United States
Environmental Protection
Agency
Office of Air Quality
Planning and Standards
Research Triangle Park NC 27711
EPA-450/1-92-001
January 1992
Air/Superfund
&EPA
AIR/SUPERFUND
NATIONAL TECHNICAL
GUIDANCE STUDY SERIES
ESTIMATION OF AIR IMPACTS FOR
SOIL VAPOR EXTRACTION (SVE)
SYSTEMS
U.S. Environment
Region 5, Libi-ry
77 West Jacksc;, .
Chicago, IL 60ou-
-------
EPA - 450/1-92-001
AIR/SUPERFUND NATIONAL TECHNICAL
GUIDANCE STUDY SERIES
Estimation of Air Impacts
for Soil Vapor Extraction
(SVE) Systems
Prepared by:
Bart Eklund
Sandy Smith
Pat Thompson
Abds-Sami Malik
Radian Corporation
Austin, Texas
EPA Contract Number 68-D1-0031
Prepared for:
James F. Durham
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
January, 1992
-------
DISCLAIMER
This report has been reviewed by the Office of Air Planning and Standards,
U.S. Environmental Protection Agency, and has been approved for
publication. Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
-------
TABLE OF CONTENTS
Page
INTRODUCTION 1
PROCESS DESCRIPTION 2
ESTIMATION OF AIR EMISSIONS 4
ESTIMATION OF AMBIENT AIR CONCENTRATIONS 8
ESTIMATION OF HEALTH EFFECTS 16
EXAMPLE 26
CONCLUSIONS 30
ACKNOWLEDGEMENTS 30
REFERENCES 31
APPENDIX A: PHYSICAL AND CHEMICAL CONSTANTS FOR
SELECTED COMPOUNDS
11
-------
LIST OF FIGURES
1 Generalized Process Flow Diagram for Soil Vapor Extraction 3
2 One-Hour Average Downwind Dispersion Factor Versus Distance
for SVE System With No Air Emission Controls 9
3 One-Hour Average Downwind Dispersion Factor Versus Distance
for SVE System With Activated Carbon Controls 10
4 One-Hour Average Downwind Dispersion Factor Versus Distance
for SVE System With Catalytic Oxidation Controls 13
5 Comparison of One-Hour Average Downwind Dispersion Factor
Versus Distance for SVE Systems With Various Control Options .... 15
LIST OF TABLES
1 Example Scenarios for SVE with No Controls Based on
Size of System 10
2 Example Scenarios for SVE with Activated Carbon Controls
Based on Size of System 14
3 Example Scenarios for SVE with Catalytic Oxidation Controls
Based on Size of System 14
4 Long-Term and Short-Term Health-Based Action Levels for
Ambient Air 17
5 Estimated Emission Rates and Ambient Air Concentrations 28
6 Action Level Concentrations 28
in
-------
INTRODUCTION
The U.S. Environmental Protection Agency's Office of Air Quality
Planning and Standards and the Regional Air Offices have been given the responsibility
to evaluate air impacts from Superfund sites. An important part of this program is the
analysis of air impacts from various alternatives for cleaning up Superfund sites. Since
these analyses are frequently required for planning purposes prior to actual cleanup they
depend on estimated emissions and ambient concentrations rather than on field
measurements.
This report provides procedures for roughly estimating the ambient air
concentrations associated with soil vapor extraction (SVE). The procedures for SVE
systems are analogous to procedures for air strippers that have previously been
published1. SVE is also known as soil venting, vacuum extraction, aeration, or in-situ
volatilization. It is a widely used technique for removing volatile organic compound
(VOC) vapors from contaminated soil. Procedures are given to evaluate the effect of
the concentration of the contaminants in the soil-gas and the extraction rate on the
emission rates and on the ambient air concentrations at selected distances from the SVE
system.
Health-based ambient air action levels are also provided for comparison to
the estimated ambient concentrations. Many of the health levels have not been verified
by EPA or are based on extrapolations of oral exposures or occupational exposures.
Their indiscriminate use could either under or over estimate the potential health effects.
The statements and conclusions presented in this report are those of the authors and do
not reflect U.S. EPA policy.
-------
PROCESS DESCRIPTION
Soil vapor extraction systems involve the removal of air containing volatile
compounds from unsaturated soil. A general process schematic is shown in Figure 1.
One or more extraction wells are placed in the vadose (unsaturated) zone at the site of
the contamination. The extraction wells typically are constructed of slotted plastic pipe
placed in permeable packing such as coarse sand. The wells are connected via a
manifold that leads to an air blower or vacuum pump. The vacuum pump is used to
withdraw air from the extraction wells and is typically capable of inducing a vacuum of
about 30 in. Hg. The subsurface vacuum that is created and the resulting pressure
gradient in the soil will dictate the rate at which vapors are withdrawn and the air flow
patterns in the vadose zone.
As shown in Figure 1, air inlet wells can be used to introduce ambient air
at the edge of the contaminated area. They serve to both increase the rate that
contaminant-laden air is extracted and to control the direction of vapor migration. The
air inlet wells can be passive or air can be forced into the ground using an air blower.
Only a fraction of the extracted air comes from the air inlets, with the remainder of the
air drawn from the surface through the soil. Therefore, it is important to have an
impermeable cap in place at the top of each extraction well to prevent the direct inflow
of ambient air down the well casing.
Several design options are available for increasing the air flowrate and
removal efficiency of an SVE system. The inlet air can be heated to increase the
partitioning of subsurface contaminants into the vapor-phase. The air blower used to
inject air into the ground will heat the air to some extent due to compression; additional
heat is added in some SVE systems by also injecting steam into the ground. In some
cases, the air inlet wells extend down into the saturated zone. The inlet air bubbles up
through the water table and this sparging action can enhance the removal of slightly
soluble volatile organic compounds.
-------
Clean Flue Gas
VAPOR-LIQUID
SEPARATOR
VadoseZone
Water Table
Figure 1. Generalized Process Flow Diagram for Soil Vapor Extraction.
-------
An air/water separator is typically employed if water is pulled from the
extraction wells. The separator serves to protect the air blowers or pumps and to
increase the efficiency of any vapor treatment system that is used. The condensate from
the separator may require treatment prior to discharge. For the large-scale remediations
done at Superfund Sites, the air stream will normally require treatment to reduce its
VOC content prior to discharge into the atmosphere. Carbon adsorption or catalytic
oxidation are the most commonly used control technologies. Carbon adsorption systems
may be present upstream or downstream of the vacuum pump. For SVE systems with
small air flowrates (i.e., 30 to 100 scfm), internal combustion engines can also be used to
control the air emissions.
ESTIMATION OF AIR EMISSIONS
There are several alternative approaches for estimating the emissions from
a SVE system. The best method is to directly measure the emissions from the system
while it is in full-scale or pilot-scale operation. The next best method is to estimate the
emissions using predictive equations with site-specific inputs. If site-specific inputs are
not available, a very conservative estimate can be made by using default values for the
input parameters. Equations are given below for estimating long-term average and
short-term emission rates.
Long-Term Average Emission Rate
A simple check of the total emissions potential for the site should also be
made by dividing the total mass of a given contaminant to be removed from the soil by
the expected duration of the clean-up:
ER = (SV)(CS)(B)(1)/ t (Eq. 1)
where: ER = Average emission rate (g/sec);
Sv = Volume of contaminated soil to be treated (m3);
Cs = Average contaminant concentration (ug/g);
-------
B = Bulk density of soil (g/cm3);
1 = Constant (g/106ug * 106cm7m3); and
t = Duration of remediation (sec).
Equation 1 assumes 100% recovery of the contamination at the site. The volume of
contaminated soil and the total mass of each contaminant of concern are typically
determined during the remedial investigation (RI) of the site, while the percent that can
be recovered using SVE is typically determined during the feasibility study (FS) of the
site. The duration of the clean-up will usually be limited by the rate at which
contaminants can be cost-effectively extracted from the ground (see below). For
Equation 1, a typical default value for bulk density of uncompacted soil is 1.5 g/cm3.
The following paragraphs discuss the key variables influencing air emissions from SVE
systems and present an empirical equation for estimating a short-term emission rate.
