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Indoor Air Quality (IAQ)

Addressing Indoor Environmental Concerns During Remodeling

Overview

While remodeling or improving the energy efficiency of your home, steps should be taken to minimize pollution from sources inside the home, either from new materials, or from disturbing materials already in the home. In addition, residents should be alert to signs of inadequate ventilation, such as stuffy air, moisture condensation on cold surfaces, or mold and mildew growth. These issues should be addressed either before or during the remodeling process.

Usually the most effective way to improve indoor air quality is to eliminate or control sources of pollution, or to reduce their emissions. Another important approach that goes hand in hand with controlling pollution is using mechanical ventilation to lower the concentrations of pollutants in your home by increasing the amount of outdoor air coming inside. A third strategy, air cleaning, complements source control and ventilation.

Radon

Test your homes for radon. Radon is the second leading cause of lung cancer in the U.S. You can't see or smell radon, but it's not hard to measure the level of radon in your home. Testing is easy and should only take a little of your time. For more information, see:

EPA recommends fixing your home if a test shows radon levels in your home exceed the action level of 4 picocuries per liter of air (pCi/L). If you are building an addition (or a new home!) there are radon-resistant new construction techniques you can use to help prevent high radon levels.

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Lead

Lead has long been recognized as a harmful environmental pollutant. Lead is particularly dangerous to children because their growing bodies absorb more lead than adults do and their brains and nervous systems are more sensitive to the damaging effects of lead. Babies and young children can also be more highly exposed to lead because they often put their hands and other objects that can have lead from dust or soil on them into their mouths. Children may also be exposed to lead by eating and drinking food or water containing lead or from dishes or glasses that contain lead, inhaling lead dust from lead-based paint or lead-contaminated soil or from playing with toys with lead paint. Before it was known how harmful lead could be, it was used in paint, gasoline, water pipes, and many other products.

Old lead-based paint is the most significant source of lead exposure in the U.S. today. Harmful exposures to lead can be created when lead-based paint is improperly removed from surfaces by dry scraping, sanding, or open-flame burning. High concentrations of airborne lead particles in homes can also result from lead dust from outdoor sources, including contaminated soil tracked inside, and use of lead in certain indoor activities such as soldering and stained-glass making.

To learn more about lead, how to protect your family, or find information for contractors, visit EPA's Lead page.

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Asbestos

Asbestos is the name of a group of naturally-occurring minerals that separate into strong, very fine fibers. The fibers are heat-resistant and extremely durable; and, because of these qualities, asbestos became useful in construction and industry. In the home it may or may not pose a health hazard to the occupants, depending on its condition. When it can be crushed by hand pressure or the surface is not sealed, to prevent small pieces from escaping, the material is considered FRIABLE. In this condition fibers can be released and pose a health risk, such as lung cancer from inhaling the fibers. However, as long as the surface is stable, not damaged and well-sealed against the release of its fibers and not damaged, the material is considered safe until damaged in some way.

To learn more about asbestos, including how to identify it and how to protect those in your home during a remodeling project, read EPA's Asbestos in the Home: A Homeowner's Guide (EPA 910-K-92-001, 1990). This booklet responds to frequently asked questions about asbestos and provides information to help the homeowner make informed decisions about its care and maintenance.

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Moisture Control

Too much moisture in a home can lead to mold, mildew and other biological growth. This in turn can lead to a variety of health effects ranging from more common allergic reactions, to asthma attacks and hypersensitivity pneumonitits, for example.

Excess moisture can be in the form of high relative humidity including humidity generated by people and their activities such as:

  • showers
  • cooking
  • drying clothes

Water can also come from:

  • plumbing leaks
  • wet boots
  • splashing around sinks

Moisture can travel with infiltrating outdoor air (or exfiltrating indoor air) through the building shell, including the foundation. In addition to health problems, high relative humidity or water that enters building cavities that is not allowed to dry quickly can lead to problems such as rot, structural damage and premature paint failure.

