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