Short-Term Emission Rate
The primary parameters affecting the emission rate of a given compound
from a SVE system are: the concentration of the contaminant in the soil, the volatility of
the contaminant (i.e. its vapor pressure), the soil permeability to air flow, and the
vacuum well pressure. The soil permeability will depend on a number of factors
including: air-filled porosity of the soil, the soil moisture content, the bulk soil
temperature, the density and viscosity of the soil gas, and the presence of any
macropores that result in channelized vapor flow. Due to the complex nature of
subsurface vapor transport and the large variations in soil permeability to air flow at
most sites, accurate prediction of SVE effectiveness and the resulting emissions based on
models or equations derived from fundamental physical laws is not feasible. Instead, the
flow rate of vapors through the soil is usually determined empirically and then used to
estimate the emission rate.
The flow rate of vapors through the soil depends on the pressure gradient
(which in turn is dependent on the soil permeability and the applied vacuum). The
pressure gradient decreases with distance from the extraction well and a radius of
-------
influence exists that defines the extent to which vapors can be drawn to the well. The
length of this radius will vary from site to site and will dictate the number of wells
required to remediate a site and their spacing. In practice, field tests are typically
performed to assess the potential effectiveness of SVE for a given site. The field tests
may be pilot-scale demonstrations of SVE or tests of soil-air permeability2"3.
The results of the field tests can be used to estimate the emission rate
(ER) in grams per second from the SVE system using Equation 2.
(Eq- 2)
where: ER = Emission rate (g/sec);
Cg = Concentration in extracted vapors (ag/rn3);
Q = Vapor extraction rate (m3/min);
1/60 = Conversion factor (min/sec); and
10"6 = Conversion factor (g///g).
The extraction rate, Q, can be estimated from the results of pilot-scale tests at the site if
any changes in pump size and number of wells between the pilot- and full-scale systems
are taken into account. If no pilot-scale data are available, results of field test of soil-air
permeability can be used to estimate Q. If these too are not available, a default value
can be used for the extraction rate. Typical flow rates for Q at Superfund sites range
from 14 m3/min (500 cfm) to 425 m3/min (15,000 cfm), with a typical default value being
Q = 85 m3/min (3,000 cfm).
The contaminant concentration in the extracted vapors, Cg, can also be
estimated from the results of pilot-scale tests at the site. The second best approach is to
estimate Cg by collecting samples of the headspace vapors above the contaminated soil
and measuring the concentration of the compound(s) of interest. These equilibrium soil-
gas samples can be collected using ground (soil-gas) probes or by transferring soil
samples from split-spoon samplers (to minimize VOC losses) to sealed containers and
allowing the headspace to equilibrate.
-------
Field data are required to get an accurate value for Cg. If no field data are
available, however, a very conservative value for Cg can be estimated by assuming that
the soil-gas is saturated. The maximum vapor concentration of any compound in the
extracted vapors is its equilibrium or "saturated" vapor concentration, which is calculated
from the compound's molecular weight, vapor pressure at the soil temperature, and the
ideal gas law3:
- 3)
= (Pvap)(MW * 109)
~
8
where: Cg = Estimate of contaminant vapor concentration (wg/m3);
Pvap = Pure component vapor pressure at the soil temperature (mm Hg);
MW = Molecular weight of component i (g/mole);
R = Gas constant = 62.4 L-mm Hg/mole -°K;
T = Absolute temperature of soil (°K); and
109 = Conversion factor (//g-L/g-m3).
Values of molecular weight, vapor pressure at 25°C, and saturated vapor concentration at
25°C are given in Appendix A. It is important to note that Equation 3 gives the
theoretical maximum value of Cg. It will overpredict Cg for any compounds present in
the soil at relatively low concentrations. Equation 3 will also overpredict the long-term
average value of Cg since the concentration of contaminants in the gas extracted using a
SVE system will tend to drop over time. It can drop by more than 95% in the first two
days of operation2, though pulsed operation will allow the soil-gas concentration to be
periodically re-established at levels near the initial concentration.
Equation 3 assumes that an infinite source of vapors exists and that the
contaminants are present in the soil or ground water at relatively high concentrations
(e.g., total hydrocarbons of 500 ppm in the soil). Therefore, the vapor-phase
concentration for a given compound is independent of the concentration of that same
compound in the soil/liquid matrix.
-------
Site-specific soil temperatures should be used if available. If not, annual
average air temperatures can be used to estimate long-term values. Summer maximum
air temperatures can be used to estimate short-term maximum values, if these are
needed. A conservative default soil temperature is 298°K (25°C). Again, values for
other inputs to Equation 3 can be found in Appendix A.
Emission control technologies used as part of the SVE system can
generally be assumed to reduce emissions by 90 to 95%. The effect on emissions for any
control device could be taken into account by adding the following term to Equation 2:
(1-RE (%)/100)
where: RE = Removal efficiency of control device (%).
Published maximum short-term emission rates for soil vapor extraction
systems are approximately 7 g/sec of total VOCs for systems without emission controls
and approximately 0.35 g/sec for systems with emission controls4.
ESTIMATION OF AMBIENT AIR CONCENTRATIONS
Estimates of short term ambient concentrations should be obtained by
using site specific release parameters in the EPA's SCREEN model5. Estimates of long
term concentrations should be obtained by using EPA's Industrial Source Complex
(ISCLT) model. Here, for simplicity, the long term estimates are derived by multiplying
the short term estimate obtained from the SCREEN model, by a conversion factor to
obtain the annual average estimates. This approach results in a higher estimate of the
annual average concentration than if the ISCLT model, with site specific data, is used.
Three air emission control options are typically employed for SVE systems:
1) no controls; 2) activated carbon control systems; and 3) catalytic oxidation control
systems. Figure 2 was constructed using release parameters for the four different sizes of
SVE systems with no air emission controls described in Table 1. The four scenarios
-------
No Controls
GO
10,000
0)
Q.
3,000
1,000
D) 300
13
O
03
LL
C
CL
GO
Q
100
30
10
3
1
5,000 10,000
10 20 50 100 200 500 1,000 2,000
Downwind Distance (meters)
very small small medium large
Figure 2. One-Hour Average Downwind Dispersion Factor Versus Distance for SVE System With No Air Emission
Controls.
-------
Table 1.
Example Scenarios for SVE with No Controls Based on Size of System
Parameter
Exhaust Gas Flowrate
Exhaust Gas Velocity
Exit Gas Temperature
Stack Height
Stack Diameter
Units
m3/min
cfm
m/sec
°C
m
m
Scenario
Very Small
1.4
50
3.0
50
3.0
0.10
Small
14
500
7.4
50
4.6
0.20
Medium
85
3,000
12.5
50
7.6
0.38
Large
425
15,000
14.2a
50
9.1
0.46
'Assume three adjacent stacks each handling 5,000 cfm. The flow is split to lower the
velocity of the exiting gas to typical design levels to minimize corrosion of the stack.
10
-------
listed in Table 1 vary in exhaust gas flowrate and in stack height and stack diameter (and
in the resulting exhaust gas velocity). The scenarios were developed based on a review
of the existing literature and discussions with researchers in the SVE area6'7'8'9. A flat
terrain without any structures near the SVE system was assumed, and downwash was
taken into account with the emitting stack being the only structure.
Figures 3 and 4 were constructed in an analogous manner to Figure 2 using
the release parameters for SVE systems with activated carbon controls described in
Table 2 and the release parameters for SVE systems with catalytic oxidation controls
described in Table 3, respectively. As before, a flat terrain without any structures near
the SVE system was assumed and downwash was taken into account with the emitting
stack being the only structure.
All three control options assume the same system sizes, operating
conditions, and stack height. The key variable is the exit gas temperature, which is
dependent on the type of emission control device that is used. The exhaust gas flowrates
for a given size of SVE system are the same for each of the control options once
converted to standard cubic meters per minute (scmm). Figure 5 illustrates the effect of
control type (i.e., exhaust gas temperature) on the dispersion factor by comparing a
medium size SVE system with no controls, with activated carbon controls, and with
catalytic oxidation controls.
The figures (2, 3, or 4) can be used to estimate the maximum hourly
ambient air concentration for an emission rate of 1 gram per second at selected distances
downwind from a SVE system with a given type of air emission control system. If the
size of the system is not known, a medium size should be assumed. If the type of
controls are not known, no controls should be assumed. The dispersion factor, in
micrograms/m3 per g/sec, obtained from the figures (2, 3, or 4) can be substituted into
Equation 4 to estimate the maximum hourly ambient concentration and into Equation 5
11
-------
CO
10,000 -T
CD
Q_
CO
O)
D
O
03
c
O
CD
5,000
2,000
1,000
500
200
100
CO
Q
10
Activated Carbon
5,000 10,000
10 20 50 100 200 500 1,000 2,000
Downwind Distance (meters)
very small small medium large
Figure 3. One-Hour Average Downwind Dispersion Factor Versus Distance for SVE System With Activated Carbon
Controls.