Methods to control moisture include building an energy-efficient home with proper air-sealing, proper use of vapor barriers and vapor diffusion strategies. The entire building envelope, from the foundation to the roof, should be designed to not only prevent moisture entry, but also to allow any moisture which does enter a means to escape. As mentioned above, people and their activities in a home are big sources of moisture; thus proper ventilation is also important in order to maintain indoor humidity levels within an acceptable range.

Moisture Control Techniques

  1. Manage water outside the foundation walls.

    The ground around the home's foundation should be graded to slope down and away from the house at a rate of 1/2" to 1" per linear foot to drain surface water away from the house. Water from down spouts should be directed away from the house, discharging at least a few feet from the foundation. Test any underground drains with a hose to make sure they are working properly. Drains that are not working should be repaired or replaced with an elbow discharge described above. Be sure that driveways, sidewalks and patios slope down and away from foundation walls at 1/4" per linear foot.

    In extreme cases, you may have to dig out around the foundation and replace the fill with an exterior drain tile and with a good draining material such a clean gravel. Because this can be very expensive in existing homes, you should get a few opinions as to whether this is necessary. In some areas, there may not be enough room outside the dwelling to provide proper drainage - in these cases, it is often recommended that interior drain tile and a sump pump be installed to remove water from basements and crawlspaces. This also can be very expensive.
  2. Manage water inside the foundation walls and in the basement or crawl space floor.

    If the basement or crawl space has a dirt floor, cover it with 6 mil poly, overlapping edges by at least 12 inches. Seal any cracks or joints in the foundation wall or slab with an elastomeric caulk.
  3. Use construction techniques to control water, air movement, vapor diffusion and condensation. Use construction methods and materials which promote the drying of building assemblies.

    Use construction techniques which reduce the likelihood that warm, moist air will come in contact with cold surfaces, leading to condensation, mold growth and rot. This includes controlling air movement and using vapor barriers on the warm side of walls and roofs. Proper flashing and drainage techniques should be used to keep rainwater out. There are different strategies to achieve this, and the strategies vary widely depending on the climate. For a good discussion of the approaches, consult a building manual such as the Energy Efficient Building Association's (EEBA) Builder's Guide for your climate.
  4. Roofs.

    It is important that the roof and flashing details and construction effectively keep water out of the house. It is also important that the roof and attic design addresses the issue of moisture in the form of water vapor to avoid condensation in building cavities. There is no single strategy which will work for all houses in all climate conditions. The important considerations are preventing movement of moisture from the warm side to the cold side of the building envelope, and managing moisture which does pass through the envelope to prevent condensation on building materials.
  5. Ensure the home is properly ventilated, with at least exhaust fans in the bathroom and kitchen and preferably a mechanical ventilation system designed to ventilate the entire house.
    High relative humidity (RH) can lead to problems with mold, dust mites and other biological pollutants. Using exhaust fans in the bathrooms and kitchen can remove much of the moisture that builds up from everyday activities and help to keep RH below 50%. 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 also exhaust odors and pollutants from these rooms. These fans can be part of an active ventilation system for the entire house, and help to reduce humidity levels. Vent bathroom, kitchen and clothes dryer/laundry room exhausts directly to the outside, not into an attic or other enclosed space.
  6. Size Air-Conditioning Equipment correctly.

    More is not always better. Incorrectly sized equipment can lead to operational and cost problems. Oversized air conditioning systems can "short-cycle" leading to rapid cooling without reducing indoor humidity levels. This can lead to a variety of problems associated with high relative humidity. Heat gain and heat loss should be determined for each house. The Air Conditioning Contractors of America (ACCA) provides a recognized standard procedure in the publication, Manual J®. Equipment should be sized for each individual house because even identically built homes will be affected by variations such as solar orientation and shading which affect heating and cooling loads.
    Correct refrigerant charge (not under- or over-charged) and proper maintenance are also necessary for optimum performance of air conditioners.
  7. Low Relative Humidity.

