Chapter 11
Volatile Organic Compounds
11.1 INTRODUCTION
Volatile organic compounds (VOCs) are those organic compounds which have
a boiling-point within the range 50–100 to 240–260
C.
1 They include a large
number of major air pollutants, emitted from both industrial and nonindustrial facilities. Chemically, VOCs include aliphatic and aromatic hydrocarbons, halogenated hydrocarbons, some alcohols, esters, and aldehyes. Table
11.1 shows several examples of this group of compounds. The importance of
VOCs as a class of air pollutants is evident in view of the fact that the U.S.
Environmental Protection Agency (EPA) has designated them as one of the six
‘‘Criteria Air Pollutants.’’ In this chapter, the sources, characteristics, and
health effects of some examples of VOCs are discussed.
11.2 SOURCES
Both natural and anthropogenic sources contribute to VOC emissions. Natural
sources of VOCs include petroleum, forest fires, and the transformation of
biogenic precursors. Main anthropogenic sources include high-temperature
combustion of fuels, emissions from crude and refined oil, municipal
incineration, burning of crops before or after harvesting as an agricultural
practice, emissions from powerboats, and others. In terms of the quantities of
anthropogenic material emitted from the U.S. during 1998, five major air
pollutants, i.e., carbon monoxide (CO), sulfur oxides (SO x ), nitrogen oxides
(NO x ), VOCs, and particulate matter (PM), accounted for 98% of total
pollution, and VOC emissions alone contributed 14%. Following the passage
[16:52 26/8/04 P:/CRC PRESS/4365 MING-HO.751 (1670)/4365-011.3d]
Ref: 4365 MING-HO YU Chap-011 Page: 171 171-184
171
Table 11.1 Examples of Volatile Organic Compounds
Group
Examples
Aliphatics
Pentane, hexane, heptane, cyclohexane, octane, nonane, eicosane,
dodecane, 2,4-dimethylhexane
Aromatic
hydrocarbons
Benzene, diethylbenzene, trimethylbenzenes, dimethyl-ethylbenzene,
toluene, xylenes, naphthalene, styrene
Halogenated
hydrocarbons
Chloroform, dichlormethane, trichloroethylene, tetrachloroethylene,
dichlorobenzenes
Alcohols
2-Butylalcohol, 1-dodecanol
Aldehydes
Decanal, nonanal
Esters
Ethyl acetate, 1-hexyl butanoate
Volatile Organic Compounds
11.1 INTRODUCTION
Volatile organic compounds (VOCs) are those organic compounds which have
a boiling-point within the range 50–100 to 240–260
C.
1 They include a large
number of major air pollutants, emitted from both industrial and nonindustrial facilities. Chemically, VOCs include aliphatic and aromatic hydrocarbons, halogenated hydrocarbons, some alcohols, esters, and aldehyes. Table
11.1 shows several examples of this group of compounds. The importance of
VOCs as a class of air pollutants is evident in view of the fact that the U.S.
Environmental Protection Agency (EPA) has designated them as one of the six
‘‘Criteria Air Pollutants.’’ In this chapter, the sources, characteristics, and
health effects of some examples of VOCs are discussed.
11.2 SOURCES
Both natural and anthropogenic sources contribute to VOC emissions. Natural
sources of VOCs include petroleum, forest fires, and the transformation of
biogenic precursors. Main anthropogenic sources include high-temperature
combustion of fuels, emissions from crude and refined oil, municipal
incineration, burning of crops before or after harvesting as an agricultural
practice, emissions from powerboats, and others. In terms of the quantities of
anthropogenic material emitted from the U.S. during 1998, five major air
pollutants, i.e., carbon monoxide (CO), sulfur oxides (SO x ), nitrogen oxides
(NO x ), VOCs, and particulate matter (PM), accounted for 98% of total
pollution, and VOC emissions alone contributed 14%. Following the passage
[16:52 26/8/04 P:/CRC PRESS/4365 MING-HO.751 (1670)/4365-011.3d]
Ref: 4365 MING-HO YU Chap-011 Page: 171 171-184
171
Table 11.1 Examples of Volatile Organic Compounds
Group
Examples
Aliphatics
Pentane, hexane, heptane, cyclohexane, octane, nonane, eicosane,
dodecane, 2,4-dimethylhexane
Aromatic
hydrocarbons
Benzene, diethylbenzene, trimethylbenzenes, dimethyl-ethylbenzene,
toluene, xylenes, naphthalene, styrene
Halogenated
hydrocarbons
Chloroform, dichlormethane, trichloroethylene, tetrachloroethylene,
dichlorobenzenes
Alcohols
2-Butylalcohol, 1-dodecanol
Aldehydes
Decanal, nonanal
Esters
Ethyl acetate, 1-hexyl butanoate