United States
Environmental Protection
Agency
National Risk Management
Research Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/SR-02/076
August 2004
&EPA Project Summary
Emissions of Organic Air Toxics
from Open Burning
Paul M. Lemieux
Emissions from open burning, on a
mass pollutant per mass fuel (emission
factor) basis, are greater than those
from well-controlled combustion
sources. Some types of open burning
(e.g., biomass) are large sources on a
global scale when compared with other
broad classes of sources (e.g., mobile
and industrial sources). A detailed lit-
erature search was performed to col-
lect and collate available data on
emissions of airborne toxic organic
substances from open burning sources.
Data available in the literature varied
according to the source and class of
air toxics of interest. Volatile organic
compound (VOC) and polycyclic aro-
matic hydrocarbon (PAH) data were
available for many of the sources. Data
on emission of semivolatile organic
compounds (SVOCs) that are not PAHs
were available for several sources. Car-
bonyl and polychlorinated dibenzo-p-di-
oxin and polychlorinated dibenzofuran
(PCDD/F) data were available for only a
few sources, and there were several
sources for which no emissions data
were available at all. Several observa-
tions were made from the available data.
• On a mass emitted per mass
burned basis, less VOCs were typi-
cally emitted from biomass open
burning sources than from those
with anthropogenic fuels, particu-
larly fuels containing polymers.
• Biomass open burning sources typi-
cally emitted less SVOCs and PAHs
than anthropogenic sources, on a
mass emitted per mass burned ba-
sis. Burning pools of crude oil and
diesel fuel produced significant
amounts of PAHs relative to other
types of open burning, and PAH
emissions were highest when com-
bustion of polymers was taking
place.
• Based on very limited data, biom-
ass open burning sources typically
produced higher levels of carbon-
yls than anthropogenic sources on
a mass emitted per mass burned
basis, probably due to oxygenated
structures resulting from thermal
decomposition of cellulose.
• It must be noted that local burn con-
ditions could significantly change
these relative levels.
• Based on very limited data, PCDD/F
emissions varied greatly from
source to source and exhibited sig-
nificant variations within source
categories. This high degree of
variation is likely due to a combina-
tion of factors, including fuel com-
position, fuel heating value, bulk
density, oxygen transport, and com-
bustion conditions. This highlights
the importance of having accept-
able test data for PCDD/F emis-
sions from open burning to better
quantify contributions of those
sources to the overall PCDD/F emis-
sions inventory.
This Project Summary was developed
by the National Risk Management Re-
search Laboratory's Air Pollution Pre-
vention and Control Division, Research
Triangle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
-------
Introduction
The purpose of the report is to 1) enu-
merate types of open burning activities
and the availability of organic air toxics
emissions data; 2) identify methodologies
for developing open burning air toxics
emissions data, including methods for
measuring emissions and converting the
data into forms useful for emissions in-
ventory development and source emis-
sions comparisons; 3) compare emissions
of different organic air toxic pollutants
within open burning source classifications
on a per mass of material burned basis;
and 4) compare emissions of different
organic air toxic pollutants from open burn-
ing in general on a per mass of material
burned basis.
A detailed literature search was per-
formed to collect and collate available
data on emissions of organic air toxics
from the target open burning sources
listed in Table 1. Data available in the
literature varied according to the source
and the class of air toxics of interest. Vola-
tile organic compound (VOC) and polycy-
clic aromatic hydrocarbon (PAH) data
were available for many of the sources.
Data on emission of non-PAH semivolatile
organic compounds (SVOCs) were avail-
able for several sources. Carbonyl and
Table 1. Open Burning Sources
Accidental Fires
Agricultural Crop Residues
Agricultural Plastic Film
Animal Carcasses
Automobile Shredder Fluff
Camp Fires
Car/Boat/Train Fires (cargo excluded)
Construction Debris
Copper Wire Reclamation
Crude Oil and Oil Spill Fires
Electronic Waste
Fiberglass
Fireworks
Grain Silo Fires
Household Waste
Land Clearing Biomass Debris
Landfills/Dumps
Prescribed Burning/Savanna/Forest Fires
Structural Fires
Tire Burning
Yard Waste Burning
polychlorinated dibenzo-p-dioxin and poly-
chlorinated dibenzofuran (PCDD/F) data
were available for only a few sources,
and there were several sources for which
no emissions data were available at all.
Summary and data analysis
Table 2, the summary of available data,
shows that some of the targeted sources
covered in the report are better charac-
terized than others, some are poorly char-
acterized, and some are not characterized
at all. Thus, data available in the litera-
ture permits comparison of only 10 of the
original 21 target source categories. Be-
cause the collected data is not a robust
set, it is not possible to directly compare
speciated organics as a whole from the
various sources. Rather, the report com-
pares sources by selecting certain key
pollutants within general pollutant classes.
Measurements of these key pollutants
within sources were averaged so that a
single value could be used for that source.
Where sufficient data are available, error
bars have been added to illustrate the
range of emission values for that source.