    Below 30 percent relative humidity, people can be uncomfortable and can suffer from dry mucus membranes which can lead to nosebleeds and infections. In general, low relative humidity is only a problem during the winter months, when the outside air contains very little moisture. It is this dry outside air entering the home through cracks and openings in the building shell that causes the inside air to become dry. The greater the amount of outside air which leaks into the house, the dryer the indoor air becomes. By air-sealing and using energy-efficient construction, uncontrolled air leakage is greatly reduced, a more controlled indoor environment is created, and moisture can be maintained at acceptable levels without the use of a humidifier. Humidifiers require maintenance to avoid becoming breeding grounds for biological contaminants.

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Ventilation

If too little outdoor air enters a home, pollutants can sometimes accumulate to levels that can pose health and comfort problems. Likewise, one approach to lowering the concentrations of indoor air pollutants in your home is to increase the amount of outdoor air coming in.

Outdoor air enters and leaves a house by:

  • infiltration
  • natural ventilation
  • mechanical ventilation

In a process known as infiltration, outdoor air flows into the house through:

  • openings
  • joints
  • cracks in:
    • walls
    • floors
    • ceilings
  • around windows and doors (air may also move out of the house in this manner — this is called exfiltration)

In natural ventilation, air moves through opened windows and doors. Air movement associated with infiltration and natural ventilation is caused by air temperature differences between indoors and outdoors and by wind. Finally, there are a number of mechanical ventilation devices, from exhaust (vented outdoors) fans that intermittently remove air from a single room, such as bathrooms and the kitchen, to air handling systems that use fans and duct work to continuously remove indoor air and distribute filtered and conditioned outdoor air to strategic points throughout the house. The rate at which outdoor air replaces indoor air is described as the air exchange rate. When there is little infiltration, natural ventilation or mechanical ventilation, the air exchange rate is low and pollutant levels can increase.

Unless they are built with means of mechanical ventilation, homes that are designed and constructed to minimize the amount of outdoor air that can "leak" into and out of the home may have higher pollutant levels than other homes. However, because some weather conditions can drastically reduce the amount of outdoor air that enters a home, pollutants can build up even in homes that are normally considered "leaky."

Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house. Opening windows and doors, operating window or attic fans, when the weather permits, or running a window air-conditioner with the vent control open increases the ventilation rate. Local bathroom or kitchen fans that exhaust outdoors remove contaminants, including moisture, directly from the room where the fan is located and also increase the outdoor air ventilation rate.

Ideally, new homes will be built to minimize leakage to control energy loss, improve comfort and minimize the transport of moisture and pollutants through the building shell. These homes should then also have mechanical ventilation to remove pollutants generated in the home and provide outdoor air in a controlled manner. Whether a mechanical ventilation system makes sense in your existing homes depends on the house, your existing heating, ventilation and air-conditioning (HVAC) system, and the changes you have planned. You should discuss this with your HVAC contractor. A local Weatherization office, or building performance contractor, might also be able to help you with this decision or point you to local experts.

How much ventilation do I need?

The American Society of Heating, Refrigeration and Air-Conditioning Engineering, or ASHRAE provides procedures for determining whole-house ventilation rates in its Standard 62.2, "Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings". The standard also provides requirements for exhaust ventilation for kitchens, bathrooms and other point sources, such as clothes dryers and venting for fuel-burning appliances.

For a basic overview of ventilation, including different types ventilation systems, try the following resources:

For a detailed analysis of ventilation system options for new homes, see the Lawrence Berkeley National Laboratory report Recommended Ventilation Strategies for Energy-Efficient Production Homes (PDF)(49 pp, 404 K, About PDF).

Copies of ASHRAE Standard 62 are available from ASHRAE.

