Biological Pollutants in the Home
Outdoor air pollution in cities is a
major health problem. Much effort and money continues to be spent cleaning up
pollution in the outdoor air. But air pollution can be a problem where you least
expect it, in the place you may have thought was safest - your home. Many
ordinary activities such as cooking, heating, cooling, cleaning, and
redecorating can cause the release and spread of indoor pollutants at home.
Studies have shown that the air in our homes can be even more polluted than
outdoor air. Many Americans spend up to 90 percent of their time indoors, often
at home. Therefore, breathing clean indoor air can have an important impact on
health. People who are inside a great deal may be at greater risk of developing
health problems, or having problems made worse by indoor air pollutants. These
people include infants, young children the elderly and those with chronic
illnesses. 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.
What Are Biological Pollutants?
Biological pollutants are or were living organisms. They promote poor
indoor air quality and may be a major cause of days lost from work or school,
and of doctor and hospital visits. Some can even damage surfaces inside and
outside your house. Biological pollutants can travel through the air and are
often invisible. Some common indoor biological pollutants are:
(minute scales from hair, feathers, or skin)
Dust Mite and Cockroach parts
Infectious agents (bacteria or viruses)
Some of these
substances are in every home. It is impossible to get rid of them all. Even a
spotless home may permit the growth of biological pollutants. Two conditions are
essential to support biological growth nutrients and moisture. These conditions
can be found in many locations, such as bathrooms, damp or flooded basements,
wet appliances (such as humidifiers or air conditioners), and even some carpets
and furniture. Modern materials and construction techniques may reduce the
amount of outside air brought into buildings which may result in high moisture
levels inside. Using humidifiers, unvented heaters, and air conditioners in our
homes has increased the chances of moisture forming on interior surfaces. This
encourages the growth of certain biological pollutants.
Of The Problem
Most information about sources and health effects of
biological pollutants is based on studies of large office buildings and surveys
of homes in northern U.S. and Canada. These surveys show that 30% to 50% of all
structures have damp conditions which may encourage the growth and buildup of
biological pollutants. This percentage is likely to be higher in warm, moist
climates. Some diseases or illnesses have been linked with biological pollutants
in the indoor environment. However, many of them also have causes unrelated to
the indoor environment. Therefore, we do not know how many health problems
relate only to poor indoor air.
Health Effects Of Biological
All of us are exposed to biological pollutants. However,
the effects on our health depend upon the type and amount of biological
pollution and the individual person. Some people do not experience health
reactions from certain biological pollutants, while others may experience one or
more of the following reactions:
for the spread of infections indoors, allergic reactions may be the most common
health problem with indoor air quality in homes. They are often connected with
animal dander (mostly from cats and dogs), with house dust mites (microscopic
animals living in household dust), and with pollen. Allergic reactions can range
from mildly uncomfortable to life-threatening, as in a severe asthma attack.
Some common signs and symptoms are:
Runny nose and sneezing
Wheezing and difficulty
Health experts are especially concerned
about people with asthma. These people have very sensitive airways that can
react to various irritants, making breathing difficult. The number of people who
have asthma has greatly increased in recent years. The number of people with
asthma has gone up by 59 percent since 1970, to a total of 9.6 million people.
Asthma in children under 15 years of age has increased 41 percent in the same
period, to a total of 2.6 million children. The number of deaths from asthma is
up by 68 percent since 1979, to a total of almost 4,400 deaths per
Talking to Your Doctor
Are you concerned about
the effects on your health that may be related to biological pollutants in your
home? Before you discuss your concerns with your doctor, you should know the
answers to the following questions. This information can help the doctor
determine whether your health problems may be related to biological
Does anyone in the family have frequent headaches, fevers, itchy
watery eyes, a stuffy nose, dry throat, or a cough? Does anyone complain of
feeling tired or dizzy all the time? Is anyone wheezing or having difficulties
breathing on a regular basis?
Did these symptoms appear after you moved to a
new or different home?
Do the symptoms disappear when you go to school or
the office or go away on a trip, and return when you come back?
recently remodeled your home or done any energy conservation work, such as
installing insulation, storm windows, or weather stripping? Did your symptoms
occur during or after these activities?
Does your home feel humid? Can you
see moisture on the windows or on other surfaces, such as walls and ceilings?
What is the usual temperature in your home? Is it very hot or cold?
you recently had water damage?
Is your basement wet or damp?
any obvious mold or mildew?
Does any part of your home have a musty or moldy
Is the air stale?
Do you have pets?
Do your house plants show
signs of mold?
