AP4222
SUPPLEMENT NO. 2
FOR
COMPILATION
OF AIR POLLUTANT
EMISSION FACTORS
SECOND EDITION
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Water Programs
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina
September 1973
-------
INSTRUCTIONS
FOR INSERTING SUPPLEMENT NO. 2
INTO
COMPILATION OF AIR POLLUTANT EMISSION FACTORS
1. Replace pages 111 - iv dated 7/73 with pages in - iv dated 9/73.
2. Replace undated pages 1 - 2 with pages 1 - 2 dated 9/73.
3. Replace pages 3.1.1-5 - 3.1.1-8 dated 4/73 with pages 3.1.1-5 - 3.1.1-8 dated 9/73.
4. Replace pages 3.1.2-1 - 3.1.2-8 dated 4/73 with pages 3.1.2-1 - 3.1.2-8 dated 9/73.
5. Replace pages A-l - A-2 dated 4/73 with pages A-l - A-2 dated 9/73.
ii
9/73
-------
PREFACE
This document reports data available on those atmospheric emissions for which sufficient information exists to
establish realistic emission factors. The information contained herein is based on Public Health Service
Publication 999-AP-42, Compilation of Air Pollutant Emission Factors, by R. L. Duprey, and on a revised and
expanded version of Compilation of Air Pollutant Emission Factors that was published by the Environmental
Protection Agency in February 1972. The scope of this second edition has been broadened to reflect expanding
knowledge of emissions.
Chapters and sections of this document have been arranged in a format that permits easy and convenient
replacement of material as information reflecting more accurate and refined emission factors is published and
distributed. To speed dissemination of emission information, chapters or sections that contain new data will !>(
issued separate from the parent report whenevei they are leviscd
To facilitate the addition of future materials, the punched, loose-leaf formal was selected. This .ippnuic!'
permits the document to be placed in a three-ring binder or to be secured by rings, rivets, or other fa
-------
ACKNOWLEDGMENTS
Because this document is a product of the efforts of many individuals, it is im-
possible to acknowledge each individual who has contributed. Special recognition
is given, however, to Environmental Protection Agency employees M. J. McGraw,
A. J. Hoffman, J. H. Southerland, and R. L. Dupre-y for their efforts in the pro-
duction of this work. Bylines identify the contributions of individual authors who
revised specific sections and chapters.
Issuance Release Date
Compilation of Emission Fdctorx. Second Edition 4/73
Supplement No. 1
Section 4.3. Srorj.ije of Petroleum Products 7/73
Section 4.4, Marketing and Transportation of Petroleum Products
Supplement No. 2
Introduction
Section 3.1. Highwjv Vehicles
Appendix. Table A-l 9/73
9/73 iv
-------
COMPILATION
OF
AIR POLLUTANT EMISSION FACTORS
INTRODUCTION
In the assessment of community air pollution, there is a critical need for accurate data
on the quantity and characteristics of emissions from the numerous sources that contribute
to the problem. The large number of individual sources and the diversity of source types
make conducting field measurements of emissions on a source-by-source basis at the point
of release impractical. The only feasible method of determining pollutant emissions for a
given community is to make generalized estimates of typical emissions from each of the
source types.
One of the most useful (and logical) tools for estimating typical emissions is the "emis-
sion factor, " \vhich is an estimate of the rate at which a pollutant is released to the atmos-
phere as a result of some activity, such as combustion or industrial production, divided by
the level of that activity (also expressed in terms of a temporal rate). In other words, the
emission factor relates the quantity of pollutants emitted to some indicator (activity level)
such as production capacity, quantity of fuel burned, or vehicle miles traveled. In most
cases, these factors are simply given as statistical or estimated averages; that is, no em-
pirical information on the various process parameters (temperature, reactant concentra-
tions, etc. ) is considered in their calculation. However, for a few cases, such as in the
estimation of hydrocarbon emissions from petroleum storage tanks, precise empirical for-
mulas relating emissions to such variables as tank diameter, liquid storage temperature,
and wind velocity have been developed. Because of their superior precision, emission fac-
tors based on empirical formulas are more desirable to obtain and can usually be given the
highest accuracy rating. Factors derived from statistical averages, however, if based on
an adequate number of field measurements ("source tests"), can also be both precise and
accurate within practical and useful limits.