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Preventing Problems with Combustion Equipment

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
  • wood

Examples include:

  • space heaters
  • ranges
  • furnaces
  • fireplaces
  • water heaters
  • clothes dryers

These appliances are usually safe. However, under certain conditions (see below), these appliances can release harmful or deadly combustion pollutants into the home (commonly called combustion spillage or backdrafting). In addition, unvented or improperly vented appliances can add large amounts of moisture to the air, potentially resulting in both biological growth and damage to the house. Proper selection, installation, inspection and maintenance of combustion appliances are extremely important. Providing good ventilation can also can reduce exposure to combustion pollutants.

Things to consider when remodeling your home are listed below. For a more complete discussion of combustion appliances, see the following:

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Read equipment's home owner manual and instructions. Make sure equipment receives regular professional inspection and maintenance.

It is important that you understand how to properly operate combustion equipment in your homes, and that you follow the manufacturer's recommendations for maintaining the equipment. Have your combustion appliances--and your chimney--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, into the living space.

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Avoid installing unvented (or "vent-free") space or water heating appliances.

Unvented appliances leave all combustion products in the house. Even if incomplete combustion pollutants such as carbon monoxide (CO) are kept to a minimum, these enerate large amounts of moisture which can create its own problems. Unvented heaters require special precautions.

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When replacing heating equipment, consider using only sealed-combustion, induced draft, or power-vented furnaces, boilers and water heaters.

Traditionally, combustion equipment relied on natural draft, the tendency for the warm combustion air to rise up a chimney. Today's more efficient equipment does not waste as much energy or send as much heat up the chimney, weakening natural draft. Natural draft can at times be overcome by conditions that depressurize the house, leading to spillage, backdrafting and the problems associated with combustion products in the house.

ENERGY STAR equipment usually features sealed combustion or power-venting. The risk of backdrafting is lower with these types of equipment than for those relying on natural draft.

Sealed combustion equipment draws its combustion air directly from outside the home. The combustion products are exhausted directly out of the home. The air intakes and exhaust are sealed off from the inside of the home, and this greatly reduces the chance for any spillage of combustion products into the home.

While induced draft and power-vented appliances rely on air in the home for combustion, they use a fan to force pollutants out of the home. This reduces the chance of natural draft being overcome by other fans or pressures in the home.

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Use a properly sized range hood fan if you use a gas range.

All kitchens should have exhaust ventilation to remove odors and excess moisture associated with cooking. While there are various ventilation strategies for kitchens, a range hood is the most common. When using a gas range, a range hood directly vented to the outside should be used to capture the combustion products. These range hoods should be sized correctly. For a typical kitchen range the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) and the Home Ventilation Institute (HVI) recommend 100 cfm. Larger fans may need to have makeup air provided to avoid excessively depressurizing the house, causing backdrafting or other problems.

After installation of combustion and/or ventilation equipment, combustion equipment should be tested to be sure that it functions properly.

It is important that your installer conducts a worst-case depressurization test. This combustion safety test determines if any non-sealed combustion appliances will backdraft or spill combustion products into the living space. Tell your installer this test should use an established procedure such as Appendix D of the International Fuel and Gas Code or ASTM E1998 "Guide for Assessing Backdrafting and Spillage from Vented Combustion Appliances"

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Vent clothes dryers to the outside.

Always vent clothes dryers directly outside. In addition to combustion products produced by gas dryers, all dryers generate large amounts of moisture and particulates which should be vented out of the house before they have the opportunity to create problems.

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Consider installing a Carbon Monoxide alarm.

Carbon monoxide (CO) is a colorless, odorless gas which at high levels can cause serious illness and death. CO alarms are widely available and should be considered a back-up to BUT NOT A REPLACEMENT for proper installation, use and maintenance of fuel-burning appliances. CO alarms are designed to warn you of any unusual build-up of CO in your home. These higher levels of CO may occur from improperly maintained, installed or used fuel-burning appliances, backdrafting appliances or fireplaces, or idling cars in garages. If a CO alarm is to be installed:

  1. Make sure the device is certified to the most current Underwriters Laboratory (UL) standard 2034 or the International Approval Services (IAS) 6-96 standard.
  2. Install a CO alarm in the hallway near every separate sleeping area.
  3. Be aware of all instructions and warnings associated with the CO alarm.

