beaker of water


A volatile organic compound (VOC) has a molecular make-up containing carbon and chemical properties that allow it to be present as a gas under typical room temperature. The term VOC applies to a very broad category of chemicals, and they can be found in many forms in the environment, including both human-made and naturally occurring chemical compounds. VOCs are most often referred to in the context of chemicals that have the potential to affect the environment or human health. Consequently, VOCs are defined in different ways under different environmental, health and safety regulations.
VOCs are present throughout our environment. They are used in many industrial processes in the creation of consumer products. Two examples are tetrachloroethylene, a solvent used in numerous industrial processes and metal cleaning practices, and benzene, which is also a solvent and is found in gasoline, other petroleum products and various alcohols. VOCs are also essential ingredients in many personal care products and other materials including fragrances, paints, lubricants, adhesives, cleaners, gasoline additives, home furnishings and more.

The primary route of exposure to VOCs is through inhalation, but it also possible to ingest them in food and water. For some VOCs, exposure through the skin is also a consideration. When released, VOCs move easily through the environment. They can seep into the soil and eventually end up in groundwater. VOCs are not usually found in drinking water that comes from surface water sources such as lakes, reservoirs or streams, because they tend to evaporate into the air.
It is possible for individual VOCs to reach levels of concern in drinking water. There are currently 23 compounds regulated as VOCs in drinking water. Of these, eight are described as human carcinogens, or probable or possible carcinogens.

The potential for VOCs to be a health concern depends on the toxicity of the actual contaminant, the concentration of the contaminant, the exposure conditions and the duration or exposure. Factors like age, health condition, gender and exposure to other chemicals can impact potential health effects for individuals.

Employees who work in environments in which they are exposed to large amounts of particular VOCs in the air have been found to suffer negative health effects. If ingested above certain levels, various VOCs have been found to cause cancer, problems in the liver, kidneys and nervous system, and skin and reproductive issues.
Your community water provider tests for 23 regulated VOCs, and many systems recently tested for an additional seven VOCs as part of the Third Unregulated Contaminant Monitoring Rule.

Your system publishes its test results in its consumer confidence report each year. The report is often available on the internet, and you may also contact your water provider to request a printed copy. Contact your public water system to learn more about VOC testing and results. You can usually find contact information for your public water system on your water bill.
EPA has established drinking water standards for 23 VOC compounds, and water utilities are required to monitor for these compounds. When routine monitoring indicates that individual VOC contaminant levels are above the maximum contaminant level set by EPA (or a more stringent standard set by individual states), the water system must take steps to reduce the amount of contaminant present. Your utility is also required to alert its customers if levels exceed the MCL.

Seven VOCs that are not currently regulated are being monitored under EPA’s Third Unregulated Contaminant Monitoring Rule. These seven VOCs are: trichloropropane, 1,3-butadiene, chloromethane (methyl chloride), dichloroethane, bromomethane (methyl bromide), chlorodifluoromethane (HCFC-22) and bromochloromethane (halon 1011). EPA will examine both potential health risks and occurrence data when determining if these VOCs should be regulated.
EPA announced in February 2011 that it was evaluating whether or not to propose a new regulation for a group of VOCs that it believes are potential carcinogens. The agency has identified a list of eight compounds that are not currently regulated for consideration in this rulemaking: aniline, benzyl chloride, 1,3-butadiene, 1,1-dichloroethane, nitrobenzene, methyl-oxirane, 1,2,3-trichloropropane and urethane. Water systems recently collected data on three of these VOCs under the Third Unregulated Contaminant Monitoring Rule.

If the UCMR3 testing shows that a large number of U.S. drinking water systems have detected some or all of the seven VOCs at amounts of concern, EPA may decide to regulate some or all of them in the future.
If you get your drinking water from a private well, you should have your water tested by a certified laboratory regularly. You can find information on how to sample for VOCs and where to send samples for analysis by contacting your state water laboratory certification officer. Contact information for your state can be found on EPA's drinking water lab certification page. Additional information about well water testing from EPA is available on their private drinking water well FAQ page.
If you are concerned about VOCs in your drinking water, you may consider purchasing a home treatment device. However, in order to make a well-informed and cost-effective decision, consider:
  • Checking with your utility or consumer confidence report to learn about the amount of various VOCs in your water and
  • Identifying a device that has been independently certified to remove those VOCs.
NSF International, the Water Quality Association, Underwriters Laboratories and CSA International all certify home treatment products for removal of contaminants. The relevant VOC removal standard is NSF/ANSI Standard 53, and various drinking water treatment technologies are effective at removing VOCs. If you choose to use a home treatment device, it is very important to follow the manufacturer's operation and maintenance instructions carefully in order to make sure the device works properly.
Bottled water quality can vary. Bottled water in the United States is regulated by the U.S. Food and Drug Administration and is required to meet standards equal to the EPA’s tap water standards. There are also individual state standards. However, in most cases, you must contact the bottled water manufacturer for information about contaminant levels.