What You Should Know About
Combustion
Appliances
and Indoor
Air
Pollution
Prepared by
.AMERICAN
.LUNG
ASSOCIATION
The Christmas Seal Peopleฎ
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What You Should
Know About
Combustion
Appliances and
Indoor Air Pollution
Hazards may be associated with almost all types of
appliances. The purpose of this booklet is to answer
some common questions you may have about the
potential for one specific type of hazard - indoor
air pollution - associated with one class of
appliances - combustion appliances.
Combustion appliances are those which burn
fuels for warmth, cooking, or decorative purposes.
Typical fuels are gas, both natural and liquefied
petroleum (LP); kerosene; oil; coal; and wood.
Examples of the appliances are space heaters,
ranges, ovens, stoves, furnaces, fireplaces, water
heaters, and clothes dryers. These appliances are
usually safe. However, under certain conditions,
these appliances can produce combustion
pollutants that can damage your health, or even
kill you.
POSSIBLE HEALTH EFFECTS range from
headaches, dizziness, sleepiness, and watery
eyes to breathing difficulties or even death.
Similar effects may also occur because of
common medical problems or other indoor air
pollutants.
This booklet was written: (1) to encourage the
proper use, maintenance, and installation of com-
bustion appliances; (2) to discuss the pollutants pro-
duced by these appliances; (3) to describe how
these pollutants can affect your health; and (4) to
tell you how you can reduce your exposure
to them.
This booklet has been prepared by the
U.S. Consumer Product Safety Commission,
the U.S. Environmental Protection Agency,
and the American Lung Associationฎ
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Should I be concerned
about indoor air pollution?
Yes. Studies have shown that the air in our homes
can be even more polluted than the outdoor air in
big cities. Because people spend a lot of time in-
doors, the quality of the air indoors can affect their
health. Infants, young children and the elderly are
a group shown to be more susceptible to pollutants.
People with chronic respiratory or cardiovascular
illness or immune system diseases are also more
susceptible than others to pollutants.
Many factors determine whether pollutants in
your home will affect your health. They include the
presence, use, and condition of pollutant sources,!
the level of pollutants both indoors and out, the
amount of ventilation in your home, and your
overall health. ;
Most homes have more than one source of indoor
air pollution. For example, pollutants come from
tobacco smoke, building materials, decorating pro-
ducts, home furnishings, and activities such as
cooking, heating, cooling, and cleaning. Living in
areas with high outdoor levels of pollutants usually
results in high indoor levels. Combustion pollutants
are one category of indoor air pollutants.
What are combustion
pollutants?
Combustion pollutants are gases or particles that
come from burning materials. The combustion
pollutants discussed in this booklet come from
burning fuels in appliances. The common fuels
burned in these appliances are natural or LP gas,
fuel oil, kerosene, wood, or coal. The types and
amounts of pollutants produced depend upon the
type of applicance, how well the appliance is
installed, maintained, and vented, and the kind of
fuel it uses. Some of the common pollutants pro-
duced from burning these fuels are carbon monox-
ide, nitrogen dioxide, particles, and sulfur dioxide.
Particles can have hazardous chemicals attached
to them. Other pollutants that can be produced by
some appliances are unburned hydrocarbons
and aldehydes.
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Combustion always produces water vapor. Water
vapor is not usually considered a pollutant, but it
can act as one. It can result in high humidity and
wet surfaces. These conditions encourage the
growth of biological pollutants such as house dust
mites, molds, and bacteria.
Where do combustion
pollutants come from?
Combustion pollutants found indoors include: out-
door air, tobacco smoke, exhaust from car and
lawn mower internal combustion engines, and
some hobby activities such as welding, wood-
burning, and soldering. Combustion pollutants can
also come from vented or unvented combustion
appliances. These appliances include space heaters,
gas ranges and ovens, furnaces, gas water heaters,
gas clothes dryers, wood or coal-burning stoves,
and fireplaces. As a group these are called "com-
bustion appliances."
What is a vented
appliance? What is an
unvented appliance?