An example should illustrate how the factors are to be used:
Suppose a sulfuric acid plant, with a production rate of 200 Ions/day of 100 percent acid,
operates at an overall SC^ to SO-j conversion elficiency of 97 percent. Using the formu-
la given as a footnote to Table 5.17-1 on page 5. 17-5 of this publication, the uncontrolled
sulfur dioxide emissions can be calculated:
9/73 1
-------
SC>2 emissions = [ -13, 65 (% conversion efficiency) + 1365] x production rate
= [ -13. 65 (97%) + 1365] Ib/ton acid x 200 tons acid/day
= 40 Ib/ton acid x 200 tons acid/day
= 8000 Ib/day (3632 kg/day)
The emission factors presented in this report have been estimated using a wide spectrum
of techniques available for their determination. The preparation/revision of each factor
section involves, first of all, the search for and obtainment of all the known -written infor-
mation on that source category from such sources as the Air Pollution Technical Information
Center literature, Environmental Protection Agency technical reports (including emission
test reports), and the National Emissions Data System point source file. After these data
are reviewed, organized, and analyzed, the process descriptions, process flowsheets, and
other background portions of the section are prepared. Then, using the compiled informa-
tion, representative emission factors are developed for each pollutant emitted by each point
source of the process category. As stated above, these factors are usually obtained by
simply averaging the respective numerical data obtained. When feasible, the ranges in the
factors are presented for further clarity. Occasionally, enough data exist to permit the
development of either empirical or theoretical formulas (or graphs) relating emissions fac-
tors to various process parameters such as stream temperature, sulfur content, or catalyst.
In these cases, representative values of these process parameters are selected and substi-
tuted into the formulas or graphs that, in turn, yield representative emission factors which
are then tabulated within. The pertinent formulas and graphical data are also included in
the section to allow the estimation of emission factors when the process conditions differ
from those selected by the author(s).
After the draft of a section is completed, it is circulated for technical review to various
personnel routinely familiar with the emission aspects of the particular activity. After these
review comments are obtained and evaluated, the final draft is written and submitted for
editing and publication.
The limitations and applicability of emission factors must be understood. To give some
notion of the accuracy of the factors for a specific process, each process has been ranked
as "A, " "B, " "C, " "D, " or "E, " For a process -with an "A" ranking, the emission factor
should be considered excellent, i. e. , based on field measurements of a large number of
sources. A process ranked "B" should be considered above average, i. e. , based on a lim-
ited number of field measurements. A ranking of "C" is considered average; "D, " below
average; and "E, "poor. These rankings are presented below the table titles throughout the
report.
The reader must be herein cautioned not to use these emission factors indiscriminately.
That is, the factors generally will not permit the calculation of accurate emissions measure-
ments from an individual installation. Only an on-site source test can provide data suffi-
ciently accurate and precise to use in such undertakings as the design and purchase of control
equipment or the initiation of a legal action. Factors are more valid when applied to a large
number of processes, as, for example, when emission inventories are conducted as part of
community or nationwide air pollution studies.
EMISSION FACTORS 9/73
-------
3.1.1 Average Emission Factors for Highway Vehicles by David S. Kircher
and Charles C. Masser
3.1.1.1 General - Emission factors in this section update emission factors for gasoline-powered motor vehicles
presented in the February 1972 Compilation of Air Pollutant Emission factors.' These new factois are based on
nationwide statistical data for light-duty, gasoline-powered vehicles; heavy-duty, gasoline-powered vehicles; and
heavy-duty, dicsel-powercd vehicles Average emission factors arc intended to assist those individuals
interested in compiling approximate emission estimates for large areas, such as an individual state or the nation.
The emission factor calculation techniques presented in sections 3.1.2 through 3.1.7 of this chapter are strongly
recommended for the formulation of localized emission estimates required for air quality modeling or for the
evaluation of air pollutant control strategies.
3.1.1.2 Emissions Average emission factors by calendar year based on statistical data for the United States are
presented in Table 3.1.1-1. These factors were calculated using the techniques described in sections 3.1.2, 3.1.4,
and 3.1.5 of this chapter. Because the majority of highway vehicle emissions are produced (on a nationwide basis)
by gasoline-powered light-duty vehicles and heavy-duty, gasoline- and diesel-powered vehicles, these are the only
vehicles considered in Table 3.1.1-1. The emission contribution from diesel-powered, light-duty vehicles, from
gaseous-fucl-powered vehicles, and from motorcycles is assumed to be insignificant for the purpose of developing
these appioximate factors.