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Air Ducts

Ducts should be tightly sealed to reduce air leakage. This is achieved by carefully sealing all duct seams and joints. (Note that standard cloth duct tape is not a suitable duct sealant material.) This can save energy and prevent contaminants from entering ductwork and circulating through the home. Air-sealing of ductwork also helps to balance the pressure of airflow through the ducts, preventing unplanned negative or positive pressures in the house that can lead to other problems. For example, leaky return ducts can create negative pressures which may lead to radon problems or combustion equipment backdrafting (see information on radon and combustion safety). Remodeling may present an opportunity to seal ducts that would otherwise be difficult to access.

During the actual renovation work, air duct registers in the area being renovated should be sealed during activities that will generate a lot of dust or debris. This can be done by taping plastic over the registers. Before the project is started, you should decide on a ventilation strategy to remove pollutants from the work area and prevent them from moving to other areas of the home (see good work practices for more information).

Some people consider cleaning air ducts either as part of a renovation, or because they may be "dirty". Knowledge about air duct cleaning is in its early stages, so a blanket recommendation cannot be offered as to whether you should have the air ducts in your home cleaned. EPA urges you to read Should You Have the Air Ducts In Your Home Cleaned if you are thinking about having your air ducts cleaned.

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Integrated Pest Management

[note: The IAQ Tools for Schools Action Kit outlines how to implement an Integrated Pest Management program in the IAQ Reference Guide - Appendix K - Integrated Pest Management.]

Houses and apartments are often hosts to common pests such as:

  • cockroaches
  • fleas
  • termites
  • ants
  • mice
  • rats

Pests can be a health hazard to you, your family and your pets. It’s easy to understand why you may need and want to control them. Nowadays, you can choose from many different methods as you plan your strategy for controlling pests. Sometimes a non-chemical method of control is as effective and convenient as a chemical alternative. For many pests, total elimination is almost impossible, but it is possible to control them.

Knowing your options is the key to pest control. Methods available to you include:

  • pest prevention
  • non-chemical pest controls
  • chemical pesticides

The most effective strategy for controlling pests may be to combine methods in an approach known as integrated pest management (IPM) that emphasizes preventing pest damage. In IPM, information about pests and available pest control methods is used to manage pest damage by the most economical means and with the least possible hazard to people, property and the environment.

Preventing Pest Problems

Pests seek places to live that satisfy basic needs for air, moisture, food and shelter. The best way to control pests is to try to prevent them from entering your home or garden in the first place. You can do this by removing the elements that they need to survive. Remodeling and renovation offer opportunities to take the following preventive actions to prevent indoor pest problems:

  • Remove water. All living things, including pests, need water for survival. Fix leaky plumbing, and do not let water accumulate anywhere in or around your home. Remove or dry out water-damaged and wet materials. Even dampness or high humidity can attract pests.
  • Remove or block off indoor pest hiding places. Caulk cracks and crevices to control pest access. Avoid storing newspapers, paper bags and boxes for long periods of time. Also, check for pests in packages or boxes before carrying them into your home.
  • Block pest entryways. Install screens on all floor drains, windows and doors to discourage crawling and flying pests from entering your home. Make sure any passageways through the floor are blocked. Place weatherstripping on doors and windows. Caulk and seal openings in walls. Keep doors shut when not in use.
  • Remove food. Consider pest-proof food and waste containers. You may use this as a criterion when evaluating cabinetry or designing space.

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Painting

There are many factors to consider before beginning a painting project. Special care should be taken when sanding a surface to prepare for painting due to the dust released into the air. The dust may contain lead particles, if the surface contains lead-based paint. Exposure to excessive levels of lead could affect a child's mental growth, and interfere with nervous system development, which could cause learning disabilities and impaired hearing. In adults, lead can increase blood pressure. Unless a lead-based paint inspection shows it doesn't, you should treat paint in homes built before 1978 as if it contained lead.

