | 40000 ppm (NIOSH, 2024) | Warning |
| Carbon Monoxide | 630-08-0 | 1200 ppm (NIOSH, 2024) | Danger |
| Chlorine | 7782-50-5 | 10 ppm (NIOSH, 2024) | Danger |
| Chloroform | 67-66-3 | 500 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Chromium Trioxide | 1333-82-0 | 15 mg Cr(VI)/m3 ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Chrysene | 218-01-9 | NIOSH considers coal tar pitch volatiles to be potential occupational carcinogens. /Coal tar pitch volatiles/ | Danger |
| Copper Sulfate | 7758-98-7 | 100.0 [mg/m3], as Cu | Warning |
| Cumene | 98-82-8 | 900 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Cyclohexane | 110-82-7 | 1300 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Cyclohexanol | 108-93-0 | 400 ppm (NIOSH, 2024) | Warning |
| Cyclohexanone | 108-94-1 | 700 ppm (NIOSH, 2024) | Warning |
| Diacetone Alcohol | 123-42-2 | 1800 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Warning |
| Dichloromethane | 75-09-2 | 2300 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Warning |
| Diethyl Ether | 60-29-7 | 1900 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Dimethylformamide | 68-12-2 | 500 ppm (NIOSH, 2024) | Danger |
| Diphenylmethane diisocyanate | 101-68-8 | 75 mg/m3 (NIOSH, 2024) | Danger |
| Epichlorohydrin | 106-89-8 | 75 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Ethanol | 64-17-5 | 3300 ppm ; Based on 10% of the lower explosive limit. [From NPG: Ethyl alcohol] (NIOSH, 2024) | Danger |
| Ethanolamine | 141-43-5 | 30 ppm (NIOSH, 2024) | Danger |
| Ethyl Acetate | 141-78-6 | 2000 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Ethyl ketone | 96-22-0 | N.D. See: IDLH INDEX | Danger |
| Ethylbenzene | 100-41-4 | 800 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Ethylene Glycol | 107-21-1 | N.D. See: IDLH INDEX | Warning |
| Ethylene Oxide | 75-21-8 | 800 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Fluoranthene | 206-44-0 | NIOSH considers coal tar pitch volatiles to be potential occupational carcinogens. /Coal tar pitch volatiles/ | Warning |
| Fluorene | 86-73-7 | NIOSH considers coal tar pitch volatiles to be potential occupational carcinogens. /Coal tar pitch volatiles/ | Warning |
| Formaldehyde | 50-00-0 | 20 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Furfuryl Alcohol | 98-00-0 | 75 ppm (NIOSH, 2024) | Danger |
| Glycerol | 56-81-5 | N.D. See: IDLH INDEX | — |
| Heptane | 142-82-5 | 750 ppm (NIOSH, 2024) | Danger |
| Hexane | 110-54-3 | 1100 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Hydrochloric Acid | 7647-01-0 | 50 ppm [From NPG: Hydrogen chloride] (NIOSH, 2024) | Danger |
| Hydrofluoric Acid | 7664-39-3 | 30 ppm [From NPG: Hydrogen fluoride] (NIOSH, 2024) | Danger |
| Hydrogen Peroxide | 7722-84-1 | 75 ppm [From NPG: Hydrogen peroxide] (NIOSH, 2024) | Danger |
| Hydrogen Sulfide | 7783-06-4 | 100 ppm (NIOSH, 2024) | Danger |
| Isoamyl Alcohol | 123-51-3 | 500 ppm (NIOSH, 2024) | Danger |
| Isobutanol | 78-83-1 | 1600 ppm (NIOSH, 2024) | Danger |
| Isophorone | 78-59-1 | 200 ppm (NIOSH, 2024) | Warning |
| Isopropanol | 67-63-0 | 2000 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Lead | 7439-92-1 | 100 mg Pb/m3 (NIOSH, 2024) | Danger |