The exhaust emission values presented in Table 3.1.1-1 for carbon monoxide, hydrocarbons, and nitrogen
oxides are for an average speed of approximately 19.6 mi/hr (31.5 km/hr). These values can be modified to make
them representative of the area for which emission estimates arc being prepared, by using the average speed
adjustment factors contained in Figure 3.1.1-1. For example, if carbon monoxide emissions in 1970 are to be
estimated for a state where the average speed is 35 mi/hr, the appropriate emission factor would be 0.6 times 78
or 47 grams per mile. This value would then be multiplied by the total vehicle miles of travel (VMT) to arrive at a
carbon monoxide emission estimate.
Crankcase and evaporative hydrocarbons, participate, and sulfur oxide emission factors are average values that
can be considered independent of speed. Emission estimates for these pollutants are calculated by simply multi-
plying the VMT by the emission factor.
Note: The emission factor data presented for highway vehicles in this chapter are based on a generalized test
cycle that involves operation typical of every-day driving patterns. Because this drivrng cycle is intended to
represent typical driving, it cannot apply in specific instances, i.e. to a particular segment of a particular roadway
at a particular time. In order to estimate vehicular emissions under a specific set of conditions, "modal" emission
factor data are icquired. Driving modes include: idle, constant speed, acceleration, and deceleration. Because all
driving patterns can be divided into one of these four modes, emissions can be determined by summing the modal
emissions for a particular driving pattern.
The Environmental Protection Agency is currently evaluating the use of modal emission data. Emission data
for idle, various constant speeds, and various initial and final speeds (accelerations and decelerations) are being
collected and analyzed. It is anticipated that these data will be published in Sections 3.1.2 and 3 1.4 in subse-
quent revisions of this publication Modal data for light-duty vehicles (Section 3.1.2) will be published during
1973, and data for heavy-duty gasoline vehicles will be published at a later date.
9/73 Internal Combustion Engine Sources 3.1.1-5
-------
10
co
f 1
(/)
H
1
CO
LU
i
o
i
2.
Z
O
O
LU
CO
00
LU
(J
I
LU
g
g
o:
O
CO
o
o
LL
O
CO
CO
LU
LU
o
LU
ro
CD
CO
CN
^ 00
^ 1
o
03
CD
CU
oo ;
CD 1
"^
0
X
LU
"CN
c 0
-|Z
O TJ oo
" x ro
z °d<
^ c
QJ '-^
t/) CD
8 o
oo ^ Q.
C C «3
_g ^i_ CD
03
0
I tn
13
X
LU
c -§
O y
ro C
oo
en
E
O!
E
CD
E
en
E
en
E
en
£
CD
-
-a
E
D)
E
0>
E
en
F
en
J
en
ro
CD
CNJOJCNCNCNCNCNCMCNICNCNICNCN
OOOOOOOOOOOOO
OOOOOOOOOOOOO
CMCMCNtNCNCSJCMCNCMCNCNCNICM
OOOOOOOOOOOOO
CNCNICNCNCSiCNCNCMCNCMCSICNCM
OOOOOOOOOOOOO
OOOOOOOOOOOOO
CNtNCMCNCMCSJCMCNCNCNCNICNCNI
OOOOOOOOOOOOO
CNrslCNJCNCNICMCNICNCSICNCMCSICN
OOOOOOOOOOOOO
oooococooooooocooooooooooo
OOOOOOOOOOOOO
O^^^^r^or^r^or-
roconronrorococNicsiCNT-^
^^^.^^.^ooo^oo^^co
^LnLnLfjLnLnun^'3-roron'-
CO T- CM CN CN ro <*
COCNCN---OOOOOOO
c^o r*« c*o oo
LOMMfNCNCN-r-^OOOO
(--coLn^co^^r^coor-Lnoo
Ln^^^-nrococNCNCsi <-o
rNicocsicD'-LnO.cor-CNr-.M-tn
or^r-cDcoiniD^-cnrocNjCN^
IT)
O^ 00 *}" CO CN CO ^D "^ ^^ ^~ ^*" ^^ C^
oo r^ r^ to co \ci LO ^f co co CNI CN ^~
O5 O) O} C7) O) O^ O} O} O) O^ O^ O5 O^
c
o
-a
c
c
o
c
o
o
CU
00
03
Q_
LU
Hi
LU
I-
O
3.1.1-6
EMISSION FACTORS
9/73
-------
20
AVERAGE ROUTE SPEED, km/hr
40 60 80
100 120
1.5
CC
o
o
a:
1.0
cc
cc
o
o
a
UJ
LU
0.5
- NOTE: CURVES DEVELOPED FROM TESTS OF PRE-1968 (UNCONTROLLED) VEHICLES. RECENT -
TESTS INDICATE THEIR APPROXIMATE APPLICABILITY TO CONTROLLED VEHICLES INCLUDING
THOSE EQUIPPED WITH CATALYTIC DEVICES. UPDATED CURVES ARE PLANNED IN FUTURE
- ADDITIONS TO THIS DOCUMENT.
