Combustible liquid means any liquid having a flash point at or above 100 oF (37.8 oC). Combustible liquids shall be divided into two classes as follows: Class II Liquids -
Liquids with flash points at or above 100 oF (37.8 oC) and below 140 oF (60 oC), except any mixture having components with flash points of 200 oF (93.3 oC) or higher, the volume of which make up 99 percent or more of the total volume of the mixture.

Class III Liquids -
Have flash points at or above 140 oF (60 oC).
Class III liquids are subdivided into two subclasses:

Class IIIA: have flash points at or above 140 oF (60 oC) and below 200 oF (93.3 oC), except any mixture having components with flash points of 200 oF (93.3 oC), or higher, the total volume of which make up 99 percent or more of the total volume of the mixture.

Class IIIB: liquids shall include those with flash points at or above 200 oF (93.3 oC). This section does not regulate Class IIIB liquids. Where the term "Class III liquids" is used in this section, it shall mean only Class IIIA liquids.

**When a combustible liquid is heated to within 30 oF (16.7 oC) of its flash point, it shall be handled in accordance with the requirements for the next lower class of liquids.


Flammable liquid means any liquid having a flash point below 100 oF (37.8 oC) or higher, the total of which make up 99 percent or more of the total volume of the mixture.
Flammable liquids shall be known as Class I liquids.
Class I liquids are divided into three classes as follows:

Class IA shall include liquids having flash points below 73 oF (22.8 oC) and having a boiling point below 100 oF (37.8 oC).

Class IB shall include liquids having flash points below 73 oF (22.8 oC) and having a boiling point at or above 100 oF (37.8 oC).

Class IC shall include liquids having flash points at or above 73 oF (22.8 oC) and below 100 oF (37.8 oC).


Below is a chart of some common Flammable and Combustible Liquids:

Class IA

Liquid		Flash Point (°F)	Boiling Point (°F)	Flammable Limits		Vapor Density Air = 1	PEL (ppm)
Common Name	Other Names			LEL	UEL
1-1 Dichloroethylene	Vinylidene chloride	0	99	7.3	10.0	3.4	-
Ethylamine		<0	63	3.5	14.0	1.6	10
Ethyl Chloride	Chloroethane	-58	54	3.8	15.4	2.2	1000
Ethyl Ether	Ether	-49	95	1.9	36.0	2.6	400
Isopentane		<-60	82	1.4	7.6	2.5	-
Isopropyl Chloride	2-Chloropropane	-26	97	2.8	10.7	2.7	-
Methyl Formate		-2	90	5.0	23.0	2.1	100
Pentane		<-40	97	1.5	7.8	2.5	1000
Propylene Oxide		-35	93	2.8	37.0	2.0	100

 

Class IB

Liquid		Flash Point (°F)	Boiling Point (°F)	Flammable Limits		Vapor Density Air = 1	PEL (ppm)
Common Name	Other Names			LEL	UEL
Acetone		0	134	2.6	12.8	2.0	1000
Benzene	Benzol	12	176	1.3	7.1	2.8	1
Carbon Disulfide	Carbon bisulfide	-22	115	1.3	50.0	2.6	20
1,2-Dichloroethylene	Acetylene dichloride	43	140	9.7	12.8	3.4	200
Ethyl Acetate		24	171	2.2	11.0	3.0	400
Ethyl Alcohol	Ethanol, Grain alcohol	55	173	3.3	19	1.6	1000
Ethyl Benzene		59	277	1.0	6.7	3.7	100
Gasoline		-45	100-399	1.4	7.6	3-4	-
Hexane		-7	156	1.1	7.5	3.0	500
Methyl Acetate		14	135	3.1	16	2.6	200
Methyl Alcohol	Wood alcohol, Methanol	52	147	6.7	3.6	1.1	200
Methyl Ethyl Ketone	MEK, 2-Butanone	21	176	1.8	10	2.5	200
Methyl Propyl Ketone	2-Pentanone	45	216	1.5	8.2	2.9	200
VM&P Naphtha	76 Naphtha	20-45	212-320	0.9	6.0	4.2	-
Octane		56	257	1.0	6.5	3.9	500
Propyl Acetate		58	215	2.0	8.0	3.5	200
Isopropyl Acetate		40	192	1.8	8.0	3.5	250
Isopropyl Alcohol	IPA, 2-propanol	53	180	2.0	12	2.1	400
Toluene	Toluol	40	232	1.2	7.1	3.1	200
Butyl Acetate		72	260	1.7	7.6	4.0	150