Benzene, toluene, ethyl benzene, xy-
lenes, and styrene are the key pollutants
selected for comparison of VOCs. They
are commonly produced during combus-
Table 2. Summary of Available Data
luded
Pollutant
VOCs
SVOCs/PAHs
Carbonyls
Total PCDDs/Fs
TEQ' PCDDs/Fs
Total PCBs
TEQ PCBs
ing/Savanna,
c
m
T3
0)
ol
X
X
X
X
X
i Residues
LJ.
O
O
(0
o
b)
X
X
X
X
X
iomass Debr
m
D)
c
(0
1 s
CD m
w o
-5; oj ro
jfe \~
^ o (P
"SEE
ro ro c
>• O <
X
CO
0)
iZ
'o.
W
n <"
w (D
T3 .^
C Ll_
ra
6 |
1 1
0 <
X
X
X
X
1 1
2 Q
° w
1 1
x .5
X
X
X
X
X
X
X
D)
c
'c
m
0)
F
X
X
8=
[Z
OJ
T3
T3
0)
W
utomobile
<
X
X
X
iberglass
LJ_
X
X
E
iZ
o
to
ra
CL
S
o
b)
X
X
in
0)
ii~
tructural F
w
o
D)
TO
^
in
0)
LJ_
c
'ra
ar/Boat/Tr
o
j5
-------
tion processes, and data were available
for most of the ten comparison sources.
Figure 1 shows the relative quantities of
these key VOCs produced across those
comparison sources for which data were
available. The biomass sources gener-
ally had less VOC emissions than the
other sources. In particular, sources with
significant amounts of polymer plastics
(automobile shredder residue, fiberglass)
produced fairly prodigious amounts of
VOCs, approaching percent levels of the
initial material mass. Pesticide bags, al-
though made from plastics, did not show
emissions as high as other sources con-
taining large quantities of plastics. It is
possible that ambient air influx was suffi-
cient in the pesticide bag experiments to
allow more efficient combustion of the
material.
For the SVOCs, naphthalene,
benzo[a]pyrene, and total non-naphtha-
lene PAHs were chosen for comparison.
It must be noted that, for agricultural burn-
ing, naphthalene was not included be-
cause of the reference's authors' doubts
on the quality of the data. Figure 2 com-
pares the emissions of the selected key
SVOCs from the various sources. As was
the case with the VOCs, the combustion
of biomass produced less SVOCs than
combustion of various man-made prod-
ucts. Pool fires of liquid fuels produced
significant amounts of PAHs, but tire fires
and combustion of fiberglass produced
the most. Tire fires produced nearly 100
mg of benzo[a]pyrene per kg of tire com-
busted.
The available data for carbonyls is
much more limited, so formaldehyde was
chosen as the only compound for com-
parison between sources. Figure 3 illus-
trates the relative emissions of
formaldehyde from open burning. Al-
though the data set is much more limited
than for VOCs and SVOCs, it shows that
combustion of biomass produced signifi-
cantly more formaldehyde than the other
open burning sources. This is likely due
to the high levels of elemental oxygen
bound within the cellulose structures
found in biomass.
Emissions of PCDDs/Fs showed sig-
nificant differences between somewhat
similar sources. As can be seen in Figure
4, open burning of agricultural residues
such as wheat and rice straw produced
almost two orders of magnitude less
PCDDs/Fs per kg of material burned than
forest fires, on both a total and a TEQ
basis. Open burning of household waste
in barrels shows similar emissions to that
of forest fires. Automobile shredder resi-
due emitted several orders of magnitude
higher PCDDs/Fs than any of the other
100,000
-------
sources, likely due to the smoldering
combustion that occurred during the fluff
combustion experiments. This is consis-
tent with the backyard burning experi-
ments, which found that higher levels of
PCDDs/Fs were produced during the
smoldering combustion stage than dur-
ing flaming combustion. Automobile
shredder fluff contains significant
amounts of copper (from shredded elec-
trical components) and chlorine (from vi-
nyl seat cushions), which are consistent
with formation of PCDDs/Fs. Given the
high degree of inter- and intra-source vari-
ability, it is not likely that PCDD/F emis-
sions could be estimated with even a
poor degree of certainty without the pres-
ence of test data.
10,000
.
Q.
ra
, E
E-
o ra
=! <1)
< a:
'o
to
-------
10 1
in
a
a
o
a.
0.01 -
0.001 -
0.0001
w
Q
Q
o
CL
o
Figure 4. PCDDs/Fs from Open Burning Sources (mg/kg material burned)
The EPA author, Paul M. Lemieux is also the EPA Project Officer (see below).
The complete report, entitled "Emissions of Organic Air Toxics from Open Burn-
ing, " is available at httprfmm.epa.gov/appcdwww/aptb/EPA-600-R-02-076.pdf
or as Order No. PB2004-106605; Cost: $31.50, subject to change from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161-0001
Telephone: (703) 605-6000
(800) 553-6847 (U.S. only)
The EPA Project Officer can be contacted at:
Air Pollution Prevention and Control Division
National Risk Management Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711-0001
-------
United States
Environmental Protection Agency
CenterforEnvironmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use
$300
EPA/600/SR-02/076
PRESORTED STANDARD
POSTAGES FEES PAID
EPA
PERMIT No. G-35
------- |