0
15
60
30 45
AVERAGE ROUTE SPEED, mi/hr
Figure 3.1.1-1. Average speed correction factors for all model years.5-7
9/73
Internal Combustion Engine Sources
3.1.1-7
-------
References for Section 3.1.1
1. Compilation of Air Pollutant Emission Factors. U.S. Environmental Protection Agency, Office of Air Pro-
grams. Research Triangle Park, N.C. Publication Number AP-42. February 1972.
2. Highway Statistics 1970. U.S. Department of Transportation, Federal Highway Administration Washington.
D.C. 1971.
3. Census of Transportation Truck Inventory and Use Survey. U.S. Department of Commerce, Bureau of the
Census. Washington, D.C. July 1970.
4. Automotive Facts and Figures. Automobile Manufacturers Association. Washington, D.C. July 1970.
5. McMichael, W.F. and A.M. Rose, Jr. A Comparison of Emissions from Automobiles in Cities at Two Different
Altitudes. U.S. Department of Health, Education and Welfare, Public Health Service. Cincinnati. Ohio. July
1965.
6. Study of Emissions from Light-Duty Vehicles in Six Cities. Automotive Environmental Systems Inc. San
Bernadmo, Calif. Prepared for the Environmental Protection Agency. Research Triangle Park, N.C.. under
Contract Number 68-04-0042. June 1972.
7. Walsh, M.P., Unpublished data on emissions from a catalyst-equipped light duty vehicle. The City of New
York Department of Air Resources, Bureau of Motor Vehicle Pollution Control. New York, N.Y. November
1972.
3.1.1-8 EMISSION FACTORS 9/73
-------
3.1.2 Light-Duty, Gasoline-Powered Vehicles by David S. Kirclier
and Charles C. ,W;),s.ser
3.1.2.1 General Because of their widespread use, light-duty, gasohnc-poweied highway vehicles uie responsible
for a large percentage of the total emissions from highway vehicles on a nationwide as well as on a icgionwidc
basis. The information contained in this section permits the calculation of emission factors for this class of
highway vehicles operated in a specific geographic area undei study. Section 3.1.1 provided geneiah/ed emission
factors for all highway vehicles combined; this section provides the information necessary to calculate emission
factors for one class of vehicles by using the technique outlined below.
3.1.2.2 Carbon Monoxide, Hydrocarbon, and Nitrogen Oxide Emissions The calculation of light-duty vehicle
exhaust emission factors for carbon monoxide, hydrocarbons, and nitrogen oxides can be expressed
mathematically as:
n+ 1
enp = H q d; nij Sj (1)
i = n
where: e = Emjsslon factor in grams pci vehicle mile for calendar year (n), and pollutant (p)
Cj = The 1975 Federal test procedure emission rate for pollutant (p) in g/mi for the itn model year
at low mileage 1 '2
d[=The controlled vehicle pollutant (p) emission deterioration factor for the i'"1 model year
at calendar year (n)
nij=The weighted annual travel of the i"1 model year during calendar year (n) The detemnnation
of this variable involves the use of the vehicle model year distribution
Sj =The weighted speed adjustment factor for the i"1 model year vehicles
In addition to exhaust emission factors, the calculation of hydrocarbon emissions from gasoline motor vehicles
involves evaporative and ciankcase hydrocaibon emission tales. Evaporation and crankcase emissions can be
determined using:
n + 1
fn= E Iviij (2)
i = n-l 2
where: fn = The combined evaporative and ciankcase hydrocarbon emission factor for calendar year (n)
hj = The combined evaporative and crankcase emission rate for the rn model year
m, = The weighted annual travel of the i"1 model year during calendar year (n)
A brief discussion of each of the variables presented in the above equations is necessary to help clarify their
formulation and use. These discussions amplify the definitions at the beginning of the chapter.