Vented appliances are appliances designed to be
used with a duct, chimney, pipe, or other device
that carry the combustion pollutants outside the
home. These appliances can release large amounts
of pollutants directly into your home, if a vent is
not properly installed, or is blocked or leaking.
Unvented appliances do not vent to the outside,
so they release combustion pollutants directly into
the home.
Look at the box below for typical appliance pro-
blems that cause the release of pollutants in your
home. Many of these problems are hard for a
homeowner to identify. A professional is needed.
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COMBUSTION APPLIANCES
AND POTENTIAL PROBLEMS
Appliances
Fuel
Typical Potential Problems
Central Furnaces Natural or
Room Heaters Liquified
Gas Fireplaces Petroleum
Gas
Cracked heat exchanger
Not enough air to burn
fuel properly
Defective/blocked flue
Maladjusted burner
Central Furnaces Oil
Cracked heat exchanger
Not enough air to burn
fuel properly
Defective/blocked flue
Maladjusted burner
Central Heaters Wood Cracked heat exchanger
Room Heaters Not enough air to burn
fuel properly
Defective/blocked flue i
Green or treated wood
Central Furnaces Coal Cracked heat exchanger
Stoves Not enough air to burn
fuel properly
Defective/blocked flue
Defective grate
Room Heaters Kerosene Improper adjustment
Central Heaters Wrong fuel (not K-l)
Wrong wick or wick height
Not enough air to burn
fuel properly !
Water Heaters
Ranges
Ovens
Stoves
Fireplaces
Natural or
Liquefied
Petroleum
Gas
Natural or
Liquefied
Petroleum
Gas
Wood
Coal
Not enough air to bum
fuel properly
Defective/blocked flue
Maladjusted burner
Not enough air to burn
fuel properly
Maladjusted burner
Misuse as a room heater
Not enough air to burn
fuel properly
Defecth^locked flue
Green or treated wood
Cracked heat exchanger
or firebox
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Can I use charcoal grills or
charcoal hibachis indoors?
No. Never use these appliances inside homes,
trailers, truck-caps, or tents. Carbon monoxide
from burning and smoldering charcoal can kill you
if you use it indoors for cooking or heating. There
are about 25 deaths each year from the use of char-
coal grills and hibachis indoors.
NEVER burn charcoal inside homes, trailers,
tents, or other enclosures. The carbon monox-
ide can kill you.
What are the health
effects of combustion
pollutants?
The health effects of combustion pollutants range
from headaches and breathing difficulties to death.
The health effects may show up immediately after
exposure or occur after being exposed to the
pollutants for a long time. The effects depend upon
the type and amount of pollutants and the length
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of time of exposure to them. They also depend
upon several factors related to the exposed person.
These include the age and any- existing health pro-
blems. There are still some questions about the
level of pollutants or the period of exposure needed
to produce specific health effects. Further studies
to better define the release of pollutants from com-1
bustion appliances and their health effects
are needed.
The sections below discuss health problems
associated with some common combustion
pollutants. These pollutants include carbon monox-
ide, nitrogen dioxide, particles, and sulfur dioxide.
Even if you are healthy, high levels of carbon
monoxide can kill you within a short time. The
health effects of the other pollutants are generally
more subtle and are more likely to affect suscep-
tible people. It is always a good idea to reduce
exposure to combustion pollutants by using and
maintaining combustion appliances properly.
Carbon Monoxide:
Each year, according to CPSC, there are more than
200 carbon monoxide deaths related to the use of
all types of combustion appliances in the home. Ex-
posure to carbon monoxide reduces the blood's
ability to carry oxygen. Often a person or an en-
tire family may not recognize that carbon monox-
ide is poisoning them. The chemical is odorless and
some of the symptoms are similar to common
illnesses. This is particularly dangerous because
carbon monoxide's deadly effects will not
be recognized until it is too late to take action
against them.