Most paints give off volatile organic compounds (VOCs) — chemicals that evaporate in the air — that could lead to IAQ problems. The ability of these chemicals to cause health effects varies greatly. As with any chemical, the likelihood of a reaction and the extent and type of health effect will depend on many factors. These factors include:

  • the amount of chemical in the indoor air
  • the length of time a person is exposed to the chemical
  • a person's age
  • pre-existing medical conditions
  • individual susceptibility

Eye and throat or lung irritation, headaches, dizziness and vision problems are among the immediate symptoms that some people have experienced soon after exposure to some chemicals. In professional painters who are exposed to high levels of paint vapors for long periods of time, some chemicals in paints have damaged the nervous system, liver and kidneys. Some chemicals cause cancer or reproductive and developmental effects in laboratory animals. Because of these concerns, susceptible people, such as young children and individuals with breathing problems, should avoid paint vapors. To avoid any health risks for themselves and their unborn babies, pregnant women should avoid undertaking painting projects and should limit their time in freshly painted rooms, especially when oil-based paints are being used.

Recommendations

  1. Check that the painted surface is lead-free (or assume that any existing paint contains lead) before preparing a surface for repainting.
  • Determine that the existing surface is lead-free OR assume surface contains lead-based paint.
  • If paint is lead-based, use appropriate preparation and painting techniques.
  • For homes built before 1978, always hire contractors that use only lead-safe certified renovators.
  1. Select an appropriate paint.
  • Many water-based paints (even interior paints) have, until recently, used mercury as a fungicide. Any paint that contains mercury should not be used indoors. Evaluate any existing stock of paint and properly dispose of paints containing lead or mercury.
  • With painting indoors, make sure you select paints that are for indoor use. Do not use exterior paints indoors.
  • Evaluate new paint before you purchase it. There are two categories of interior paints, water-based and oil-based. Water-based paints are referred to as "latex" paints. The oil-based paints are referred to as "alkyd" paints. In general, water-based paints will emit fewer chemicals and lower levels of chemical vapors. Short-term exposure to solvents from alkyd paints can be significantly higher than from latex paints. Express your IAQ concerns to paint suppliers and use their technical personnel as a resource. Not all paint suppliers have information on pollutant emissions; consult other source (For example: manufacturers) if your paint supplier cannot provide adequate information.
  1. Always read and follow all the instructions and safety precautions on the label
  • Do not assume you already know how to use the product. The hazards may be different from one product to another. some ingredients in individual products may also change over time. The label tells you what action you should take to reduce hazards and the first aid measures to use if there is a problem.
  1. During interior painting, minimize exposing people to odors and contaminants.
  • Try to schedule interior painting when the home is unoccupied, for example: when people are at work or school, or on vacation. Under normal temperature and humidity, most emissions occur during drying, in the first few days after painting. You can also try to schedule painting for dry periods in the fall or spring, when windows are more easily left open for ventilation.
  • Use exhaust fans to remove paint fumes from the building. Exhaust fans (such as a box fan, blowing from the room to the outdoors) should be used in the area being painted to remove fumes. Supply fans can be used in adjacent areas to keep fumes out. Operate fans and provide as much ventilation as possible continuously (24 hours/day, 7 days/week) from the beginning of the painting work until 2 or 3 days after painting has been completed.
  • Block any heating or air-conditioning return openings — opening which send air back to the furnace or air-conditioner — in the rooms you are painting (if necessary turn off the regular home heating, cooling, or ventilation systems) to prevent circulating air from the work area to other areas of the home. If supply air is necessary for heating/cooling, make sure to provide adequate exhaust ventilation to avoid pressurizing the room and driving pollutants to other parts of the house. Do not block a cold air return with the furnace or air-conditioner running if it is the only return in the house.
  1. Use Appropriate Storage and Disposal Practices for Paints, Solvents and Clean-up Materials.
  • Latex paint usually cleans up with soap and water. For alkyd paints, you will need to purchase specific products as listed on the label. Never use gasoline to clean paint brushes. Gasoline is extremely flammable. Read the label to find out if the paint cleaner is flammable. All flammable products should be used away from ignition sources such as water heaters, furnaces, electric motors, fans, etc.
  • Seal containers carefully after use.
  • Buy only as much paint as you need to finish the job to avoid having to store or dispose of unused paint.
  • When possible, keep paint containers in storage areas equipped with exhaust ventilation, but not near heating, ventilation, or air-conditioning equipment rooms.
  • Use an appropriate waste disposal method to dispose of any paints containing lead or mercury.
  1. Use and handle paint strippers properly.
  • Paint strippers contain chemicals that loosen paint from surfaces. These chemicals can harm you if not used properly. Some paint stripping chemicals can irritate the skin and eyes, or cause headaches, drowsiness, nausea, dizziness, or loss of coordination. Some may cause cancer, reproductive problems, or damage of the liver, kidney, or brain. Others catch fire easily. Proper handling and use of paint strippers will reduce your exposure to these chemicals and lessen your health risk.
    • For more information see What You Should Know About Using Paint Strippers (CPSC-F-747-F-95-002).