Test cycle emission rates (c and h). A recent study of light-duty vehicle exhaust emission rates in six cities
resulted in the data for 1971 and earlier model years that arc presented in Tables 3.1.2-1 and 3.1 2-2.3 Emission
9/93 Internal Combustion Engine Sources 3.1.2-1
-------
ro
LU
LU O
Q D
xt
0 J
H <
LU
(2 z
o g
oc i
5°
z z
a <
<°<
z. -1
25i
a: co f:
I
T °
1 > <
UJ 1- LL
D 3 2
x 2 o
O t co
2 5 52
0-5
^_ 1 ^^
2 -1 LU
Z ^
op
m "
CC C/3
< EC
U O
00
^ ^
CM <
LL
Ivl Z
00 r?
1 "Hj
"8
E
0)
a.
CD
cn
CD
cu
E
^
_0
actors at
M
C
o
(/>
trt
1
0)
trt
-3
CO
JZ
X
1 1 1
*-<"
i/> CD
o r«.
a. cn
O
r>-
<5>
cn
CO
o
CO
CO
o
OD
CO
o
cu
aZ
c t;
.2 ro
*- ti
to ^
0?^
-1 ro Q.
CO Tf
00 «- CM T-
*^ r- O O
CO
cn CM CM <-'
r~- r~-
cn CN CM ^
O5 00
* »- CN ^
CO CM
CO CM
CD CN CO CM
CO CN
sr rv
cn it ^r CM
CO CM
in oo
CD O5 * CM
»t CN
oq in
r^ ^ co m
oo in
,, «
~ c
cu M o J3
"° -o Is
~i cn ^
B r= X »- U
i|§o._E-o._
1 .8 o^|^ >^=|
5 y ro E~S)O)Xj; cno)
o g o LU
i £
«- O5
CO *-
CD CD
cq q
CM "d-
CN i-1
CO *
CM t-^
CO O
^ CO
00 O
«* CO
«- CM
in co
in ^~
tri co
CO P-.
<^ CM'
CO CM
CO CM
t/> r
QJ ^t^
1 -s S
0 ^ ^
3 cn
C -M r-
0) _ 'J= .= C
2 E I "15
| «|.S «
X _
co *3- r: cn
oo » _ CM T- co "r-;
^ T- C) CD CD CD
00 «- CM ? CO CO
<-: *-: CD CD *- o
r^
co «-; ^r oq
O CM T-^ » T-^ CD
CM «-
r^
cn o ^f co
CM CO ^ CO « CD
^r CM
U) O «-; O5
CN CO rf CO CO <-'
«d- CM
CO CO <-; O3
in r-~ in co co ^
r^ <*
<-; CO CO r-.
CN in co co CM' t
r^ re
^- "* co CD
co o in co CN ^
Q;
c -a
E x
"0 IS °
^ t
X -t-*O c
o ._ E S 2 ._ E & - E
§ E|^ ^.^4 2^4
E"cn~c7iXji"a)"ai O)cn
o c
0. U
f .^ Z
^ > Q)
« » >
« ^ TJ
u 7; o>
lie
m
|52
S 5 g
E 2 ^
0 ~ £
Do"3
C CD ,-
= 15;
s -
O o O
in C *
i > "O
' CD C
. .n ro
! w 8 <"'
: _a; | -D
: O C m
Q_
LU
S o o <"
1^ &e
c CD x: -
g ra c £
o ^ e c1
E cu .. DC
0) -C O c
~a
£ S
c m
g -Q
o
c _
<» 0>
CD
<- c
o o
~ UJ l_ (- Tl
!r, <- « E S
Q. UJ £T OQ
UJ
I-
O
3.1.2-2
EMISSION FACTORS
9/73
-------
LU 5
U
u
rf
o y
EC I
* > 2
iiTt;
9g
Ii
i =
<
6
z
~
CD
13
o
CD
Q.
CD
nj
CD
E
3
_g
CT3
0)
0
fj
O
CD
C
CD
in
CO
03
00
CD
CD
P~-
CD
03
CD
CD
03
CD
OT
T
CD
C
cu
D
"o
O_
co tf
00 T- CN «-
^ ^ 0 CD
CO «3-
00 r- CM <-
<-: r^ CD CD
CO PS. CO CM
CN r-' CD CD
P~ r-.