Do you have air conditioners or humidifiers that have not
been properly cleaned?
Does your home have cockroaches or
Infectious diseases caused by bacteria and viruses, such as flu,
measles, chicken pox, and tuberculosis, may be spread indoors. Most infectious
diseases pass from person to person through physical contact. Crowded conditions
with poor air circulation can promote this spread. Some bacteria and viruses
thrive in buildings and circulate through indoor ventilation systems. For
example, the bacterium causing Legionnaire's disease, a serious and sometimes
lethal infection, and Pontiac Fever, a flu-like illness, have circulated in some
Toxic reactions are the least studied and
understood health problem caused by some biological air pollutants in the home.
Toxins can damage a variety of organs and tissues in the body, including the
liver, the central nervous system, the digestive tract, and the immune
Checking Your Home
There is no simple and
cheap way to sample the air in your home to determine the level of all
biological pollutants. Experts suggest that sampling for biological pollutants
is not a useful problem-solving tool. Even if you had your home tested, it is
almost impossible to know which biological pollutant(s) cause various symptoms
or health problems. The amount of most biological substances required to cause
disease is unknown and varies from one person to the next. Does this make the
problem sound hopeless? On the
contrary, you can take several simple,
practical actions to help remove sources of biological pollutants, to help get
rid of pollutants, and to prevent their return.
Walk Through Your Home
Begin by touring your household. Follow your
nose, and use your eyes. Two major factors help create conditions for biological
pollutants to grow nutrients and constant moisture with poor air
Dust and construction materials, such as wood, wallboard, and
insulation, contain nutrients that allow biological pollutants to grow. Firewood
also is a source of moisture, fungi, and bugs.
Appliances such as
humidifiers, kerosene and gas heaters, and gas stoves add moisture to the
A musty odor, moisture on hard surfaces, or even water stains, may be
Basements, attics, and
Heating and air-conditioning ducts
Humidifiers and dehumidifiers
Refrigerator drip pans
What You Can Do
About Biological Pollutants
Before you give away the family pet or
move, there are less drastic steps that can be taken to reduce potential
problems. Properly cleaning and maintaining your home can help reduce the
problem and may avoid interrupting your normal routine. People who have health
problems such as asthma, or are allergic, may need to do this and more. Discuss
this with your doctor.
Water in your
home can come from many sources. Water can enter your home by leaking or by
seeping through basement floors. Showers or even cooking can add moisture to the
air in your home. The amount of moisture that the air in your home can hold
depends on the temperature of the air. As the temperature goes down, the air is
able to hold less moisture. This is why, in cold weather, moisture condenses on
cold surfaces (for example, drops of water form on the inside of a window). This
moisture can encourage biological pollutants to grow.
many ways to control moisture in your home:
Fix leaks and seepage. If water
is entering the house from the outside, your options range from simple
landscaping to extensive excavation and waterproofing. (The ground should slope
away from the house). Water in the basement can result from the lack of gutters
or a water flow toward the house. Water leaks in pipes or around tubs and sinks
can provide a place for biological pollutants to grow.
Put a plastic cover
over dirt crawlspaces to prevent moisture from coming in from the ground. Be
sure crawlspaces are well-ventilated.
Use exhaust fans in bathrooms and
kitchens to remove moisture to the outside (not into the attic). Vent your
clothes dryer to the outside.
Turn off certain appliances (such as
humidifiers or kerosene heaters) if you notice moisture on windows and other
Use dehumidifiers and air conditioners, especially in hot, humid
climates, to reduce moisture in the air, but be sure that the appliances
themselves don't become sources of biological pollutants.
temperature of cold surfaces where moisture condenses. Use insulation or storm
windows. (A storm window installed on the inside works better than one installed
on the outside) Open doors between rooms (especially doors to closets which may
be colder than the rooms) to increase circulation. Circulation carries heat to
the cold surfaces Increase air circulation by using fans and by moving furniture
from wall corners to promote air and heat circulation. Be sure that your house
has a source of fresh air and can expel excessive moisture from the home.
Pay special attention to carpet on concrete floors. Carpet can absorb
moisture and serve as a place for biological pollutants to grow. Use area rugs
which can be taken up and washed often. In certain climates, if carpet is to be
installed over a concrete floor, it maybe necessary to use a vapor barrier
(plastic sheeting) over the concrete and cover that with sub-flooring
(insulation covered with plywood) to prevent a moisture problem.
problems and their solutions differ from one climate to another. The Northeast
is cold and wet, the Southwest is hot and dry, the South is hot and wet, and the
Western Mountain states are cold and dry. All of these regions can have moisture
problems. For example, evaporative coolers used in the Southwest can encourage
the growth of biological pollutants. In other hot regions, the use of air
conditioners which cool the air too quickly may prevent the air conditioners
from running long enough to remove excess moisture from the air. The types of
construction and weather for the different climates can lead to different
problems and solutions.