More Information

For additional information see the publication Healthy Indoor Painting Practices (PDF) (2 pp, 117K, About PDF) by the U.S. EPA and the U.S. Consumer Product Safety Commission.

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Remodeling and Volatile Organic Compounds (VOCs)

Organic chemicals are widely used as ingredients in building materials and household products. Remodeling often involves the use of paints, varnishes, sealants and adhesives which all contain organic solvents. These are in addition to many cleaning, disinfecting, cosmetic, degreasing and hobby products used in homes. Fuels are also made up of organic chemicals. All of these products can release organic compounds while you are using them; and, to some degree, when they are stored. Studies have found levels of about a dozen common organic pollutants to be 2 to 5 times higher inside homes than outside, regardless of whether the homes were located in rural or highly industrial areas. Fortunately, steps can be taken to reduce VOCs released indoors.

Health Effects of Exposure to VOCs

The ability of organic chemicals to cause health effects varies greatly, from those that are highly toxic, to those with no known health effect. As with other pollutants, the extent and nature of the health effect will depend on many factors including level of exposure and length of time exposed. Eye and respiratory tract irritation, headaches, dizziness, visual disorders and memory impairment are among the immediate symptoms that some people have experienced soon after exposure to some organics. At present, not much is known about what health effects occur from the levels of organics usually found in homes. Many organic compounds are known to cause cancer in animals; some are suspected of causing, or are known to cause, cancer in humans.

Minimizing Impact of VOCs During Remodeling

Minimize the use of building products containing formaldehyde or other VOCs within the conditioned space of the house.

Pressed wood products, adhesives and many finishes (such as paints and varnishes) contain VOCs which may off-gas in varying amounts over time. There are several complementary strategies to minimize problems:

  • To the extent possible during remodeling, eliminate or reduce the use of these products inside the living space of the house.
  • Consider using solid wood with low-emitting finishes.
  • Consider the use of pre-finished materials or those that can be finished outside the living space.
  • When engineered products such as pressed wood are used, sealing as many surfaces as possible should help to reduce the rate of emissions. Low-emitting sealants should be used. Check with vendors of engineered wood products for recommendations on sealing their products.
  • Use "exterior-grade" pressed wood products (lower-emitting because they contain phenol-formaldehyde resins rather than urea-formaldehyde resins).
  • Wherever possible, use low-emitting products in the house's conditioned space, such as sealants, paints and finishes. Use these products according the manufacturers' directions, and provide plenty of ventilation both during and after application. Check with vendors to see if they have low-emitting products which are suitable for your specific needs and applications.
  • See the discussion of painting for strategies to use barriers and ventilation to minimize occupant exposure to pollutants during the remodeling work.

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