-------
co
10,000
Catalytic Oxidation
10 20 50 100 200 500 1,000 2,000 5,000 10,000
Downwind Distance (meters)
very small small medium large
Figure 4. One-Hour Average Downwind Dispersion Factor Versus Distance for SVE System With Catalytic Oxidation
Controls.
-------
Table 2.
Example Scenarios for SVE with Activated Carbon Controls
Based on Size of System
Parameter
Exhaust Gas Flowrate
Exhaust Gas Velocity
Exit Gas Temperature
Stack Height
Stack Diameter
Units
m3/min
cfm
m/sec
°C
m
m
Scenario
Very Small
1.3
46
2.8
25
3.0
0.10
Small
13
461
6.9
25
4.6
0.20
Medium
78
2,770
11.5
25
7.6
0.38
Large
392
13,800
13.1a
25
9.1
0.46
"Assume three adjacent stacks each handling 4,600 cfm. The flow is split to lower the
velocity of the exiting gas to typical design levels to minimize corrosion of the stack.
Table 3.
Example Scenarios for SVE with Catalytic Oxidation Controls
Based on Size of System
Parameter
Exhaust Gas Flowrate
Exhaust Gas Velocity
Exit Gas Temperature
Stack Height
Stack Diameter
Units
m3/min
cfm
m/sec
°C
m
m
Scenario
Very Small
2.6
92
5.5
320
3.0
0.10
Small
26
918
13.8
320
4.6
0.20
Medium
156
5,510
22.9
320
7.6
0.38
Large
780
27,500
26. la
320
9.1
0.46
aAssume three adjacent stacks each handling 9,200 cfm. The flow is split to lower the
velocity of the exiting gas to typical design levels to minimize corrosion of the stack.
14
-------
500
Q.400
CO
E
300
Comparison of Different Control Options
o
-t— '
CO
LL
C
200
100
CD
Q.
o
10 20
I It
• 4
...
****•»
H f \—I—h-4-
1 - 1 - — i i i i
H h
50 100 200 500 1,000 2,000
Downwind Distance (meters)
no controls activated carbon catalytic oxidation
-I—I—I-
5,000 10,000
Figure 5. Comparison of One-Hour Average Downwind Dispersion Factor Versus Distance for SVE Systems With
Various Control Options.
-------
to estimate the annual average ambient air concentration for a given downwind distance.
Since SCREEN provides maximum short-term estimates, the factor of 0.025 in
Equation 4 is used to convert the short-term estimate to a maximum annual average
estimate. A conservative factor of 0.025 assumes that the wind blows downwind 2.5% of
the time over one year and that the terrain is relatively flat. This assumption is under
review by EPA and is subject to change.
Cm = (ER)(F) (Eq. 4)
Ca = (ER)(F)(O.Q25) (Eq. 5)
where: Cm = Maximum hourly ambient air concentration (wg/m3);
Ca = Annual average ambient air concentration (//g/m3);
ER = Emission rate (g/sec); and
F = Dispersion Factor from Figure 2, 3, or 4 (ag/m3/g/sec).
ESTIMATION OF HEALTH EFFECTS
Cancer Effects Due to Long-Term Exposure
Potential cancer effects resulting from long-term exposure to substances
emitted to the air can be evaluated using inhalation unit risk factors. Inhalation unit risk
factors are a measure of the cancer risk for each ^g/m3 of concentration in the ambient
air. They are available on EPA's Integrated Risk Information System (IRIS), the
Agency's preferred source of toxicity information. User Support can be contacted at
(513) 569-7254. Table 4 provides inhalation unit risk factors listed in IRIS as of
January 1991 for selected organic compounds.
The next best source of inhalation unit risk factors is EPA's Health Effects
Assessment Summary Tables (HEAST) which are updated quarterly.10
Equation 6 can be used to estimate the cancer risk at a specified distance
downwind of the air stripper. Cancer risk is a measure of the increased probability of
16
-------
Table 4.
Long-Term and Short-Term Health-Based Action Levels for Ambient Air
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
Chemical
Acetaldehyde
Acetic Acid
Acetic anhydride
Acetone
Acetonitrile
Acrolein
Acrylic acid
Acrylonitrile
Allyl alcohol
Allyl chloride
Aniline
Anthracene
Benzaldehyde
Benzene
Benzoic acid
Benzyl alcohol
Benzyl chloride
Bromoform
1,3-Butadiene
n- Butane
2-Butanol
n-Butanol
n-Butyl-Acetate
Tert-Butyl-Alcohol
Carbon disulfide
CAS Number
75-07-0
64-19-7
108-24-7
67-64-1
75-05-8
107-02-8
79-10-7
107-13-1
107-18-6
107-05-1
62-53-3
120-12-7
100-52-7
71-43-2
65-85-0
100-51-6
100-44-7
75-25-2
106-99-0
106-97-8
15892-23-6
71-36-3
123-86-4
75-65-0
75-15-0
Carcinogenicity*
Inhalation Unit
Risk 1/Oig/m3)
-
-
-
-
-
NDc'e
--
6.8e-05
-
NDc'e
(1.6e-06)b
-
-
8.3e-06
-
-
-
l.le-06c
2.8e-04
-
-
-
-
-
-
Chronic
Toxicity*
Inhalation
RfC (mg/m3)
-
-
-
(4e-01)b
5e-02
le-04c
3e-04
-
(2e-02)b
le-03
-
(le-t-00)b
(4e-01)b
-
(le+01)b
(le+00)b
-
(7e-02)b
-
-
-
(4e-01)b
-
-
le-02
Long-Term Action Levels
Rilk-Specific
Concentntioiu for
Carcinogencity
10-6 70-ye«r Risk
Otg/m3)
-
-
-
-
-
-
-
1 .5e-02c
-
-
6.3e-01
-
-
I.2e-01c
-
-
-
9.1e-OI
3.6e-03
-
-
-
-
-
-
RfC-Bued
Concentration* for
Non-Carcinogenic
Effects (Mg/m3)
-
-
-
400
50
0.1
0.3
-
20
1
-
1,000
400
-
10,000
1,000
-
70
-
-
-
400
-
-
10
Concentration!
Baaed on
Occupations]
Exposure
Lowest OEL/1000
Gig/m3)
180
25
20
1,780
67
0.23
5.90
4.30
4.80
3.00
7.60
0.20
--
0.30
-
--
5
5
22
1,900
303
152
710
300
12
Short-Term
Action Levels
Lowest OEL/100
Otg/m3)
1,800
250
200
17,800
670
2.30
59
43
48
30
76
2.00
-
3.00
-
-
50
50
220
19,000
3,030
1,520
7,100
3,000
120
-------
Table 4.
(Continued)
No.
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
Chemical
Carbon Telrachloride
Carbonyl Sulfide
Catechol
Chlorine
Chlorobenzene
Chlorodifluorome thane
Chloroform
Chloromelhyl methyl ether
Chloropentafluoroethane
Chloroprene
m-Cresol
o-Cresol
p-Cresol
Cyanogen
Cyclohexane
Cyclohexanol
Cyclohexanone
Cyclohexene
Cyclopentane
Diazomethane
Dibutyl-O-Phthalate
o-Dichlorobenzene
p-Dichlorobenzene
Dichloroelhylether
Dichlorodinuoromethane
CAS Number
56-23-5
463-58-1
120-80-9
7782-50-5
108-90-7
75-45-6
67-66-3
107-30-2
76-15-3
126-94-8
108-39-4
95-48-7
106-44-5
460-19-5
110-82-7
108-93-0
108-94-1
110-83-8
287-92-3
334-88-3
84-74-2
95-50-1
106-46-7
111-44-4
75-71-8
Carcinogenicily
Inhalation Unit
Risk 1/Olg/m3)
1.5e-05
--
--
--
-
--
2.3e-05
ND
-
-
NDe
NDe
NDe
-
-
--
-
--
-
-
-
-
(6.9e-06)b
3.3e-04c
-
Chronic
Toxicity8
Inhalation
RfC (mg/m3)
(2e-03)b
--
--
-
2e-02
--
(4e-02)b
-
-
le-03c
(2e-01)b
(2e-01)b
(2e-01)b
(le-01)b
--
-
-
-
-
-
(4e-01)b
2e-01
7e-01c
-
2e-01
Long-Term Action Levels
Risk-Specific
Concentration* for
Carcinogencity
10-6 70-year Risk
Otg/m3)
6.7e-02
-
-
-
-
-
4.3e-02c
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
1.4e-01
3.0e-03
-
RfC-Bated
Concentration* for
Non-Carcinogenic
Effect* (Mg/nt3)
2
-
-
-
20
-
40
-
-
1
200
200
200
100
-
-
-
-
-
-
400
200
700
-
200
Concentrations
Based on
Occupational
Exposure
Lowest OEL/1000
fttg/m3)
12.60
-
20
1.5
46
3,540
9.78
-
6,320
35
22
22
22
20
1,030
200
100
1,010
1,720
0.34
5.00
300
450
29
4,950
Short-Term
Action Levels
Lowest O EL/ 100
Oig/m3)
126
-
200
15
460
35,400
98
-
63,200
350
220
220
220
200
10,300
2,000
1,000
10,100
17,200
3.4
50
3,000
4,500
290
49,500
00
-------
Table 4.
