What are VOCs?
VOCs or volatile organic compounds are carbon-containing chemicals that evaporate readily at room temperature. They consist of various types of molecules and exist primarily in a gaseous state. VOCs may also be adsorbed onto airborne particulates or indoor surfaces. These compounds are found in both indoor and outdoor air. Some of the more common VOCs in a household include benzene (paint), formaldehyde (carpets) and toluene (glue).
Where do VOCs come from?
VOC emissions occur from both natural and manmade sources. Isoprenes and monoterpenes are produced by trees to repel insects and attract pollinators. Manmade emissions may result from the vaporization of chemical compounds directly into the atmosphere or incomplete combustion of fossil fuels.
Outdoor sources include automobile exhaust, industrial processes, and wood burning. Indoors, VOCs may be released into the air by household or office products including personal care items, glue, air fresheners and printers. VOCs are also frequently produced from the off-gassing of building materials such as wood, carpet, and paint. The level of VOCs found indoors can vary significantly depending on the activities of the occupants and their use of products that emits VOCs. However, studies have found that the level of VOCs averages 2 to 5 times higher indoors than outdoors.
If you want to learn more about other indoor air quality pollutants and where they come from, click here.
Why are VOCs harmful?
The health effects of VOCs can vary depending on the compound, concentration, and duration of exposure. Symptoms of exposure may include irritation of the eyes, nose, and throat, as well as nausea and difficulty breathing. Additionally, VOCs have been linked to chronic health conditions such as asthma, liver damage and central nervous system damage. Some are known or suspected carcinogens. For example, formaldehyde, a chemical commonly used to pressure treat wood, was established as a carcinogen by the World Health Organization in 1996 based on data from occupational exposure. In 2009, further evidence was presented to support claims that it causes leukemia as well.
A wide variety of industrial and residential products contain VOCs including paints, fuels, cosmetics and refrigerants. If spilled or not disposed of properly, they can seep into the soil and contaminate groundwater. Additionally, in the presence of sunlight, VOCs will undergo a reaction with nitrogen oxides to produce ground-level ozone. This can contribute to smog and other air quality concerns.
The majority of studies performed on the adverse health effects of VOCs have focused on occupational exposure. However, blood analyses of 600 non-occupationally exposed participants in the Third National Health and Nutrition Examination Survey found that many participants had detectable concentrations of at least 11 VOCs. Moreover, studies performed by researchers at Berkeley National Laboratory revealed that among 300 reports of building-related health issues in schools, many had inadequate ventilation – thus compounding the problem further.
In other instances where VOC levels were investigated, a correlation was found between exposure to VOCs and reports of asthma, sick building syndrome and respiratory ailments. The levels of VOCs in schools are also a concern since children are more susceptible to VOC’s adverse effects than adults. David O. Carpenter, M.D., of the Institute for Health and the Environment at the University at Albany stated, “The brain is a major target for VOCs, causing everything from a headache and loss of concentration to learning disabilities in children…”
What is being done to reduce VOC levels?
Given many negative VOC effects are occurring in public spaces where you may have little control over, what are some steps being taken by the regulatory agencies to address VOC concerns?
The US Environmental Protection Agency (EPA) has implemented several strategies to reduce VOC emissions. The Clean Air Act was first introduced in 1970 and is revised periodically to address risks. In 1998, the EPA set forth regulations limiting VOC emissions from consumer products such as hair spray, foam cups, and house paints.
This requires manufacturers, importers, and distributors to limit the amount of VOCs in their products. Performance standards for storage tanks used in the production of crude oil and natural gas were proposed in 2012. A citizen’s’ petition requesting regulation of formaldehyde in composite wood products led to the passage of the Formaldehyde Standards for Composite Wood Products Act in 2008. The EPA tracks VOC emissions through the National Emissions Inventory, a composite of data from various sources including industry and state and local organizations. Data for VOC emissions from various man-made sources from 1990 through 2011 are shown below.
How to reduce exposure to indoor VOCs
You can reduce the level of VOCs in your home by limiting the use of products that will emit high levels of VOCs. In certain instances, you can choose from products with low or zero-VOC labelings (paints and sealants now have low and VOC-free alternatives).
When using products that produce VOCs, make sure you have proper ventilation in the room by opening all windows and doors to introduce better airflow and outdoor air. Exercising good practical applications and storing of products with VOCs will also help reduce introducing VOCs into your home. In fact, you should only buy the number of products you need and avoid unnecessarily storing chemical products in closed-off space such as your storage closet and garage.
For unavoidable products where low-VOC versions may not be cost effective (such as carpets and furnishing), you can air them outside before placing them into your home. Lastly, pay close attention to directions and warning labels for chemical products in your home. For reference, the U.S. Department of Health & Human Services keeps a helpful household products database where you can learn more about the chemicals in common household items and precautions that should be taken when using them.