 

Class IC

Liquid		Flash Point (°F)	Boiling Point (°F)	Flammable Limits		Vapor Density Air = 1	PEL (ppm)
Common Name	Other Names			LEL	UEL
Isoamyl Acetate	Banana Oil	77	288	1.0	7.5	4.5	100
Amyl Alcohol	Pentanol	91	281	1.2	10	3.0
Butyl	Butanol	84	243	1.4	11.2	2.6	100
Methyl Isobutyl Ketone	MIBK, Hexone	73	246	1.4	7.5	3.5	100
Naphtha (Petroleum)	Mineral Spirits, Petroleum Ether	85-110	302-399	0.8	6.0	4.2	-
Propyl Alcohol	Propanol	77	208	2.1	13.5	2.1	200
Styrene (Monomer)	Vinyl Benzene	90	295	1.1	6.1	3.6	100
Turpentine		95	307-347	0.8	-	-	100
Xylene	Xylol	81-115	281-291	1.1	7.0	3.7	100

 

Class II

Liquid		Flash Point (°F)	Boiling Point (°F)	Flammable Limits		Vapor Density Air = 1	PEL (ppm)
Common Name	Other Names			LEL	UEL
Isoamyl		109	268	1.2	-	3.0	100
Cellosolve Acetate	2-Ethoxyethyl acetate	117	313	1.7	-	4.7	100
Cyclohexanone		111	313	-	-	3.4	50
Fuel Oil #1 & #2		100+	-	-	-	-	-
Fuel Oil #4		110+	-	-	-	-	-
Fuel Oil #5		130+	-	-	-	-	-
Kerosene		110-150	180-300	0.7	5.0	4.5	-
Naphtha (coal tar)		100-110	300-400	-	-	4.3	100
Naphtha (High Flash)	100 Naptha Safety Solvent, Stoddard Solvent	100-110	300-400	0.8	6.0	>4.2	500
Methyl Cellosolve	2-Methoxyethanol	115	255	2.5	14.0	-	25

 

Class III

Liquid		Flash Point (°F)	Boiling Point (°F)	Flammable Limits		Vapor Density Air = 1	PEL (ppm)
Common Name	Other Names			LEL	UEL
Aniline		158	363	1.3	-	3.2	5
Butyl Cellosolve	2-Butoxyethanol	160	340	1.1	10.6	4.1	50
Cellosolve Solvent	2-Ethozyethanol Cellosolve Solvent	202	275	1.8	14.0	3.1	200
Cyclohexanol		162	322	-	-	2.5	50
Ethylene Glycol	Glycol	232	387	3.2	-	-	-
Furfural		140	324	2.1	19.3	3.3	5
Glycerine	Glycerol	320	554	-	-	3.2	-
Isophorone		184	419	0.8	3.8	-	25
Nitrobenzene		190	412	-	-	4.3	1

 

Non-Flammable Liquids (*)

Liquid		Boiling Point (°F)	PEL (ppm)
Common Name	Other Names
Carbon Tetrachloride		171	10
Chloroform	Trichloromethane	142	50
Ethylene Dibromide	1,2-Dibromoethane	270	20
Methyl Chloroform	1,1,1-Trichloroethane	165	350
Methylene Chloride	Dichloromethane	104	500
Perchloroethylene	Tetrachloroethylene	248	100
Trichloroethylene	TCE, Trichlor	190	100

(*) Non-flammable under normal conditions. Unstabilized trichloroethylene can decompose violently in presence of fine aluminum powder.