Carbon monoxide exposures especially affect un-
born babies, infants, and people with anemia or a
history of heart disease. Breathing low levels of the
chemical can cause fatigue and increase chest pain
in people with chronic heart disease. Breathing
higher levels of carbon monoxide causes symptoms
such as headaches, dizziness, and weakness in
healthy people. Carbon monoxide also causes
sleepiness, nausea, vomiting, confusion, and
disorientation. At very high levels it causes loss of
consciousness and death.
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Nitrogen Dioxide:
Breathing high levels of nitrogen dioxide causes ir-
ritation of the respiratory tract and causes shortness
of breath. Compared to healthy .people, children,
and individuals with respiratory illnesses such as
asthma, may be more susceptible to the effects of
nitrogen dioxide.
Some studies have shown that children may have
more colds and flu when exposed to low levels of
nitrogen dioxide. When people with asthma inhale
low levels of nitrogen dioxide while exercising,
their lung airways can narrow and react more to
inhaled materials.
Particles:
Particles suspended in the air can cause eye, nose,
throat, and lung irritation. They can increase
respiratory symptoms, especially in people with
chronic lung disease or heart problems. Certain
chemicals attached to particles may cause lung
cancer, if they are inhaled. The risk of lung cancer
increases with the amount and length of exposure.
The health effects from inhaling particles depend
upon many factors, including the size of the parti-
cle and its chemical make-up.
Sulfur Dioxide:
Sulfur dioxide at low levels of exposure can cause
eye, nose, and respiratory tract irritation. At high
exposure levels, it causes the lung airways to
narrow. This causes wheezing, chest tightness, or
breathing problems. People with asthma are par-
ticularly susceptible to the effects of sulfur diox-
ide. They may have symptoms at levels that are
much lower than the rest of the population.
Other Pollutants:
Combustion may release other pollutants. They in-
clude unburned hydrocarbons and aldehydes. Lit-
tle is known about the levels of these pollutants
in indoor air and the resulting health effects.
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What do I do if I suspect
that combustion pollutants
are affecting my health?
If you suspect you are being subjected to
carbon monoxide poisoning get fresh aiir
immediately. Open windows and doors for more
ventilation, turn off any combustion appliances,
and leave the house. You could lose consciousness
and die from carbon monoxide poisoning if you do
nothing. It is also important to contact a doctor
IMMEDIATELY for a proper diagnosis. Remember
to tell your doctor that you suspect carbon monox-
ide poisoning is causing your problems. Prompt
medical attention is important.
Remember that some symptoms from combustion
pollutants - headaches, dizziness, sleepiness,
coughing, and watery eyes - may also occur
because of common medical problems. These
medical problems include colds, the flu, or allergies.
Similar symptoms may also occur because of other
indoor air pollutants. Contact your doctor for a pro-
per diagnosis.
To help your doctor make the correct diagnosis,
try to have answers to the following questions:
Do your symptoms occur only in the home? Do
they disappear or decrease when you leave
home, and reappear when you return?
Is anyone else in your household complaining of
similar symptoms, such as headaches, dizziness,,
or sleepiness? Are they complaining of nausea,
watery eyes, coughing, or nose and throat
irritation?
Do you always have symptoms?
Are your symptoms getting worse?
Do you often catch colds or get the flu?
Are you using any combustion appliances in
your home?
Has anyone inspected your appliances lately? Are
you certain they are working properly?
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Your doctor may take a blood sample to measure
the level of carbon monoxide in your blood if he
or she suspects carbon monoxide poisoning. This
sample will help determine whether carbon monox-
ide is affecting your health.
Contact qualified appliance service people to
have your appliances inspected and adjusted if
needed. You should be able to find a qualified per-
son by asking your appliance distributor or your
fuel supplier. In some areas, the local fuel company
may be able to inspect and adjust the appliance.
How can I reduce my
exposure to combustion
pollutants?
Proper selection, installation, inspection and
maintenance of your appliances are extremely
important in reducing your exposure to these
pollutants. Providing good ventilation in your home
and correctly using your appliance can also reduce
your exposure to these pollutants.