Where Biological Pollutants May Be Found in the Home
Dirty air conditioners
Dirty humidifiers and/or dehumidifiers
Bathroom without vents or windows
Kitchen without vents or windows
Dirty refrigerator drip pans
Laundry room with unvented dryer
Carpet on damp basement floor
on outside wall
Dirty heating/air conditioning system
Dogs or cats
Water damage (around windows, the roof or the basement)
Clean All Appliances That Come In Contact With Water
Have major appliances,
such as furnaces, heat pumps and central air conditioners, inspected and cleaned
regularly by a professional, especially before seasonal use. Change filters on
heating and cooling systems according to manufacturer's directions. (In general,
change filters monthly during use.) When first turning on the heating or air
conditioning at the start of the season, consider leaving your home until it
Have window or wall air-conditioning units cleaned and serviced
regularly by a professional, especially before the cooling season. Air
conditioners can help reduce the entry of allergy-causing pollen. But they may
also become a source of biological pollutants if not properly maintained. Clean
the coils and rinse the drain pans according to manufacturer's instructions, so
water cannot collect in pools.
Have furnace-attached humidifiers cleaned and
serviced regularly by a professional, especially before the heating season.
Follow manufacturer's instructions when using any type of humidifier.
Experts differ on the benefits of using humidifiers. If you do use a portable
humidifier (approximately 1 to 2 gallon tanks), be sure to empty its tank every
day and refill with distilled or demineralized water, or even fresh tap water if
the other types of water are unavailable For larger portable humidifiers, change
the water as recommended by the manufacturer. Unplug the appliance before
cleaning. Every third day, clean all surfaces coming in contact with water with
a 3% solution of hydrogen peroxide, using a brush to loosen deposits Some
manufacturers recommend using diluted household bleach for cleaning and
maintenance, generally in a solution of one-half cup bleach to one gallon water
When any household chemical, rinse well to remove all traces of chemical before
Empty dehumidifiers daily and clean often. If
possible, have the appliance drip directly into a drain. Follow manufacturer's
instructions for cleaning and maintenance. Always disconnect the appliance
Clean refrigerator drip pans regularly according to
manufacturer's instructions. If refrigerator and freezer doors don't seal
properly, moisture may build up and mold can grow. Remove any mold on door
gaskets and replace faulty gaskets.
surfaces, such as showers and kitchen counters.
Remove mold from walls,
ceilings, floors, and paneling. Do not simply cover mold with paint, stain,
varnish, or a moisture-proof sealer, as it may resurface.
shower curtains, or remove them and scrub well with a household cleaner and
rinse before rehanging them.
Controlling dust is
very important for people who are allergic to animal dander and mites. You
cannot see mites, but you can either remove their favorite breeding grounds or
keep these areas dry and clean. Dust mites can thrive in sofas, stuffed chairs,
carpets, and bedding. Open shelves, fabric wallpaper, knickknacks, and venetian
blinds are also sources of dust mites. Dust mites live deep in the carpet and
are not removed by vacuuming. Many doctors suggest that their mite-allergic
patients use washable area rugs rather than wall-to-wall carpet.
bedding in hot water (at least 130 F) to kill dust mites. Cold water won't do
the job. Launder bedding at least every 7 to 10 days.
Use synthetic or foam
rubber mattress pads and pillows, and plastic mattress covers if you are
allergic. Do not use fuzzy wool blankets, feather or wool-stuffed comforters,
and feather pillows.
Clean rooms and closets well, dust and vacuum often to
remove surface dust. Vacuuming and other cleaning may not remove all animal
dander, dust mite material, and other biological pollutants. Some particles are
so small they can pass through vacuum bags and remain in the air. If you are
allergic to dust, wear a mask when vacuuming or dusting. People who are highly
allergy-prone should not perform these tasks. They may even need to leave the
house when someone else is cleaning.
Before You Move
yourself by inspecting your potential new home. If you identify problems, have
the landlord or seller correct them before you move in, or even consider moving
Have professionals check the heating and cooling system, including
humidifiers and vents. Have duct lining and insulation checked for growth.
