What are Volatile Organic Compounds in the Home?
Volatile organic compounds (VOCs) are the reason indoor air is more polluted than outdoor air. VOCs in the home usually number in the thousands many of which can cause adverse health effects. Volatile organic compounds or VOCs are emitted as gases from certain solids or liquids. Most people are aware of volatile organic compounds in the home also known as VOCs as volatile gases emitted from certain cleaning liquids and solvents such as paint thinner, acetone or nail polish remover, most of these omit a strong chemical smell when being used. Most adults are aware these fumes are harmful when breathed so we try to limit our exposure.
Volatile Organic Compounds (VOCs) are a large group of carbon-based chemicals that easily evaporate at room temperature. While most people can smell high levels of some VOCs, other VOCs have no odor. Odor does not indicate the level of risk from inhalation of this group of chemicals.
Because they are commonly used, some VOCs are almost always found in indoor air. The New York State Department of Health (DOH) and other agencies have studied typical levels of VOCs that may be present in indoor and outdoor air. Sometimes these levels are called “background levels”. health.ny.gov
Pollution 2 to 5 Times Higher Indoors Than Outdoors
It is usually the more unknown, continuous and long term sources of volatile organic compounds in the home that cause the most long term health symptoms. It’s the VOC out-gassing of materials such as building products, floor coverings and furnishings etc. that are usually associated with what has come to be known as “Sick House Syndrome”. The VOC laden materials the house was built and furnished with are constantly in the home and continue to emit volatile organic compounds in the home for many years. Usually emitting at a much higher level when new and then over time; over many years the out-gassing gradually reduces to a nearly negligible level.
This is a little known fact, that the indoor air of a home in the country, far from the city, will typically have a higher pollution level that the outdoor air of a heavily industrialized city. It is the volatile organic compounds in the home that are the primary reason for this. According to EPA’s 1985 Research “Total Exposure Assessment Methodology (TEAM) Study” they 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. Concentrations of many VOCs are consistently higher where they become trapped indoors (up to ten times higher) than outdoors where they can disperse into the wide open sky.
Volatile Organic Compounds in the Home and Sick House Syndrome
As a certified indoor air quality professional, I receive several calls a year form people looking for answers about what it is inside there home that could be causing their health problems. Usually after testing and diagnosis from their doctor telling them it is most likely environmental. Most people, especially for Moms with kids and the elderly the place where they spend the great majority of their time is in the home. And it very often those volatile organic compounds in the home that is usually the source of the problem. In some cases sick house syndrome might be related more to mold than VOCs in cases of water leaks or moisture damage.
New homes and buildings especially, contribute to the highest level of VOC off-gassing in an indoor environment because of the abundant new materials generating VOC particles at the same time in such a short time period. In addition to new buildings, we also use many consumer products that emit VOC compounds, therefore the total concentration of VOC levels is much greater within the indoor environment.
VOC concentration in an indoor environment during winter is three to four times higher than the VOC concentrations during the summer. High indoor VOC levels are attributed to the low rates of air exchange between the indoor and outdoor environment as a result of tight-shut windows and the increasing use of humidifiers. WIKI
Where do VOCs come from?
There are thousands of different VOCs produced and used in our daily lives. Some common examples include:
- Ethylene glycol
- Methylene chloride
- Carpets and adhesives
- Carpet pads
- Composite wood products, particle board furniture and cabinets
- OSB sheathing, used wall sheathing and roof sheathing and sub floors
- Sealing caulks
- Upholstery fabrics
- Vinyl Floors
- Laminate Floors
Home Furnishing Products
- Foam mattresses and mattress toppers
- Synthetic upholstered fabrics
- Foam cushion furniture
- Foam pillows
- Plastic Toys
Home and Personal Care Products
- Air fresheners
- Air cleaners that produce ozone
- Cleaning and disinfecting chemicals
- Fuel oil, gasoline
- Moth balls
- Vehicle exhaust running a car in an attached garage
Behavior Factors and Causes
- How much time is spent in the home
- Individual proximity to VOC sources
- Dry cleaning clothes
- Moth balls and flakes
- Air fresheners
- Kerosene and oil fueled space heaters
- Stored gas, thinners, paints and chemicals
- Wood burning stoves
Some Indoor VOC Concentrations Factors
- How new the product is
- Type of VOCs present
- Amount of VOCs in a product;
- Rate at which the VOCs are released;
- Volume of the air in the room/building;
- Fresh air ventilation rate
- Concentration level of VOCs in “fresh air supply”