(Continued)
No.
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
Chemical
1,1-Dichloroethane
1 ,2-Dichloroethanc
1,1-Dichloroelhylene
cis-1 ,2-dichlorocihylcnc
trans- 1 ,2-dichloroethylene
Dichloromethane
Dichloromonofluuroniethane
1 ,2-Dichloropropane
1 ,3-Dichloropropenc
l,2-Dichloro-l,l,2,2-Tetraf!uoroelhane
Dielhanolamine
Diethyl amine
N,N-Dimcthylaniline
Diethyl ether
Dimelhylamine
Dimethyl formannde
1 , 1-Dimelhyl hydrazine
2,4-Dinitrophenol
1,4-Dioxane
Diphenyl
Epichlorohydrin
1 ,2-Epoxybutane
Ethanol
Ethyl acetate
Ethyl acrylate
CAS Number
75-34-3
107-06-2
75-35-4
156-59-2
156-60-5
75-09-2
75-43-4
78-87-5
542-75-6
76-14-2
111-42-2
109-89-7
121-69-7
60-29-7
124-40-3
68-12-2
57-14-7
51-28-5
123-91-1
92-52-4
106-89-8
106-88-7
64-17-5
141-78-6
140-88-5
Carcinogenicity8
Inhalation Unit
Risk 1/Oig/m3)
NDe
2 6e-05
5e-05
-
-
4.7e-07
-
(1.9e-05)b
3.7e-05c
-
-
-
-
-
-
-
(2.5e-03)b
-
(3.1e-06)b
-
1 .2e-06c
-
-
-
(1.4e-05)b
Chronic
Toxicity*
Inhalation
RfC (mg/m3)
5e-01
-
(3e-02)b
(4e-02)b
(7-02)b
3e + 00c
-
-
2e-02c
-
-
-
-
-
-
3e-02
-
(7e-03)b
-
-
3e-04c
-
-
(3.0e + 00)b
-
Long-Term Action Levels
Risk-Specific
Concentrationi for
Carcinogeocity
10-6 70-year Risk
Oig/m3)
-
3.8e-02c
2.0e-02
-
-
2.1e-00
-
5.3e-02
2.7e-02
-
--
-
-
-
-
-
4.0e-04
-
3.2e-01
-
8.3e-01
-
-
-
7.1e-02
RfC'foted
Concentration* for
Non-Carcinogenic
Effects (Mg/m3)
500
-
30
40
70
3,000
-
-
20
-
-
-
-
-
-
30
-
7
-
-
0.3
-
-
3,000
-
Concentration!
Based on
Occupational
Exposure
Lowest OEL/1000
Oig/m3)
400
4.00
4.00
790
790
174
40
347
4.5
6,990
13
30
25
1,200
18
30
1
-
90
1.00
7.6
-
1,880
1,400
20
Short-Term
Action Levels
Lowest OEL/100
Olg/nO
4,000
40
40
7,900
7,900
1,740
400
3,470
45
69,900
130
300
250
12,000
180
300
10
-
900
10
76
-
18,800
14,000
200
-------
Table 4.
(Continued)
No.
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
Chemical
Elhyl aniinc
Elhylbenzene
Elhyl bromide
Ethyl carbamate
Ethyl chloride
Ethylenediamine
Ethylene dibromide
Ethylene glycol
Elhylene inline
Elhylene oxide
Formaldehyde
Formic Acid
Furan
Glycerol
n Heptane
n-Hexane
Hydra zine
Hydrochloric acid
Hydrogen cyanide
Hydrogen Sulfide
Isobiitanol
Isobutyl acetate
Isopropyl alcohol
Isopropyl amine
Isopropylbenzene
CAS Number
75-04-7
100-41-4
74-96-4
51-79 6
75-00-3
107-15-3
106-93-4
107-21-1
151-56-4
75-21-8
50-00-0
64-186
110-00-9
56-81-5
142-82-5
110-54-3
302-01-2
7647-01-0
74-90-8
7783-06-4
78-83-1
110-19-0
67-63-0
75-31-0
98-82-8
Carcinogenicity"
Inhalation Unit
Risk 1/CMg/m3)
-
-
-
-
-
-
2.2e-04c
-
-
I.Oe-04
1 .3e-05
-
-
-
-
-
4.9e-03c
--
-
-
-
-
-
-
-
Chronic
Toxic itya
Inhalation
RfC (mg/m3)
-
le-00
-
-
le + OI
(7.0e-02)b
-
(7.0e + 00)b
-
-
-
(7e + 00)
(4.0e-03)b
-
-
2e-0i
-
-
-
9e-04c
le + 00
-
-
-
9e-03c
Long-Term Action Levels
Risk -Specific
Concentration! for
Carcinogencity
10-6 70-year Risk
Oig/m3)
-
-
-
-
-
-
4.5e-03
-
--
l.Oe-02
7.7e-02
-
-
-
--
-
2.0e-04
-
-
-
-
-
-
-
-
RfC-Baud
Concentrations for
Non-Carcinogenic
Effecti Olg/m3)
-
1,000
-
-
10,000
70
-
7,000
-
-
-
7,000
4
-
-
200
--
-
-
0.9
1,000
-
-
-
9
Concentrations
Based on
Occupational
Exposure
Lowest OEL/1000
(Mg/m3)
18
434
22
--
2,600
25
-
125
0.88
1.80
0.37
9.00
-
5.00
1,600
i76
0.13
7.5
11
14
150
700
980
12
245
Shott-Tenn
Action Levels'1
Lowest O EL/ 100
(Mg/m3)
180
4,340
220
-
26,000
250
-
1,250
8.80
18
3.70
90
-
50
16,000
i.760
1 3
75
110
140
1,500
7,000
9,800
120
2,450
t J
O
-------
Table 4.
(Continued)
No.
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
Chemical
Melhanol
Methyl acetate
Methyl acrylate
Methyl amine
Methyl bromide
Methyl-tert-butyl-elher
Methyl chloride
Methylcyclohexane
Methyl-ethyl-ketone
Methyl formate
Methyl hydrazine
Methyl iodide
Methyl-Isobutyl-Ketone
Methyl isocyanate
Methyl-Isopropyl-Kelone
Methyl mercaptan
Methyl melhacrylate
Methyl-n-Propyl-ketone
Alpha-methyl-styrene
Monoethanolamine
Morpholine
Naphthalene
2-Nitropropane
N-Nitrosodimelhylamine
N-Nitrosomorpholine
CAS Number
67-56-1
79-20-9
96-33-3
74-89-5
74-83-9
1634-04-4
74-87-3
108-87-2
78-93-3
107-31-3
60-34-4
74-88-4
108-10-1
624-83-9
563-80-4
74-93-1
80-62-6
107-87-9
98-83-9
141-43-5
110-91-8
91-20-3
79-46-9
62-75-9
59-89-2
Ca i c inogenic ity a
Inhalation Unit
Risk 1/Oig/m3)
-
-
-
-
-
--
1.8e-06
-
ND
-
(3.le-04)b
-
-
-
-
-
-
-
-
-
-
-
2.7e-03
1 .4e-02c
-
Chronic
Toxicity*
Inhalation
RfC (mg/m3)
(2e + 00)b
(4e + 00)b
(le-01)b
-
(6e-03)b
-
--
--
3e-01
-
-
-
8e-02
-
-
-
(3e-01)b
--
(2e-01)b
--
-
(le-02)b
2e-02c
-
-
Long-Term Action Levels
Risk-Specific
Concentration* for
Carcinogencity
10-6 70-year Risk
Gig/m3)
-
-
-
-
-
-
5.5e-OI
--
--
-
3.2c-03
-
-
-
-
-
-
-
-
~
-
-
3.7e-04
7.1e-05
--
RfC-Bawd
Concentrations for
Non-Ore inogenic
Effects (/ig/m3)
2,000
4,000
100
-
6
-
-
-
300
-
-
-
80
-
-
-
300
-
200
-
-
10
20
-
-
Concent rat ioni
Based on
Occupational
Exposure
Lowest OEL/1000
Gig/m3)
260
606
35
12
19
-
103
1,600
590
246
0.019
10
205
0.047
705
0.98
410
700
240
7.50
70
50
35
-
--
Short-Term
Action Levels
Lowest OEL/100
Oig/m3)
2,600
6,060
350
120
190
-
1,030
16,000
5,900
2,460
0 19
100
2,050
0.47
7,050
10
4,100
7,000
2,400
75
700
500
350
—
-
N)
-------
Table 4.