Check for exhaust fans in bathrooms and kitchens. If there are no vents, do
the kitchen and bathrooms have at least one window a piece? Does the cook top
have a hood vented outside? Does the clothes dryer vent outside? Are all vents
to the outside of the building, not in attics or crawlspaces?
obvious mold growth throughout the house, including attics, basements, and
crawlspaces and around the foundation. See if there are many plants close to the
house, particularly if they are damp and rotting. They are a potential source of
biological pollutants. Downspouts from roof gutters should route water away from
Look for stains on the walls, floor or carpet (including any
carpet over concrete floors) as evidence of previous flooding or moisture
problems. Is there moisture on windows and surfaces? Are there signs of leaks or
seepage in the basement?
Look for rotted building materials which may
suggest moisture or water damage.
If you or anyone else in the family has a
pet allergy, ask if any pets have lived in the home.
Examine the design of
the building. Remember that in cold climates, overhanging areas, rooms over
unheated garages, and closets on outside walls may be prone to problems with
Look for signs of cockroaches. (Carefully read
instructions for use and any cautionary labeling on cleaning products before
beginning cleaning procedures.)
Do not mix any chemical products.
Especially, never mix cleaners containing bleach with any product (such as
ammonia) which does not have instructions for such mixing When chemicals are
combined, a dangerous gas can sometimes be formed.
Household chemicals may
cause burning or irritation to skin and eyes.
Household chemicals may be
harmful if swallowed, or inhaled.
Avoid contact with skin, eyes, mucous
membranes and clothing.
Avoid breathing vapor. Open all windows and doors
and use an exhaust fan that sends the air outside.
Keep household chemicals
out of reach of children.
Rinse treated surface areas well to remove all
traces of chemicals.
Correcting Water Damage
What if damage is already done? Follow
these guidelines for correcting water damage:
Throw out mattresses, wicker
furniture, straw baskets and the like that have been water damaged or contain
mold. These cannot be recovered.
Discard any water-damaged furnishings such
as carpets, drapes, stuffed toys, upholstered furniture and ceiling tales,
unless they can be recovered by steam cleaning or hot water washing and thorough
Remove and replace wet insulation to prevent conditions where
biological pollutants can grow.
Reducing Exposure to Biological
General good housekeeping, and maintenance of heating
and air conditioning equipment, are very important. Adequate ventilation and
good air distribution also help. The key to mold control is moisture control. If
mold is a problem, clean up the mold and get rid of excess water or moisture.
Maintaining the relative humidity between 30% - 60% will help control mold, dust
mites, and cockroaches. Employ integrated pest management to control insect and
animal allergens. Cooling tower treatment procedures exist to reduce levels of
Legionella and other organisms.
Install and use exhaust fans that
are vented to the outdoors in kitchens and bathrooms and vent clothes dryers
outdoors. These actions can eliminate much of the moisture that builds up from
everyday activities. There are exhaust fans on the market that produce little
noise, an important consideration for some people. Another benefit to using
kitchen and bathroom exhaust fans is that they can reduce levels of organic
pollutants that vaporize from hot water used in showers and dishwashers.
Ventilate the attic and crawl spaces to prevent moisture build-up. Keeping
humidity levels in these areas below 50 percent can prevent water condensation
on building materials.
If using cool mist or ultrasonic
humidifiers, clean appliances according to manufacturer's instructions and
refill with fresh water daily. Because these humidifiers can become breeding
grounds for biological contaminants, they have the potential for causing
diseases such as hypersensitivity pneumonitis and humidifier fever. Evaporation
trays in air conditioners, dehumidifiers, and refrigerators should also be
Thoroughly clean and dry water-damaged carpets
and building materials (within 24 hours if possible) or consider removal and
replacement. Water-damaged carpets and building materials can harbor mold and
bacteria. It is very difficult to completely rid such materials of biological
Keep the house clean. House dust mites, pollens,
animal dander, and other allergy-causing agents can be reduced, although not
eliminated, through regular cleaning. People who are allergic to these
pollutants should use allergen-proof mattress encasements, wash bedding in hot
(130° F) water, and avoid room furnishings that accumulate dust, especially if
they cannot be washed in hot water. Allergic individuals should also leave the
house while it is being vacuumed because vacuuming can actually increase
airborne levels of mite allergens and other biological contaminants. Using
central vacuum systems that are vented to the outdoors or vacuums with high
efficiency filters may also be of help.
Take steps to minimize
biological pollutants in basements. Clean and disinfect the basement floor drain
regularly. Do not finish a basement below ground level unless all water leaks
are patched and outdoor ventilation and adequate heat to prevent condensation
are provided. Operate a dehumidifier in the basement if needed to keep relative
humidity levels between 30 - 50 percent.