Additionally, there are several different residen-
tial carbon monoxide detectors for sale. The CPSC
is encouraging the development of detectors that
will provide maximum protection. These detectors
would warn consumers of harmful carbon monox-
ide levels in the home. They may soon be widely
available to reduce deaths from carbon monoxide
poisoning.
APPLIANCE SELECTION
Choose vented appliances whenever possible.
Only buy combustion appliances that have
been tested and certified to meet current
safety standards. Examples of certifying
organizations are Underwriters Laboratories (UL)
and the American Gas Association (AGA)
Laboratories. Look for a label that clearly shows
the certification.
All currently manufactured vented gas heaters
are required by industry safety standards to
have a safety shut-off device. This device helps
protect you from carbon monoxide poisoning by
shutting off an improperly vented heater.
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Check your local and state building codes and
fire ordinances to see if you can use am
unvented space heater, if you consider pur--
chasing one. They are not allowed to be used
in some communities, dwellings, or certain rooms
in the house. :
If you must replace an unvented gas space
heater with another, make it a new one,,
Heaters made after 1982 have a pilot light safety
system called an oxygen depletion sensor (ODS).
This system shuts off the heater when there is
not enough fresh air, before the heater begins
producing large amounts of carbon monoxide.
Look for the label that tells you that the
appliance has this safety system. Older heaters
will not have this protection system.
Consider buying gas appliances that have
electronic ignitions rather than pilot lights,,
These appliances are usually more energy effi-
cient and eliminate the continuous low-level
pollutants from pilot lights.
Buy appliances that are the correct size for
the area you want to heat. Using the wrong size:
heater may produce more pollutants in your
home and is not an efficient use of energy.
Talk to your dealer to determine the type anct
size of appliance you will need. You may wish
to write to the appliance manufacturer or asso-
ciation for more information on the appliance.
Some addresses are in the back of this booklet!
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All new woodstoves are EPA-certified to limit
the amounts of pollutants released into the
outdoor air. For more information on selecting,
installing, operating, and maintaining wood-
burning stoves, write to the EPA Wood Heater
Program. Their address is in the back of this
booklet. Before buying a woodstove check your
local laws about the installation and use of
woodstoves.
Proper Installation
You should have your appliances profes-
sionally installed. Professionals should follow
the installation directions and applicable building
codes. Improperly installed appliances can release
dangerous pollutants in your home and may
create a fire hazard. Be sure that the installer
checks for backdrafting on all vented appliances.
A qualified installer knows how to do this.
Ventilation
To reduce indoor air pollution, a good supply
of fresh outdoor air is needed. The movement
of air into and out of your home is very impor-
tant. Normally, air comes through cracks around
doors and windows. This air helps reduce the
level of pollutants indoors. This supply of fresh
air is also important to help carry pollutants up
the chimney, stovepipe, or flue to the outside.
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Keep doors open to the rest of the house from
the room where you are using an unvented
gas space heater or kerosene heater, and
crack open a window. This allows enough air
for proper combustion and reduces the level of
pollutants, especially carbon monoxide.
Use a hood fan, if you are using a range. They
reduce the level of pollutants you breath, if they
exhaust to the outside. Make sure that enough
air is coming into the house when you use an
exhaust fan. If needed, slightly open a door or
window, especially if other appliances are in use.
For proper operation of most combustion
appliances and their venting system, the air
pressure in the house should be greater than that
outside. If not, the vented appliances could
release combustion pollutants into the house
rather than outdoors. If you suspect that you
have this problem you may need the help of a
qualified person to solve it. ;
Make sure that your vented appliance has the
vent connected and that nothing is blocking
it. Make sure there are no holes or cracks in the
vent. Do not vent gas clothes dryers or water1
heaters into the house for heating. This is
unsafe. i
Open the stove's damper when adding wood.
This allows more air into the stove. More air helps
the wood burn properly and prevents pollutants
from being drawn back into the house instead of
going up the chimney. Visible smoke or a.
constant smoky odor inside the home when using
a woodburning stove is a sign that the stove is
not working properly. Soot on furniture in the
rooms where you are using the stove also tells
this. Smoke and soot are signs that the stove is
releasing pollutants into the indoor air.