(Continued)
No.
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
14i
142
143
144
145
146
147
148
149
150
Chemical
n-Nonane
n-Octanc
n-Pentane
Phenanthrene
Phenol
Phosgene
Phosphine
Phthalic anhydride
Propane
1,2-Propancdiol
1-Propanol
beta-Propiolactone
Propionaldehyde
Propionic acid
n-Propyl-Acelale
Propyiene oxide
1 ,2-Propylenimine
Pyridine
Quinone
Styrene
1,1,1 ,2-Tetrachloro-2,2-Dinuoroethane
1 , 1 ,2,2-Tetrachloroe thane
Telrachloroethylene
Tetrahydrofiiran
Toluene
CAS Number
111-84-2
111-65-9
109-66-0
85-01-9
108-95-2
75-44-5
7803-51-2
85-44-9
74-98-6
57-55-6
71-23-8
57-57-8
123-38-7
79-09-4
109-60-4
75-56-9
75-55-8
110-86-1
106-51-4
100-42-5
76-11-9
79-34-5
127-18-4
109-99-9
108-88-3
Carcinogenicity8
Inhalation Unit
Risk 1/Otg/m3)
-
-
-
-
-
-
-
--
-
-
-
-
-
-
-
3.7e-06
-
-
-
5.7e-07
-
5.8e-05
5.2e-07
-
-
Chronic
Toxicilya
Inhalation
RfC (mg/m3)
-
-
-
-
(2e + 00)b
-
3e-05
(7e+00)b
-
6e + 00
-
-
-
-
-
3e-02
-
4c-03
-
(7e-01)b
-
-
(4e-02)b
-
2e+00c
Long-Term Action Levels
Risk-Specific
Concentrations for
Carcinogencity
10-6 70-year Risk
Oig/m3)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
2.7e-0i
-
-
-
1.8e+00
-
1 .7e-02
I.9e+00
-
-
RfC-Bised
Concentrations for
Non-Carcinogenic
Effects Oig/m3)
-
-
-
-
2,000
-
0.03
7,000
-
6,000
-
-
-
-
-
30
-
4
-
700
--
-
40
-
2,000
Concentrations
Based on
Occupational
Exposure
Lowest OEL/1000
Oig/m3)
1,050
1,400
1,770
0.20
19
0.4
0.4
6.00
1,800
-
492
1.5
-
30
835
48
5
15
0.4
213
4,170
6.90
170
590
375
Short-Term
Action Levels
Lowest OEL/100
Gig/m3)
10,500
14,000
17,700
2
190
4
4
60
18,000
-
4,920
15
-
300
8,350
480
50
150
4
2,130
41,700
69
1,700
5,900
3,750
N)
to
-------
Table 4.
(Continued)
No.
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
Chemical
p-Toluidme
1,1,1 -Trichloroflhane
1 , 1 ,2-Trichloroelhane
Trichloroethylene
Trichlorofluoromethane
1 ,2,3-Trichloropropane
1 ,1,2-Trichloro-l ,2,2-Trifluorocthane
Trielhylamine
Trifliiorobromoinelhane
1 ,2,3-Trimelhylbenzene
1 ,2,4-Trimethylbenzene
1 ,3,5-Trimethylbenzene
Vinyl acetate
Vinyl bromide
Vinyl-chloride
m-Xylene
o-Xylene
p-Xylene
CAS Number
106-49-0
71-55-6
79-00-5
79-01-6
75-69^
96-18^
76-13-1
121-44-8
75-63-8
526-73-8
95-63-6
108-67-8
108-05-4
593-60-2
75-01-4
108-38-3
95-47-6
106-42-3
Carcinogenicitya
Inhalation Unit
Risk 1 /Olg/m3)
(5.4e-05)b
-
1 .6e-05
1.7e-6
-
-
-
-
-
-
--
-
--
3.2e-05
8.4c-05
-
-
-
Chronic
Toxicitya
Inhalation
RfC (mg/m3)
-
l.Oe+00
(1.0e-02)b
-
7.0e-01
(2.0e-02)b
(2.7e + 01)b
-
-
-
-
-
2e-01
-
-
7.0e-01
7.0e-01
3.0e-01
Long-Term Action Levels
Risk-Specific
Concentrations for
Carcinogencity
10-6 70-year Risk
(Ag/m3)
1.9e-02
-
6.3e-02
5.9e-01
-
-
-
--
-
-
-
-
-
S.le-02
1.2e-02
-
-
-
RfC-Baied
Concentrations for
Non-Carcinogenic
Effects (Mg/m3)
-
1,000
10
-
700
20
27,000
-
-
-
-
-
200
-
-
700
700
300
Concentrations
Based on
Occupational
Exposure
Lowest OEL/1000
Olg/m3)
8.80
1,900
45
269
5,620
60
7,600
40
6,090
123
123
123
30
20
2.60
434
434
434
Short-Term
Action Levels
Lowest OEL/100
Olg/m3)
88
19,000
450
2,690
56,200
600
76,000
400
60,900
1,230
1,230
1,230
300
200
26
4,340
4,340
4,340
K)
OJ
INSTRUCTIONS ON USE:
Read short-term action level directly from last column. For the three columns of long-term action levels, use the 10-6 risk data, if available, then the RfC data; use the OEL/1000 if
no other data exists.
a EPA does not necessarily endorse the use of oral slope factors or oral RfDs to derive inhalation values. These are intended to serve as screening levels only and do not represent EPA
guidance.
Derived based on oral slope factor (or oral RfD).
'' Verified, available on IRIS or Workgroup concurrence on final database file, and IRIS input pending.
EPA does not necessarily endorse the use of occupational exposure limits to derive short- and long-term action levels for ambient air. These are intended to serve as screening levels
only and do not represent EPA guidance. Intended changes for OEL values are included, where applicable.
e EPA Class C or D carcinogen.
-------
developing cancer in a lifetime as a result of the exposure in question. Equation 6
assumes continuous exposure (24 hours/day, 365 days/year for 70 years) to the estimated
annual average concentration in air.
R = (Ca)(IUR) (Eq. 6)
R is the cancer risk from long-term exposure to a specific VOC in air,
dimensionless; Ca is the annual average ambient concentration estimated from Equation
5, //g/m3; IUR is the inhalation unit risk factor, (^g/m3)"1 obtained from Table 4.
If the source operates for less than 70 years, multiply Ca by x/70, where x
is the expected operating time of the source in years before using Equation 6. If more
than one VOC is present, the cancer risks for each VOC can be summed to derive the
total cancer risk at a specified distance downwind of the source.
Non-Cancer Effects Due to Long-Term Exposure
Non-cancer effects can be evaluated by using chronic inhalation reference
concentrations (RfCs). An inhalation RfC is the an estimate (with uncertainty spanning
perhaps an order of magnitude) of continuous exposure to the human population that is
likely to be without appreciable risk of deleterious effects during a lifetime. RfCs for a
limited number of compounds are available in IRIS and HEAST.
If inhalation RfCs were not available from either IRIS or HEAST, then
chronic oral reference dose (RfD) data (in mg/kg/day) were multiplied by 70 kg
(average body weight of an adult), then divided by 20 m3/day (average adult inhalation
rate), and finally multiplied by 1000 ^g/mg to derive a value in /ig/m3.