Health Effects From Biological Contaminants
contaminants trigger allergic reactions, including hypersensitivity pneumonitis,
allergic rhinitis, and some types of asthma. Infectious illnesses, such as
influenza, measles, and chicken pox are transmitted through the air. Molds and
mildews release disease-causing toxins. Symptoms of health problems caused by
biological pollutants include sneezing, watery eyes, coughing, shortness of
breath, dizziness, lethargy, fever, and digestive
Allergic reactions occur only after repeated exposure to
a specific biological allergen. However, that reaction may occur immediately
upon re-exposure or after multiple exposures over time. As a result, people who
have noticed only mild allergic reactions, or no reactions at all, may suddenly
find themselves very sensitive to particular allergens. Some diseases, like
humidifier fever, are associated with exposure to toxins from microorganisms
that can grow in large building ventilation systems. However, these diseases can
also be traced to microorganisms that grow in home heating and cooling systems
and humidifiers. Children, elderly people, and people with breathing problems,
allergies, and lung diseases are particularly susceptible to disease-causing
biological agents in the indoor air. Mold, dust mites, pet dander, and pest
droppings or body parts can trigger asthma. Biological contaminants, including
molds and pollens can cause allergic reactions for a significant portion of the
population. Tuberculosis, measles, staphylococcus infections, Legionella and
influenza are known to be transmitted by air.
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.
What are Combustion
Combustion pollutants are gases or particles that come
from burning materials. The combustion pollutants come from burning fuels in
appliances. The types and amounts of pollutants produced depend upon the type of
appliance, how well the appliance is installed, maintained, and vented, and the
kind of fuel it uses. Some of the common pollutants produced from burning these
fuels are carbon monoxide, 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.
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
Where do Combustion Pollutants Come From?
pollutants found indoors include outdoor air, tobacco smoke, exhaust from car
and lawn mower internal combustion engines, and some hobby activities such as
welding, woodburning, 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
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
problems that cause the release of pollutants in your home. Many of these
problems are hard for a homeowner to identify. A professional is needed.
What are the Health Effects of Combustion Pollutants?
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 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 problems. 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 combustion appliances and their health effects are
The sections below discuss health problems associated with some
common combustion pollutants. These pollutants include carbon monoxide, 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
susceptible people. It is always a good idea to reduce exposure to combustion
pollutants by using and maintaining combustion appliances
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. Exposure to carbon monoxide reduces the
blood's ability to carry oxygen. Often a person or an entire family may not
recognize that carbon monoxide 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 unborn 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.
Breathing high levels
of nitrogen dioxide causes irritation 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.
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 particle and its chemical
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 particularly
susceptible to the effects of sulfur dioxide. They may have symptoms at levels
that are much lower than the rest of the population.
Combustion may release other pollutants. They include unburned
hydrocarbons and aldehydes. Little is known about the levels of these pollutants
in indoor air and the resulting health effects.
What do I do if I
suspect that combustion pollutants are affecting my health?
suspect you are being subjected to carbon monoxide poisoning get fresh air
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 monoxide poisoning is causing your problems.
Prompt medical attention is important. 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 proper diagnosis.
How can I reduce my exposure to combustion
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 residential carbon monoxide detectors for sale.
These detectors would warn consumers of harmful carbon monoxide levels in the
home. They may soon be widely available to reduce deaths from carbon monoxide
Choose vented appliances whenever
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.
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.
your local and state building codes and fire ordinances to see if you can use an
unvented space heater, if you consider purchasing one. They are not allowed to
be used in some communities, dwellings, or certain rooms in the house.
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.
gas appliances that have electronic ignitions rather than pilot lights. These
appliances are usually more energy efficient 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.
All new wood
stoves 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. Before
buying a wood stove check your local laws about the installation and use of wood
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 important. 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
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
water heaters into the house for heating. This is unsafe.
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 wood burning 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 of Appliances
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.
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 wood burning stoves and fireplaces.
Hardwoods 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 manufacturer 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 carbon monoxide. They can produce high
levels of nitrogen dioxide, too.
Never use an unvented combustion heater
overnight or in a room where you are sleeping. Carbon monoxide from combustion
heaters can reach dangerous levels.
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
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.
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. Have chimneys and vents inspected when installing or
changing vented heating appliances. 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.
What are the
Inspection and Maintenance Procedures?
The best advice is to follow
the recommendations of the manufacturer. The same combustion appliance may have
different inspection and maintenance requirements, depending upon where you
live. In general, check the flame in the furnace combustion 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.