VOC Questions
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1 - What Are the Sources of VOCs in Indoor Environments?

VOCs may come from many different sources.  They are used as ingredients in paints, cleaning products, and adhesives.  They are released by building materials such as carpet, linoleum, composite wood products, and insulation to name a few.  Office equipment such as printers, copiers, and fax machines may also emit VOCs.  In new or recently renovated buildings, construction materials and furniture will off-gas (release) VOCs, while in older buildings, maintenance activities such as cleaning and remodeling can release VOCs.  Formaldehyde is emitted from numerous indoor sources, including building materials, composite wood furnishings, personal care products, cosmetics, permanent-pressed clothing, combustion sources, and adhesives.  Additionally, building occupants may be sources of VOCs through use of personal care products such as antiperspirants and cologne.  Environmental tobacco smoke, also known as secondhand smoke, is another source of indoor VOCs.  VOCs may be also formed from reactions between ozone, ultraviolet radiation, and terpenes (a large class of carbon compounds produced by many plants, especially conifers) and other VOCs.

Although the total quantity of VOCs emitted indoors is less than the quantity emitted outdoors, indoor concentrations and thus exposures are often greater than outdoors.  There are several reasons for this; VOCs that are released in the outdoor environment can disperse fairly rapidly, while those released within a building are confined by the building envelope and are mainly diluted by the building's ventilation system.  US Environmental Protection Agency's Total Exposure Assessment Methodology (TEAM) studies found levels of common organic pollutants to be 2 to 5 times greater inside homes than outside, regardless of whether the homes were located in rural or highly industrial areas.  

2 - What Are the Health Effects of VOCs?

Many chemicals in the indoor environment can have serious health effects.  Symptoms of VOC exposure can include eye, nose, and throad irritation, headache, nausea, fatigue, and dizziness.  Chemicals such as formaldehyde and chlorinated solvents are common in indoor air and may exacerbate asthma and cause irritant effects.  Although many indoor air chemicals can cause irritation, repeated exposure may lead to long-term health effects.

3 - What's That New Building Smell?

Many carpets, resilient floorings, cabinetry, paints, adhesives, and furniture used in modern buildings will release VOCs when newly installed.  Many newly built or recently remodeled or painted buildings have more VOCs than older structures.  Increased ventilation can decrease VOC concentration and thus exposure.  The amount of VOCs emitted by new furnishings will decrease with time and ventilation.  Pre-airing of carpets or furnishings can decrease VOC emissions after installation.  Although most paint sold in California is now either Low- or No-VOCs, there will still be a new paint smell.  By its very nature, paint will release a much higher amount of VOCs after application.  The chemicals emitted by paint will decrease as the paint cures.

  • Open windows and use fans to move air through the room to decrease exposure during and after painting.
  • Occupants of new or renovated buildings should consider delaying occupancy after construction to allow for additional airing.

4 - Are There VOCs in Green Cleaning Agents?

Many cleaning products and room deodorizers, even those claimed to be "Green," contain VOCs.  These chemicals include terpenes such as pinene and limonene.  Terpenes will react with chemicals such as ozone to form many other chemicals including formaldehyde.

  • Increase ventilation (for example, open windows or turn on exhaust fans) during and after using products that contain VOCs.

5 - Do Air Cleaners Remove VOCs?

Certain types of air cleaners will remove VOCs if used correctly.  There are many varieties of air cleaners on the market.  To remove VOCs, it is necessary to adsorb (accumulate) them onto a surface, such as activated carbon (a carbon or charcoal that has been processed to make it very porous and have a large surface area available for adsorption).  Although relatively small amounts of activated carbon can remove odors from rooms, many chemicals have health effects even if you cannot smell them.  Adsorption is a process in which the amount of gathered VOCs reaches equilibrium (a state of balance resulting in no overall change), so the process may not remove all VOCs in one pass.  All adsorbents have limited capacities and need to be frequently replaced.  Adsorbent-based air cleaners, if not properly maintained, may even release adsorbed VOCs back into the environment. 

  • Air cleaners that produce ozone should be avoided as ozone will react with many VOCs and semi-volatile organic compounds (SVOCs) to form ultrafine particles and small molecular weight VOCs.

6 - Should I Test for VOCs in My Home or Office?

Testing should not be done.  Reliable sampling for VOCs is costly and requires expertise and equipment that is not available to the general public.  As a single VOC may have many sources within a room, testing, in most cases, will not provide much useful information.  As a matter of fact, every object in a room will emit many chemicals, so it is extremely difficult to determine the source of a particular chemical in the air.  In most cases, the rate at which VOCs are emitted from building materials will decrease with time.  Increased ventilation will also decrease exposure to VOCs.

7 - How Is Testing Done for VOCs?

Building Material Testing
The California Standard Practice for Testing of VOCs from Various Sources Using Small Chambers (updated 2010 Version 1.1) was developed to put into effect emission limits based on health data.  The test uses the State of California's Office of Environmental Health and Hazard Assessment Chronic Reference Exposure Limit list for limits.  Using the results from this test, building designers can specify low VOC-emitting materials for building projects. Click here for more information.

More information about the test – The test features a 10-day conditioning period during a 14-day test with standardized conditions in small environmental chambers to simulate aging.  Air passing over the specimens is sampled for a wide range of VOCs and aldehydes at specified timed intervals.  Samples are analyzed using Thermal Desorption-Gas Chromatography/Mass Spectrometry and High Performance Liquid Chromatography with the resulting emissions modeled for a standard office and classroom.

Office Furniture Systems

CDPH has worked with other stakeholders to create purchasing specifications for office furnishings that include Indoor Air Quality Specifications.  These specifications have been created in collaboration with the California Department of General Services (CDGS), the California Air Resources Board (CARB), the California Integrated Waste Management Board (CIWMB), and the Business Institutional Furnishings Manufacturers Association (BIFMA).  The test requires that office furniture systems meet health-based emission limits.  Click here for more information.