Ambient air action levels based on extrapolated oral data should be used
cautiously. Before extrapolating data an array of factors should be assessed on a
compound by compound basis to determine the feasibility of route-to-route
24
-------
extrapolations. Important factors include the absorption, distribution, metabolism and
excretion of the compound; portal of entry effects; acute and chronic toxicities, and other
information.
For compounds lacking RfC or RfD values, action levels were based on
occupational exposure levels recommended by the Occupational Safety and Health
Administration (OSHA)11 and the American Conference of Governmental Industrial
Hygienists (ACGIH)12. The action levels were estimated by using the lower of the
OSHA Permissible Exposure Limit-Time Weighted Average (PEL-TWA) level (or
ceiling value) or the ACGIH Threshold Limit Value - Time Weighted Average (TLV-
TWA) level (or ceiling value). The lower value was divided by 1000 to compensate for
differences between occupational and residential exposures.
Long-term ambient air action level concentrations for non-carcinogens
based on RfCs, extrapolated RfDs and occupational exposure levels for 168 compounds
are also listed in Table 4. The action levels are in units of ,ag/m3 to facilitate
comparison to the ambient air concentrations estimated from Equation 5.
Short-Term Exposure
The short term (one hour) action levels, in /^g/m3, are presented in the last
column of Table 4. The listed values were obtained by dividing the lowest of (1) the
OSHA PEL-TWA or (2) the ACGIH TLV-TWA (or ceiling limits if 8-hour averages are
not available) by 100. Division by 100 accounts for variations in human sensitivity
(occupational levels are designed to protect healthy adult workers) and for uncertainties
in using occupational exposure levels to derive ambient air action levels.
The occupational exposure levels on which the short-term action levels are
based are subject to change. To check the values in Table 4 (or to derive values for
compounds not listed in Table 4), determine the current OSHA PEL-TWA values by
25
-------
consulting 29 CFR Section 1910 and the most recent edition of the ACGIH publication
entitled Threshold Limit Values and Biological Exposure Indices.
The short-term action levels listed in Table 4 can be compared directly
with the estimated maximum hourly ambient air concentrations obtained by using
Equation 2 and the appropriate figure (2, 3, or 4). Use of the short term action levels
should consider that no EPA accepted method exists to determine the short-term
concentrations of airborne chemicals acceptable for community exposure.
EXAMPLE
The following steps illustrate the use of the estimation procedures
presented in this document. The goal is to estimate the maximum hourly and annual
average ambient air concentrations at the nearest receptor to the SVE system and
compare these values to the action level concentrations listed in Table 4.
Step 1 For this example, assume a site that has approximately 10,000 m3
of soil contaminated with chloroform, 1,1,1-trichloroethane, and
trichloroethylene at concentrations in the soil of 100, 10,000, and
1,000 ug/g, respectively. The volume of contaminated soil is not
known with any certainty. The bulk density of the soil at the site
averages about 1.5 g/cm3. During pilot-scale tests the respective
vapor-phase concentrations of chloroform, 1,1,1-trichloroethane,
and trichloroethylene in the extracted air was 100,000, 10,000,000,
and 500,000 ug/m3 (all three compounds are present at below
their saturated level given in Appendix A). The size of the SVE
system to be installed has not yet been determined, nor has the
need for air emission controls, so a medium size SVE system with
an 85 m3/min (3000 cfm) air extraction rate and no air emission
controls is assumed. The system is expected to be in continual
operation for 6 months (1.58 x 107 seconds). The nearest off-site
downwind receptor is 400 meters away.
26
-------
Step 2 Estimate the total emissions potential for the site. Using Equation
1 and assuming 100% of the contamination is to be removed, the
maximum average emission rate of chloroform would be:
ER=
100
100
Step 5
(1.58 x 107)
= 0.095 g/sec
The maximum average emission rate for 1,1,1-trichloroethane is
9.5 g/sec, and for trichloroethylene is 0.95 g/sec.
Step 3 Estimate the emission rate of each compound. The pilot-scale
data are used as inputs to Equation 2 along with the assumed
flowrate of 85 m3/min. For chloroform, the emission rate would
be:
ER = (100,000)(85/60)(l
-------
Table 5.
Estimated Emission Rates and Ambient Air Concentrations
Chloroform
1, 1, 1-Trichloroethane
Trichloroethylene
Vapor-Phase
Concentration
For Example
Problem
(^g/m3)
100,000
10,000,000
500,000
Emission Rate
(g/s)
0.14
14
0.71
Ambient Concentrations
(^g/m3)
Maximum
Hourly
35
3,500
180
Annual
Average
0.88
88
4.4
Table 6.
Action Level Concentrations
Chloroform
1,1, 1-Trichloroethane
Trichloroethylene
Table 4 Action Levels /ig/m3
Short-Term
98
19,000
2,690
Long-Term
0.0431
1,0002
0.591
on 10"6, 70-year risk.
2Based on reference dose concentrations (RfCs).
28
-------
Using Equation 5, the annual average ambient air concentration
for chloroform would be:
Ca = (0.14)(6.25) = 0.88 ug/m3
Step 6 Compare the downwind concentrations to the action level ambient
air concentrations. The short-term and long-term action levels
from Table 4 for the compounds of interest are presented in
Table 6. None of the estimated maximum hourly ambient
concentrations exceed the applicable action levels. The annual
average ambient concentrations, however, exceed the long-term
action levels for both chloroform and tnchloroethylene, by a factor
of 20 and 10 respectively.
Step 7 Document the results of the air pathway analysis and define a
future course of action. Based on these screening level results, a
more rigorous analysis of the air impacts is warranted. This would
most likely involve refining the emission rate, dispersion, and
health risk estimates. The emission rate estimate could be
improved by using the actual or proposed operating conditions
(e.g. exhaust gas rate) or by making field measurements at the
SVE system. The dispersion estimates could be improved by using
a less conservative model (e.g. EPA's Industrial Source Complex
model) and site-specific meteorological conditions. The health
risk estimate could be improved by using the expected operational
lifetime of the SVE system rather than assuming a 70-year
exposure. If the more rigorous analysis still indicates that adverse
air impacts may occur, then the addition of air emission controls
or altering the operating conditions to control emissions (e.g.
exhaust gas rate or hours of operation per day) should be
considered.
29
-------
CONCLUSIONS
The procedures presented here are not intended to negate the need for
rigorous analyses that consider site specific meteorological conditions and the health
effects of the specific compounds involved. Although the procedures are based on what
is typical and reasonable for cleaning up Superfund sites, the underlying assumptions
need to be kept in mind. Emission models assume steady-state conditions, dispersion
models assume Gaussian distribution of the plume contaminant concentration, and many
of the health levels are not endorsed by the Environmental Protection Agency. EPA's
Regional Toxicologist should be contacted for general lexicological information and
technical guidance on evaluation of chemicals without established toxicity values.
ACKNOWLEDGEMENTS
Jawad Touma and Norman Huey of EPA contributed to the overall
direction of this project. The health effects sections were prepared in consultation with
Fred Hauchman of EPA.
30
-------
REFERENCES
1. Eklund, B., S. Smith, and M. Hunt. Estimation of Air Impacts For
Air Stripping of Contaminated Water. EPA-450/1-91-002. May
1991.
2. Pedersen, T.A. and J.T. Curtis. Handbook of Soil Vapor
Extraction Technology. EPA/540/2-91/003. 1991.
3. Johnson, Stanley, Kemblowski, Byers, and Colthart. A Practical
Approach to the Design, Operation, and Monitoring of In-Situ
Soil-Venting Systems. Ground Water Monitoring Review. pp!59-
178. Spring 1990.
4. Thompson, P., A. Inglis, and B. Eklund. Emission Factors for
Superfund Remediation Technologies. EPA-450/1-91-001. March
1991.
5. Screening Procedures for Estimating the Air Quality Impact of
Stationary Sources. EPA-450/4-88-010, Research Triangle Park,
NC August 1988, NTIS PB89-159396.
6. Jim Malot of Terra Vac. Personal Communication. 1991.
7. Michael Sink of PES. Personal Communication. 1991.
8. Neil Hutzler of Michigan Tech. Personal Communication. 1991.
9. Nancy Metzer of Roy F. Weston. Personal Communication. 1991.
10. Health Effects Assessment Summary Tables (HEAST). U.S.
Environmental Protection Agency, Wash. D.C., Fourth Quarter,
1990, OERR 9200.6-303(91-1), NTIS No. PB91-92199, January
1991.