O3 CM Csi ^
P-- PS,
O) CN CM T-^
O3 00
<* t- CM T-^
CO CN
CO CM
CO CN CO CM
CO CM
^ ^
CO CM
in co
CD en ^' csi
>lt CM
CD O3
O « <* CN
LO CO
O P~
i- CM CD CO
LO CO
00 LO
PS. ^f CO If)
00 LO
c.
o
CD -Q
c 1 - E « § .- E
! ;i CT) Ol -C- >. c^ CD
CJ LU
r- O)
CO T-
CD CD
CO
^ CO
«-' CD
CO
r- CD
T-' O
Csi ^
LO CM
CO CM
LO CM
CO CM
«- CSI
LO co
LO tf
LO CO
CO PS.
'd- Csi
"*. *~
CO CM
CO Csi
CD CN
CO Csi
CD
'rr
O
III
+j Ol CD
2
ra O
JC
I-
_O> ^)
TD
£Si
5 c e
£
S T3
fs;
o ;T "9
S8
Q_
UJ
to
^
c
c
CN
w
CD
CJ
tt)
a
QC
CO
c
fO
a>
w.
(D
D
XI
CT5
03
^
E
5
O
CO
^
O
C
results ar
01
.0
(D
0)
CO
2
OJ
Q.
O
tn
CO
CO
L-
c
0
$
E
(U
(U
£
5
O
E
OJ
O9
if
E
5
-
o
g.
^
c
o
ro
0)
CD
c
o
TD
3!
03
.Q
CD
present
Estimat
"E
(O
T3
C
to
M
C
O
(fl
E
0)
E
*C
01
c
O)
.c
w
estimates
c
o
1
cc
«-
o
c
Q)
CO
(U
-C
H
LT)
tj
C
OJ
0)
'GJ
DC
c
estimates
c
0
-o
S
CO
CD
CJ "O
CD
*~
C
.2
o
_c
J3
O
1
LLJ
t-
O
~Z.
9/73
Internal Combustion Engine Sources
3.1.2-3
-------
Table 3.1.2-3. LIGHT-DUTY VEHICLE
CRANKCASE AND EVAPORATIVE HYDROCARBON
EMISSIONS BY MODEL YEAR FOR
ALL AREAS EXCEPT CALIFORNIA3
EMISSION FACTOR RATING: C
Model
year
Pre-1963
1963 through 1967
1968 through 1970
1971
1972
Post- 1972
Hydi ocai bons
g/mi
7 1
3.8
30
05
0.2
0.2
g/km
4.4
2.4
1 9
0.3
0 1
0 1
a Reference 7.
Table 3.1.2-4. LIGHT-DUTY VEHICLE
CRANKCASE AND EVAPORATIVE HYDROCARBON
EMISSIONS BY MODEL YEAR FOR
CALIFORNIA3
EMISSION FACTOR RATING: C
Model
year
Pre-1961
1961 through 1963
1964 through 1967
1968 through 1969
1970 through 1971
1972
Post- 1972
Hydrocarbons
9/mi
7 1
3.8
3.0
3.0
0.5
02
02
g/km
4.4
2.4
1.9
1 9
03
0.1
0.1
a Reference 7.
3.1.2-4
EMISSION FACTORS
9/73
-------
rates for 1972 and later vehicles in these tables are based primarily on the applicable California and Federal
emission standards. These standards were modified to reflect low-mileage emission rates using information
provided in the references.^ Reference 4 also provided the information necessary to modify the 1971 and
earlier test results to low-mileage emission rates. Evaporative and crankcase hydrocarbon emission values are
shown in Tables 3.1.2-3 and 3.1.2-4. Test cycle emission rates are presented for both low and high altitudes
(exhaust emissions) and for California and all areas except California (exhaust, evaporative, and crankcase
emissions). High-altitude areas are considered separately because of the significant impact altitude has on carbon
monoxide, hydrocarbon, and nitrogen oxide exhaust emissions. California is considered separately because
emission control standards were implemented there on a different and somewhat more acceleiated schedule than
were the Federal emission standards.