Correct Use
Read and follow the instructions for all
appliances so you understand how they
work. Keep the owner's manual in a convenient
place to refer to when needed. Also, read and
follow the warning labels because they tell you
important safety information that you need to
know. Reading and following the instructions and
warning labels could save your life.
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INSTRUCTIONS
CAUTION: Risk of indoor
air pollution. Use this
heater only in a well
ventilated area. See
operating instructions for
CAUTION: Improper fuel may cause
pollution and sooting of the burner.
Use only water clear No. 1-K kerosene.
DANGER: Risk of explosion. Never use
gasoline in this heater.
Always use the correct fuel for the
appliance.
Only use water-clear ASTM 1-K kerosene
for kerosene heaters. The use of kerosene
other than 1-K could lead to a release of more
pollutants in your home. Never use gasoline in
a kerosene heater because it can cause a fire
or an explosion. Using even small amounts of
gasoline could cause a fire.
Use seasoned hardwoods (elm, maple, oak)
instead of softwoods (cedar, fir, pine) in
woodburning stoves and fireplaces. Hard-
woods are better because they burn hotter and
form less creosote, an oily, black tar that sticks
to chimneys and stove pipes. Do not use green
or wet woods as the primary wood because
they make more creosote and smoke. Never
burn painted scrap wood or wood treated with
preservatives, because they could release
highly toxic pollutants, such as arsenic or lead.
Plastics, charcoal, and colored paper such as
comics, also produce pollutants. Never burn
anything that the stove or fireplace manufac-
turer does not recommend.
' Never use a range, oven, or dryer to heat
your home. When you misuse gas appliances in
this way, they can produce fatal amounts of car-
bon monoxide. They can produce high levels of
nitrogen dioxide, too.
ป Never use an unvented combustion heater
overnight or in a room where you are sleep-
ing. Carbon monoxide from combustion heaters
can reach dangerous levels.
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Never ignore a safety device when it shuts
off an appliance. It means that something is
wrong. Read your appliance instructions to find
out what you should do or have a professional
check out the problem. !
Never ignore the smell of fuel. This usually
indicates that the appliance is not operating
properly or is leaking fuel. Leaking fuel will not,
always be detectible by smell. If you suspect that,
you have a fuel leak have it fixed as soon as
possible. In most cases you should shut off the
appliance, extinguish any other flames or pilot,
lights, shut off other appliances in the area, open
windows and doors, call for help, and leave
the area.
Inspection and Maintenance
Have your combustion appliance regularly
inspected and maintained to reduce your
exposure to pollutants. Appliances that are not
working properly can release harmful and even
fatal amounts of pollutants, especially carbon
monoxide. i
Have chimneys and vents inspected when
installing or changing vented heating ap-
pliances. Some modifications may be required.
For example, if a change was made in your
heating system from oil to natural gas, the flue
gas produced by the gas system could be hot
enough to melt accumulated oil combustion
debris in the chimney or vent. This debris could
block the vent forcing pollutants into the house.
It is important to clean your chimney and vents
especially when changing heating systems.
!
i
What are the inspection
and maintenance
procedures?
The best advice is to follow the recommendations
of the manufacturer. The same combustion ap-
pliance may have different inspection and
maintenance requirements, depending upon where
you live.
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In general, check the flame in the furnace com-
bustion chamber at the beginning of the heating
season. Natural gas furnaces should have a blue
flame with perhaps only a slight yellow tip. Call
your appliance service representative to adjust the
burner if there is a lot of yellow in the flame, or
call your local utility company for this service. LP
units should have a flame with a bright blue center
that may have a light yellow tip. Pilot lights on gas
water heaters and gas cooking appliances should
also have a blue flame. Have a trained service
representative adjust the pilot light if it is yellow
or orange.