11. 29 CFR ch. XVII. Subpart Z. Section 1910.1000. July 1, 1990.
12. 1990-1991 Threshold Limit Values for Chemical Substances and
Physical Agents and Biological Indices. American Conference of
Governmental Industrial Hygienists, Cincinnati, Ohio, 1990.
31
-------
APPENDIX A
PHYSICAL AND CHEMICAL CONSTANTS
FOR SELECTED COMPOUNDS
-------
APPENDIX A - PHYSICAL PROPERTY DATA
No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
Organic Compound
Aceuldehyde
Acetic acid
Acetic anhydride
Acetone
Acctonitrile
Acrolein
Acrylic acid
Acryionitrile
Ally! alcohol
Ally! chloride
Aniline
Anthracene
Benzaldehyde
Benzene
Benzole acid
Benzyl alcohol
Benzyl chloride
Bromoform
1,3-Butadiene
N-Butane
2-Butano!
N-Butanol
N-Butyl-Acetate
Tert-Butvl-Alcohol
Carbon disulfidc
Carbon tetrachlohde
Carbonyl sulfide
Catechol
Chlorine
Chlorobenzene
Chlorodifluoromethanc
Chloroform
Chloromethyl methyl ether
Chloropemafluoroethane
Chloroprene
M-Crcsol
O-Cresol
P-Cresol
Cyanogen
Cyclohexane
Cyclohexanol
Cyclohexanone
Cyclohexene
CAS NO.
75-074)
64-19-7
108-24-7
67-64-1
75-05-8
107-02-8
79-10-7
107-13-1
107-18-6
107-05-1
62-53-3
120-12-7
100-52-7
71^3-2
65-85-0
100-51-6
100-44-7
75-25-2
106-99-0
106-97-8
15892-23-6
71-36-3
123-8^4
75-65-0
75-15-0
56-23-5
463-58-1
120-80-9
7782-50-5
108-90-7
75-45-6
67-66-3
107-30-2
76-15-3
126-99-8
108-39-4
95^8-7
106-44-5
460-19-5
110-82-7
108-93-0
108-94-1
110-83-8
Formula
C2H4O
C2H4O2
C4H6O3
C3H6O
C2H3N
C3H4O
C3H402
C3H3N
C3H6O
C3H5CL
C6H7N
C14H10
C7H6O
C6H6
C7H6O2
C7H8O
C6H5CH2C1
CHBr3
C4H6
C4H10
C4H10O
C4H10O
C6H12O2
C4H10O
CS2
CCL4
COS
C6H4(OH)2
C12
C6H5CL
CHCLF2
CHCL3
C2H5CIO
C2CLF5
CH2CHCH2C1
C7H8O
C7H8O
C7H80
C2N2
C6H12
C6H120
C6H100
C6H10
Molecular
Weight
(g/g-mol)
44.00
60.06
102.09
58.08
41.06
56.1
72.1
53.06
58.08
76.53
93.13
178.23
106.12
78.12
122.12
108.14
126.6
252.77
54.09
58.12
74.12
74.12
116.16
74.12
76.13
153.82
60.1
110.1
70.9
112.56
86.47
119.38
80.51
154.47
7653
108.14
108.14
108.14
52.04
84.16
100.16
98.14
82.15
Vapor
Pressure
(mm Hg)1
760
15.41
5.266
266
90
244.2
5.2
114
23.3
368
1
1.3E-06
1
95.2
0.00704
0.15
1.21
5.6
2100.00
1820
10
6.5
15
0.17
366
113
-
-
-
11.8
-
208
-
-
273
0.08
0.24
0.11
3980
100
1.22
4.8
-
Saturated
Vapor Cone.
Oig/m3)1
1.80E+09
4.97E + 07
2.89E-t-07
8.30E+08
1.99E-KK
7.36E+08
2.02E+07
3-25E-KB
7.27E+07
1-51E+09
5.01E+06
1.25E+01
5.70E+06
4.00E+08
4.62E+04
8.72E+05
8-23E+06
7.61E+07
6.09E+09
5.69E + 09
3.98E+07
2.59E + 07
9.37E+07
6.77E+05
1 JOE + 09
9.34E + 08
-
-
-
7.14E+07
-
1.33E + 09
-
-
1.12E+09
4.65E+OS
1.40E + 06
6.39E + 05
1.11E + 10
4J2E + 08
6J7E + 06
2^3E + 07
-
-------
Appendix A.
(Continued)
No.
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
Organic Compound
Cyclopentane
Diazomethane
Dibutyi-O-Phthalate
O-Dichlorobenzene
P-Dichlorobenzene
Dichloroethyiether
Dichlorodifluoromethane
1,1-Dichloroethane
1,2-Dichloroethane
1,1-Dichloroethylene
cis-l^-Dichloroethyiene
trans-l,2-Dichlorocthylene
Dichloromethane
Dichloromonofluoromethane
1,2-Dichloropropane
1,3-Dichloropropene
1.2-Dichloro-l,l,2,2-Tetrafluoroethane
Diethanolamme
Diethyl amme
N,N-Dimethyiamline
Dielhyl ether
Dimethylamme
Dimethyl formamide
1,1-Dimethy) hydrazme
2,4-Dinitrophenol
1,4-Dioxanc
Diphenyl
Epichlorohydrin
1,2-Epoxybutane
Ethanol
Ethyl acetate
Ethyl acrylate
Ethyl ammc
Ethylbenzcne
Ethyl Bromide
Ethyl carbamate
Ethyl Chlonde
Ethylenediamme
Ethylene dibromide
Ethylene glycol
Ethylene imme
CAS NO.
287-92-3
334-88-3
84-74-2
95-50-1
106-46-7
111-44-4
75-71-8
75-34-3
107-06-2
75-35-4
156-59-2
156-60-5
75-09-2
75-43-4
78-87-5
542-75-6
76-14-2
111-42-2
109-89-7
121-69-7
60-29-7
124-40-3
68-12-2
57-14-7
51-28-5
123-91-1
92-52-4
106-89-8
106-88-7
64-17-5
141-78-6
140-88-5
75-04-7
KXM1-4
74-96-4
51-79-6
75-00-3
107-15-3
106-93-4
107-21-1
151-56-4
Formula
C5H10
CH2N2
C16H22O4
C6H4CL2
C6H4CL2
C4H8C12O
CCL2F2
C2H4CL2
C2H4CL2
C2H2CL2
C2H2CL2
C2H2CL2
CH2CL2
CHCL2F
C3H6CL2
C3H4C12
C2CL2F4
C4H11NO2
C4H11N
C8H11N
C4H10O
C2H7N
C3H7NO
C2H8N2
C6H4N2O5
C4H802
C12H10
C3H5C1O
C4H8O
C2H6O
C4H8O2
C5H8O2
C2H7N
C8H10
C2H5Br
C3H7NO2
C2H5CI
C2H8N2
C2H4Br
C2H6O2
C2II5N
Molecular
Weight
(g/g-mol)
70.13
42.04
278.35
147.00
147.00
143.02
120.91
98.96
98.96
96.94
96.94
96.94
84.93
102.92
112.99
110.98
170.92
105.14
73.14
121.18
74.12
45.08
73.09
60.10
184.11
88.11
154.21
92.53
72.0
46.07
88.11
100.12
45.08
106.16
108.97
89.09
6451
60.10
187.88
62.07
43.07
Vapor
Pressure
(mm Hg)1
317.44
_
l.OOE-05
1
1.2
1.4
4870
234
80
600
208
324
362
1360
42
43
_
_
350@35C
_
440@20C
563 @ OC
4.0
157
53.8
37
_
17
—
50
100
40
1057
10
-
10
1200
10.7
14
0.13
-
Saturated
Vapor Cone.
(ug/rn3)1
1 JOE +09
_
_
7.90E + 06
9.48E+06
! OS^ . *, . ••
3.16E+10 I
U4E+09
4.26E+08
3.13E+09
1.08E+09
1.69E+09
1.65E+09
7.52E+09
2.55E + 08
2.57E+08
_
_
USE + 09
_
1.75E + 09
1.36E+09
1J7E + 07
5.07E + 08
5.32E + 08
USE + 08
_
8.45E + 07
—
1.24E + 08
4.74E+08
2.15E+08
2.56E+09
5.71E + 07
—
4.79E + 07
4.16E + 09
3.46E + 07
1.41E + 08
4.34E + 05
-
-------
Appendix A.
