Lab Safety
Flammable and Combustible Chemicals
Flammable and combustible chemicals are the most commonly used hazardous chemicals. The hazard of a flammable or combustible chemical is based on its flash point, and, in the case of a flammable chemical, its boiling point as well. The National Fire Protection Association (NFPA) has identified flammability classes from the flash point and boiling point data of chemicals. The following table lists some common flammable and combustible chemicals, their flash points and boiling points, and associated NFPA flammability classes:
Flammable Liquid
Class IA liquids shall include those liquids that have a flash point below 73°F (22.8°C) and a boiling point below 100°F(37.8°C).
Class IB liquids shall include those liquids that have a flash point below 73°F (22.8°C) and a boiling point at or above 100°F(37.8°C).
Class IC liquids shall include those liquids that have flash points at or above 73°F (22.8°C) but below 100°F (37.8°C).
Combustible Liquid
Class II shall include those liquids that have a flash point at or above 100°F (37.8°C) and below 140°F (60°C).
Class IIIA shall include those liquids that have a flash point at or above 140° (60°C) and below 200°F (93°C).
Class IIIB shall include those liquids with a flash point at or above 200°F (93°C).
| Chemical | Flash Point | Boiling Point | NFPA Class | ||
| ° F | ° C | ° F | ° C | ||
| Acetaldehyde | -38 | -39 | 69 | 21 | IA |
| Dimethyl sulfide | -36 | -38 | 99 | 37 | IA |
| Ethyl ether | -49 | -45 | 95 | 35 | IA |
| Ethylene oxide | -20 | -29 | 55 | 13 | IA |
| Pentane | -57 | -49 | 97 | 36 | IA |
| Propane | -157 | -105 | -44 | -42 | IA |
| Benzene | 12 | -11 | 176 | 80 | IB |
| Carbon disulfide | -22 | -30 | 115 | 46 | IB |
| Cyclohexane | -4 | -20 | 179 | 81 | IB |
| Ethyl alcohol | 55 | 13 | 173 | 78 | IB |
| n-Hexane | -7 | -22 | 156 | 69 | IB |
| Methyl alcohol | 52 | 11 | 149 | 65 | IB |
| Methyl ethyl ketone | 16 | -9 | 176 | 80 | IB |
| Pyridine | 68 | 20 | 239-241 | 116 | IB |
| Tetrahydrofuran | 6 | -14 | 153 | 67 | IB |
| Toluene | 40 | 4 | 231 | 111 | IB |
| Triethylamine | 20 | -7 | 193 | 89 | IB |
| tert Butyl isocyanate | 80 | 27 | 185-187 | 85-86 | IC |
| Chlorobenzene | 82 | 28 | 270 | 132 | IC |
| Epichlorohydrin | 88 | 31 | 239-243 | 115-117 | IC |
| 2-Nitropropane | 75 | 24 | 248 | 120 | IC |
| Xylene | 81-90 | 27-32 | 280-291 | 138-144 | IC |
| Acetic Acid, glacial | 103 | 39 | 244 | 48 | II |
| Bromobenzene | 118 | 48 | 307-316 | 153-158 | II |
| Formic Acid | 156 | 69 | 213 | 101 | II |
| Morpholine | 100 | 38 | 263 | 128 | II |
| Stoddard Solvent | 100-140 | 38-60 | 300-400 | 150-200 | II |
| Benzaldehyde | 145 | 63 | 352 | 178 | IIIA |
| Cyclohexanol | 154 | 68 | 322 | 161 | IIIA |
| Methacrylic Acid | 170 | 77 | 316 | 158 | IIIA |
| Nitrobenzene | 190 | 88 | 412 | 211 | IIIA |
| Tetrahydronaphthalene | 160 | 71 | 406 | 208 | IIIA |
| Benzyl Alcohol | 213 | 101 | 401 | 205 | IIIB |
| Caproic Acid | 215 | 102 | 400 | 204 | IIIB |
| Ethylene Glycol | 232 | 111 | 388 | 198 | IIIB |
| Phenyl Ether | 239 | 115 | 498 | 258 | IIIB |
| Stearic Acid | 385 | 196 | 726 | 386 | IIIB |
Degree of Fire Hazards
| Class A | Class B | Class C | Class D |
| High | Moderate | Low | Minimal |
Page last modified May 10, 2010