Deterioration factors (d). Exhaust deterioration factors for emission controlled vehicles by model year and
pollutant are presented in Tables 3.1.2-5 and 3.1.2-6. Deterioration factors enable the modification of low
mileage emission rates to account for the ageing or deterioration of exhaust emission control devices. The
deterioration rates presented were derived primarily from testing done by the California Air Resources Board.4
Weighted annual mileage (m). The determination of the weighted annual mileage is best illustrated by the
example in Table 3.1.2-7. In this example, the model year distribution as of July 1 (in this case nationwide) is
combined with nationwide annual travel by model year, unless localized annual mileages by model year are
available. In the calculation of city-specific emission factors, the model year distribution for the area under
consideration should be obtained from registration statistics and combined with the annual mileages as in Table
3.1.2-7.
Weighted speed adjustment factor (s). The weighted speed adjustment factor enables the calculation of a region-
wide emission factor that takes into account variation in average route speed. This variable is calculated using:
n
Sj = £ fjVj (3)
where: Sj = The weighted speed adjustment factor for the i"1 model year
f; = The fraction of total annual vehicle miles traveled at speed (j)
v: = The vehicular average speed correction factor for average speed (j)
The values for the vehicular speed adjustment factor (v) are contained in Figure 3.1.1-1.
3.1.2.3 Paniculate and Sulfur Oxide Emissions Light-duty, gasoline-powered vehicles emit relatively small
quantities of participate and sulfur oxides in comparison with the three pollutants discussed above. For this
reason, average rather than calculated emission factors should be sufficiently accurate for approximating.
particulate and sulfur oxide emissions from light-duty, gasoline-powered vehicles. Average emission factors for
these pollutants are presented in Table 3.1.2-8. No Federal standards for these two pollutants are presently in
effect, although many areas do have opacity (antismoke) regulations applicable to motor vehicles.
9/73 Internal Combustion Engine Sources 3.1.2-5
-------
li
2 o "3,
Q u> S
oc Q <
0 ^ !r
O CQ
rr _ UJ
§ -I O
5 cr X
XO
x cc
x o
UJ 1-
- o
UJ <
Q £
2 O >
2 CC Q
UJ UJ
<% I- CC
^ uj LLJ
O Q g
..: co O
f uj a.
CN Q
CO
o
o
T~
0
o
"
o
o
o
o
o
o
o
0
o
o
o
o
o
0
o
o
Carbon
monox .'.'
Pre-1& .
CM CM CD 03 CN
px 00 in CO CN
t t * f~ CN
i-~ CD «- co O
co r^ in co »-
r- T- ,- r- CN
co in o to O
CD r^ in in o
CO » P~ CD CO
in r- <* ^r CO
co co * -=r m
in CD ^f xj" PX
r-~ co o co CM
^f CD "xf ^f CD
r- CD 03 CO O
CO
CD
i
CL
O
c
CD
O)
CD
CD
t
c
'o
^
OJ
7JJ
"co
l_
0
VI
CO
E
CD
CD
"£
C
C
o
(D
g
CD
CD
Q
C
0
03
O
+j
1s
~^
GJ
y
CD
T3
Q)
a
e
CD
E
o
c
CD
CO
C
o
o
%
CO
CD
CD
-C
§
l-
o
o
^
__
o
CD
U
jr
CD
CO
O)
CD
T3
O
o
O
O
c/>
3
CD
^_,
QJ
C
0
-£,
I1
CD
00
in
CD
-------
z
LU
gli
1- S
7 -1
2 0
Q V)
2 ^
< 0
7"
CO 3 ro
DC Q <
< h- i
Q -J t
10 <
co tg 2
< ^ «g
- o I
Q < I"
U y. >
Xf n
Z O a.
8 tt
cc 2
0 Q
(£ CO
i ^J
o co in co co
CD CN n LO co
CD LO O^ r*** CO
CD CN1 c\j ^f co
o <* co r- o>
o CM CM «a- in
o «- co LO co
O CM r- CO in
O «- «- CM «t
§0000
o o o o
-0
§ ° V CO CD CD CO
^ § £ 05 CD 05 C35
LC5 CM OCOCMCOCOCM
*~
In r- OCOCMCOCMCM
r- CM ^^<-t-T-r-
O O OCMCOOCOCM
1T5 O OCO'-COCMCM
^- CM r- r- *- ^ r- r-
*3- CO OCO'-CMCMCM
^f m orouocDcor^
«3- C*- OCMCNICN«-
rj- CD OCSI«-CMCM*-
co o OLncNr-coco
co in o CM ^ CM «- i-
CM «* OCNIOCOCDO
CO CO O CM » t T »
^ r- O»-Or-T-O
o o oooooo
o o oooooo
Ol CT
D "D c D
or^-l 8<-corxcocjor-
rxfflto o icocDCDcor-05
^H *~ £ ~o £i T 2-2-22'~
p
CM
CD
O5
CO
CO
^~
r~;
cq
in
^
o
CO
?