Before each heating season, have flues and
chimneys inspected and cleaned before each
heating season for leakage and for blockage by
creosote or debris. Creosote buildup or leakage
could cause black stains on the outside of the
chimney or flue. These stains can mean that
pollutants are leaking into the house.
The chart on the next page shows how and when
to take care of your appliance.
This booklet discussed the types of pollutants that
may be produced by combustion appliances,
described how they might affect your health, and
suggested ways you could reduce your exposure to
them. It also explained that proper appliance selec-
tion, installation, operation, inspection, and
maintenance are very important in reducing ex-
posure to combustion pollutants.
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INSPECTION AND
MAINTENANCE SCHEDULES
Applicance
Gas Hot Air
Heating System
Gas/Oil
Water/Steam
Heating Systems
and Water
Heaters
Kerosene
Space Heaters
Wood/Coal
Stoves
Inspection/
Frequency
Air Filters -
Monthly
Look at flues
for rust and
soot - Yearly
Look at flues
for rust and
soot - Yearly
Look to see
that mantle is
properly seated -
Daily when
in use
Look to see
that fuel tank
is free of water
or other
contaminants -
Daily or before
refueling
Look at flues
for rust and
soot - Yearly
Maintenance/
Frequency
Clean/change filter -
As needed
Qualified person check/
clean chimney, clean
combustion chamber,
adjust burners, check
heat exchanger
and operation
Yearly (at start of
heating season)
Qualified person check/
clean chimney, clean
combustion chamber,
adjust burners,
check operation
Yearly (at start of
heating season)
Check and replace wick
Yearly (at start of
heating season)
Clean combustion
chamber
Yearly (at start of
heating season)
Drain fuel tank
Yearly (at end of
heating season)
Qualified person
check/clean chimney,
check seams
and gaskets,
check operation
Yearly (at start of
heating season)
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For more information:
For a copy of CPSC's booklets What You Should
Know About Space Heaters and What You Should
Know About Kerosene Heaters, and for information
on asbestos, biological pollutants, lead, methylene
chloride, humidifiers, and formaldehyde in your
home, write to:
U.S. Consumer Product Safety Commission
Washington, D.C. 20207
For a copy of The Inside Story: A Guide to Indoor
Air Quality, and additional information on indoor
air quality write:
Public Information Center (PM-211B)
U.S. Environmental Protection Agency
401 M Street, SW
Washington, D.C. 20460
Information on indoor air quality is also available
from local American Lung Association (ALA)
offices. They are listed in the white pages of the
phone book.
For information on woodstoves write:
Wood Heater Program (EN-341W)
U.S. Environmental Protection Agency
401 M Street, SW
Washington, DC 20460
For information on kerosene heaters, write or call:
National Kerosene Heater Association
3100 West End Avenue, Suite 250
Nashville, TN 37203
(Telephone: 615-269-9015)
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For information on gas heating appliances, write:
Gas Appliance Manufacturers Association, Inc.
1901 North Moore Street, Suite 1100
Arlington, VA 22209
American Gas Association
1515 Wilson Blvd.
Arlington, VA 22209
For a copy of Straight Answers to Burning Ques-
tions or other woodburning information, write:
Wood Heating Alliance
1101 Connecticut Ave N.W., Suite 700
Washington, DC 20036
Note: The CPSC and the EPA have not reviewed or approved
all the information and documents on indoor air quality that
may be provided by other groups or organizations.
This document may be reproduced without change, in whole
or in part, without permission, except for use as advertising
material or product endorsement. Any such reproduction
should credit the American Lung Association, the U.S. Con-
sumer Product Safety Commission, and the U.S. Environmental
Protection Agency. The use of all or any part of this document
in a deceptive manner or for purposes of endorsing a particular
product may be subject to appropriate legal action.
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U.S. Consumer Product Safety Commission
Washington, D.C. 20207
U.S. Environmental Protection Agency
Washington, D.C. 20460
t
AMERICAN & LUNG ASSOCIATION0
The Christmas Seal People
Contact your local American Lung Association
for more information.
009109
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