| M-Xylene | 108-38-3 | 900 ppm (NIOSH, 2024) | Warning |
| Mercury | 7439-97-6 | 10 mg Hg/m3 (NIOSH, 2024) | Danger |
| Mesityl oxide | 141-79-7 | 1400 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Warning |
| Mesitylene | 108-67-8 | N.D. See: IDLH INDEX | Warning |
| Methanol | 67-56-1 | 6000 ppm (NIOSH, 2024) | Danger |
| Methyl Ethyl Ketone | 78-93-3 | 3000 ppm (NIOSH, 2024) | Danger |
| Methyl Isobutyl Ketone | 108-10-1 | 500 ppm (NIOSH, 2024) | Danger |
| Methyl Methacrylate | 80-62-6 | 1000 ppm (NIOSH, 2024) | Danger |
| Naphthalene | 91-20-3 | 250 ppm (NIOSH, 2024) | Warning |
| Nitric Acid | 7697-37-2 | 25 ppm (NIOSH, 2024) | Danger |
| Nitrous Oxide | 10024-97-2 | N.D. See: IDLH INDEX | Danger |
| O-Xylene | 95-47-6 | 900 ppm (NIOSH, 2024) | Warning |
| Ozone | 10028-15-6 | 5 ppm (NIOSH, 2024) | Danger |
| P-Xylene | 106-42-3 | 900 ppm (NIOSH, 2024) | Warning |
| Pentaerythritol | 115-77-5 | N.D. See: IDLH INDEX | — |
| Phenanthrene | 85-01-8 | NIOSH considers coal tar pitch volatiles to be potential occupational carcinogens. /Coal tar pitch volatiles/ | Warning |
| Phenol | 108-95-2 | 250 ppm [From NPG: Phenol] (NIOSH, 2024) | Danger |
| Phosphoric Acid | 7664-38-2 | 1000 mg/m3 (NIOSH, 2024) | Danger |
| Potassium Dichromate | 7778-50-9 | 250 mg/cu m (as Cr(II)). /Chromium(II) compounds (as Cr)/ | Danger |
| Potassium Hydroxide | 1310-58-3 | N.D. See: IDLH INDEX | Danger |
| Potassium Permanganate | 7722-64-7 | 500 mg/cu m /Manganese compounds and fume (as Mn)/ | Danger |
| Propane | 74-98-6 | 2100 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Propargyl alcohol | 107-19-7 | N.D. See: IDLH INDEX | Danger |
| Propylene Oxide | 75-56-9 | 400 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Pyrene | 129-00-0 | NIOSH considers coal tar pitch volatiles to be potential occupational carcinogens. /Coal tar pitch volatiles/ | Warning |
| Silver Nitrate | 7761-88-8 | 10 mg Ag/m3 (NIOSH, 2024) | Danger |
| Sodium Cyanide | 143-33-9 | 25 mg CN/m3 (NIOSH, 2024) | Danger |
| Sodium Hydroxide | 1310-73-2 | 10 mg/m3 [From NPG: Sodium hydroxide] (NIOSH, 2024) | Danger |
| Sodium Pyrosulfite | 7681-57-4 | N.D. See: IDLH INDEX | Danger |
| Styrene | 100-42-5 | 700 ppm (NIOSH, 2024) | Danger |
| Sulfuric Acid | 7664-93-9 | 15 mg/m3 (NIOSH, 2024) | Danger |
| tert-Butanol | 75-65-0 | 1600 ppm (NIOSH, 2024) | Danger |
| Tetrachloroethylene | 127-18-4 | 150 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Warning |
| Tetrahydrofuran | 109-99-9 | 2000 ppm ; Based on 10% of the lower explosive limit. (NIOSH, 2024) | Danger |
| Titanium dioxide | 13463-67-7 | 5000 mg/m3 ; A potential occupational carcinogen. (NIOSH, 2024) | Warning |
| Toluene | 108-88-3 | 500 ppm (NIOSH, 2024) | Danger |
| Toluene 2,4-Diisocyanate | 584-84-9 | 2.5 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Trichloroethylene | 79-01-6 | 1000 ppm ; A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Vinyl Chloride | 75-01-4 | A potential occupational carcinogen. (NIOSH, 2024) | Danger |
| Zinc Oxide | 1314-13-2 | 500 mg/m3 (NIOSH, 2024) | Warning |