o
CD
^1 QJ
V) O)
o o
Q. *-
§to co co
c\4 CNJ c*J
CO LO ^^" ^^
q CN CM CM
O CM CM CM
O CM «-_ r-
* r~ V T
o c\ «-. »-.
O CM '-.'-;
O O O O
O CM <-_«-_
o^oo
° *~ ° °.
o o o o
o o o o
cu
O)
^
en
05 ^
^5 2J O5 O) O5
«
o
O5
"
CO
CO
s
CO
-_
o
0
T)
CO
C7i
o
rv
- w
nj
ui -^
QJ <1>
U >
Is
"D x:
"o *-
t; o
C CD
O fj
cc
11
*- ti
2 a
£ c
iS
"O c
OJ C
Q. QJ
9- o
D .C
C O
"5 Q
s §
^
*" o
CD CD
V "°
^ g
s s
OJ "D
> _
ID
01.Q
£ S
in ro ^
It!
t ^ CO
8 o e
C in O
CU _5 k~
ra O
a
E
S
C
CO
CT5
C
OJ
CO
JZ
£
o
U
CO
c
CD
>
XI
C
D
L>
U
CO
c
c
!»
cu
m
to
Q;*
U
c
CO
cause of poor mainter
hides.
OJ
CJ
0)
>
CO
cu
>
"HJ
-D
0
C
O
f^.
CD
O
H-
-3
in
0)
to
Q)
C
CD
U
cc
ID
>
CD
T)
e
CD
p-
CD
LD
r^-
en
ototype
w
CD
c
o
o
CD
(C
fdctors 1
c
0
o
B «
Q "o
2 1
° s
5 >
2 «
< *
^ "^
npub 1 1 sh
Cahforn
3
§ 83
sed on Reference 5 an
ased on test results for
£ m
T CU
9/73
Internal Combustion Engine Sources
3.1.2-7
-------
Table 3.1.2-7. SAMPLE CALCULATION OF WEIGHTED LIGHT-DUTY VEHICLE
ANNUAL TRAVEL3
Age,
years
Oe
1
2
3
4
5
6
7
8
9
10
11
12
>13
Fraction of total
vehicles in use
nationwide (a)"
0.000
0.078
0.116
0.110
0.098
0.106
0.106
0.088
0.078
0.063
0.041
0.035
0.021
0.060
Average annual
miles driven (b)c
1 5,900
15,900
15,000
14,000
13,100
1 2,200
11,300
10,300
9,400
8,500
7,600
6,700
6,700
6,700
a x b
0
1,240
1,740
1,540
1,284
1,293
1,198
906
733
536
312
235
141
402
Annual
travel (m)d
0.000
0.107
0.151
0.133
0.111
0.112
0.104
0.078
0.063
0.046
0.027
0.020
0.012
0.036
References 8 and 9.
bThese data are for July 1, 1970, from Reference 8 and represent the US population of light-
duty vehicles by model year.
GMileage values are the results of at least squares analysis of data in Reference 9.
Xab
eRefers to "next" year's models introduced in the fall
Table 3.1.2-8. PARTICULATE AND SULFUR OXIDES
EMISSION FACTORS FOR LIGHT-DUTY,
GASOLINE-POWERED VEHICLES
EMISSION FACTOR RATING: C
Pollutant
Particulate3
Exhaust
Tire wear
Sulfur oxidesb
(SOX as S02)
Emissions
g/mi
0.34
0.20
0.13
g/km
0.21
0.12
0.08
a R eferences 10, 11, a nd 12.
Based on an average fuel consumption of 13.6 mi/gal
(5.8 km/liter) from Reference 8 and on the use of a
fuel with a 0.032 percent sulfur content from Refer-
ences 13 through 15, and a density of 6 1 Ib/gal
(0.73 kg/liter) from References 1f! i-.J ' "
EMISSION FACTORS
9/73
------- |