(Continued)
No
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
Organic Compound
Ethytene oxide
Formaldehyde
Formic acid
Furan
Glycerol
N-Heptane
N-Hexane
Hydrazine
Hydrochloric acid
Hydrogen cyanide
Hydrogen sulfide
Isobutanol
Isobutyl acetate
Isopropyl alcohol
Isopropyl amme
Isopropylbenzene
Methanol
Methyl acetate
Methyl acrylatc
Methyl amme
Methyl bromide
Methyl-tert-butvl -ether
Methyl chloride
Methylcyclohexane
Methyl-ethyl-ketone
Methyl formate
Vlethyi hydrazinc
Methyl iodide
Vlethyl-Isobutyl-Ketone
Methyl isocyanate
Methyl-lsopropyl-Ketone
Methyl mercaptan
Methyl methacrylate
Methyl-N-Propyl-Ketone
Alpha-Methyl-Styrene
vlonoetnanolamme
Vlorpholine
Naphthalene
-Nitropropane
N-Nitrosodimethylamme
•J-Nitrosomorpholme
CAS NO.
75-21-8
50-00-0
64-18-6
110-00-9
56-81-5
142-82-5
110-54-3
302-01-2
7647-01-0
74-90-8
7783-064
78-83-1
110-19-0
67-63-0
75-31-0
98-82-8
67-56-1
79-20-9
96-33-3
74-89-5
74-83-9
1634-04-4
74-87-3
108-87-2
78-93-3
107-31-3
60-34-4
74-88-4
108-10-1
624-83-9
563-80-4
74-93-1
80-62-6
107-87-9
98-83-9
141-43-5
110-91-8
91-20-3
79-46-9
62-75-9
59-89-2
Formula
C2H40
CH2O
CH2O2
C4H4O
C3H8O3
C7H16
C6H14
H4N2
HC1
CHN
H2S
C4H10O
C6H12O2
C3H8O
C3H9N
C9H12
CH4O
C3H6O2
C4H7O2
CH5N
CH3BR
C5H12O
CH3CL
C7H14
C4H8O
C2H4O2
CH6N2
CH3I
C6H120
C2H3NO
C5H10O
CH4S
C5H8O2
C5H10O
C9H10
C2H7NO
C4H9NO
C10H8
C3H7NO2
C2H6N20
C4H8N2O
Molecular
Weight
(g/g-raol)
44.06
30.03
46.03
68.08
92.09
100.2
86.18
32.05
36.46
27.03
34.08
74.12
116.16
60.1
59.11
120.19
32.04
74.08
86.09
31.06
94.94
88.15
50.49
98.19
72.11
60.05
46.07
141.94
100.16
57.05
86.13
48.1
100.10
86.13
118.18
61.08
87.12
128.19
89.09
74.08
116.11
Vapor
Pressure
(mm Hg)1
1250
3500
42
596
1.60E-04
46
150.3
14.4
32,450
_
15,200
10
..
42.8
460
10.9@40C
114
235
_
770@-6C
_
245
3830
43
100
500
49.6
91
19.31
348
15.7
_
39
_
0.076
_
10.08
0.023
12.9
_
-
Saturated II
Vapor Cone.
(Mg/nt5)1
2.96E + 09
5.65E+09
1.04E + 08
2.18E+09
7.92E + 02
2.48E+08
6.96E+08
2.48E+07
6J6E-HO
_
2.78E+10
3.98E+07
—
138E+08
1.46E+09
7.04E-I-07
1.96E+08
9.36E+08
_
1.29E + 09
_
1.16E + 09
1.04E + 10
2.27E + 08
3.88E+08
1.61E + 09
1.23E+08
-
1.04E+08 ||
1.07E + 09
7.27E+07
_
2.10E+08
_
4.83E + 05
4.72E+07
USE + 05
6.18E + 07
_
-
-------
Appendix A.
(Continued)
No.
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
Organic Compound
N-Nonane
N-Octane
N-Pentane
Phenanthrene
Phenol
Phosgene
Phosphine
Phthalic anhydride
Propane
1,2-Propanediol
1-Propanol
beta-Propiolactone
Propionaldchyde
Propionic acid
N-Propyl-Acetate
Propylene oxide
1,2-Propyienimine
Pyridine
Quinone
Styrene
l,l,l,2-Tetrachloro-2,2-Difluoroetriane
1 , 1 ,2,2,-Te trachloroethane
Tetraehloroethylene
Tetrahydrofuran
Toluene
P-Toluidine
1,1.1-Trichloroethane
1,1,2-Trichioroethane
Trichloroethylene
Tnchlorofluoromethane
1,2.3-Trichloropropane
1.1.2-Trichloro-l,2.2-Trinuoroethane
Triethylamme
Tnnuorobromomethane
1 .2,3-Trimethylbenzene
1.2,4-Trimethylbenzene
1.3,5-Trimethylbenzene
Vinvl Acetate
Vinvl bromide
Vinvl-Chloridc
M-Xvlene
CAS NO.
111-84-2
111-65-9
109-66-0
85-01-8
108-95-2
75^4-5
7803-51-2
85-44-9
74-98-6
57-55-6
71-23-8
57-57-8
123-38-7
79-09-4
109-60-4
75-56-9
75-55-8
110-86-1
106-51-4
100-42-5
76-11-9
79-34-5
127-18-4
109-99-9
108-88-3
106-49-0
71-55-6
79-00-5
79-01-6
75-69^
96-18-4
76-13-1
121-44-8
75-63-8
526-73-8
95-63-6
108-67-8
108-05^
593-60-2
75-01-1
108-38-3
Formula
C9H20
C8H18
C5H12
C14H10
C6H6O
CC12O
H3P
C8H4O3
C3H8
C3H8O2
C3H8O
C3H4O2
C3H6O
C3H6O2
C5H10O2
C3H6O
C3H7N
C5H5N
C6H4O2
C8H8
C2CL4F2
C2H2CL4
C2CL4
G4H8O
C7H8
C7H9N
C2H3CL3
C2H3CL3
C2HCL3
CCL3F
C3H5CL3
C2CL3F3
C6H15N
CBRF3
C9H12
C9H12
C9H12
C4H6O2
C2H3Br
C2H3CL
C8H10
Molecular
Weight
(g/g-mol)
128.26
114.23
72.15
178.23
94.11
98.92
34.00
148.11
44.1
76.11
60.1
72.06
58.08
74.08
102.12
58.08
54.1
79.1
108.09
104.15
203.83
167.85
165.83
72.11
92.14
107.16
133.41
133.41
131.4
137.37
147.43
187.38
101.19
148.91
120.19
120.19
120.19
86.09
107.0
623
106.2
Vapor
Pressure
(mm Hg)1
4.28
17
513
2.00E-04
0.0341
U94
2,000
0.0015
760
0.3
20.85
3.4
300
10
35
524J
112
20
—
7.3
-
6.5
19
72.1
30
0.3
123
25
75
667
3.1
300
400
-
-
-
1.86
115
895
2660
8
Saturated
Vapor Cone.
(Mg/m3)1
2.95E+07
1.04E+08
1.99E+09
1.92E+03
1.72E+05
7.41E+09
3.66E+09
1.19E+04
1.80E+09
-
6.74E+07
132E+07
9.37E+08
3.98E+07
1.92E+08
1.64E-t-09
3.26E+08
8.50E+07
-
4.09E + 07
-
5.86E-I-07
1.69E + 08
2.79E + 08
1.49E + 08
1.73E + 06
8.82E + 08
1.79E + 08
5 JOE +08
4.92E+09
2.46E+07
3.02E + 09
2.18E+09
-
-
-
1.20E+07
5.32E + 08
5.15E + 09
8.94E-I-09
4.57E + 07
-------
Appendix A.
(Continued)
No.
167
168
Organic Compound
O-Xylene
P-Xylene
CAS NO.
95-47-4
106-42-3
Formula
C8H10
C8H10
Molecular
Weight
(g/g-mol)
106.2
106.2
Vapor
Pressure
(mm Hg)1
7
9.5
Saturated
Vapor Cone.
Og/m3)1
4.00E+07
5.42E+07
1 All vapor pressures are at 25 C unless otherwise indicated.
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