Volatile Organic Compounds (VOCs)
Volatile organic compounds (VOCs) are carbon containing chemicals that vaporize and can enter the body through normal breathing. VOCs can come from many 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.
VOCs are chemicals that have high vapor pressures and fairly low boiling points and that tend to vaporize from the liquid or solid state under normal atmospheric conditions. Vapor pressure relates to the equilibrium of a substance between its solid or liquid state and its gas state, that is, the rate at which a liquid evaporates or a solid sublimates. If the vapor pressure is high, then the substance will move to the gas phase more quickly. Substances with high vapor pressure at room temperature are said to be volatile. VOCs also often have low boiling points (often below room temperature) that contribute to their vaporization. Examples of some common VOCs are formaldehyde, benzene, toluene, limonene, and hexane.
Removing VOCs from the Air
Using an activated carbon (a carbon or charcoal that is very porous and has a large surface area) filter is the most reliable way to remove VOCs from the air. VOCs attach to and accumulate on the activated carbon in the process known as adsorption. These filters become exhausted or "spent" and must be frequently replaced. Otherwise, the adsorbed VOCs may desorb, or leave the surface of the activated carbon and return to the air.
CDPH's Position on VOCs
Part of the mission of the Indoor Air Quality (IAQ) Section is the reduction of exposure to indoor, airborne chemicals. In 2008, CDPH published the first health based standard for testing building materials for chemical emissions (Section 01350). Along with other agencies, CDPH has written purchasing guidelines that include IAQ criteria that mandate low chemical emissions. The department supports the California Air Resources Board's (CARB) formaldehyde regulation, which limits formaldehyde emissions from composite wood products.
CDPH Building Materials Emissions Study (2003)
In order to determine the effect of materials with recycled content in relation to indoor air quality, it became clear that emissions data were required for standard building materials and their alternative sustainable counterparts. This concern prompted the CIWMB to fund a laboratory-based, three-phase study by the Public Health Institute (PHI), with the Department of Health Services (DHS) being the principal investigator. The study focused entirely on those building materials with indoor air quality implications.
CDPH Reducing Occupant Exposure to VOCs-Guidelines (1996)
The guidelines presented in this document are the result of Chapter 1229 of the Statutes of 1990 (AB 3588, Speier - see Appendix A) that required the Indoor Air Quality Program (now Indoor Air Quality Section) of the California Department of Health Services (CDHS) to "develop nonbinding guidelines for the reduction of exposure to volatile organic compounds (VOCs) from construction materials in newly constructed or remodeled office buildings." The originating legislation was the result of concern about increasing complaints of sick building syndrome (SBS). This is a situation in which building occupants report symptoms, such as mucous membrane irritation, headaches, stuffiness, lethargy, and drowsiness, and which the occupants associate with a building. Researchers have reported that VOCs play a role in many SBS complaints, particularly in new or newly renovated office buildings, which often have substantial amounts of building and furnishing materials that emit VOCs.
CARB Remedies for Reducing Formaldehyde in Schools (2002)
Recommendations of the California Air Resources Board and Department of Health Services
When a classroom has been measured with elevated formaldehyde levels (more than 27 parts per billion--ppb), we recommend that the school implement the basic measures listed below. Classrooms with formaldehyde levels below 27 ppb would benefit from these measures as well, because formaldehyde is a carcinogen, and it is desirable to achieve the lowest formaldehyde levels reasonably feasible. However, achieving very low indoor levels (below 5-10 ppb) generally is not possible. Outdoor levels average about 3 ppb, but can range up to 20 ppb in some areas, such as near traffic.
- Reduce the total amount of formaldehyde sources in the classroom.
- Provide sufficient ventilation to the classroom.
- Testing the air
- If levels are still higher than desired
- Future purchases
CDPH Standard Practice for Testing of VOCs from Various Sources Using Small-scale Environmental Chambers (2004)
The development of California’s first building-related environmental specification started in early 2000, when the Department of General Services’ (DGS’s) Procurement Division was in the process of issuing a request for bids for a three-year, $60 million open office systems furniture contract. To address this issue, the several state agencies worked with DGS, the systems furniture industry, and private consultants to issue a benchmark environmental specification for procuring open office systems furniture. This specification was issued in December 2000, and included testing and selection criteria for indoor air quality as well as requirements for recycled contents and lighting.
CDPH VOC East End Report Volume 1 (2006)
In 1999, the State Legislature directed the Department of General Services (DGS) to incorporate sustainable practices in the design and construction of 1.5 million ft2 of the Capitol Area East End Complex (CAEEC). To address the Legislature’s directive, a multi-agency team, known as the Green Team, was formed under the leadership of the Secretary of the State and Consumer Services Agency and, in partnership with the Department of Health Services, California Integrated Waste Management Board, California Energy Commission, California Air Resources Board, and Department of Water Resources worked with DGS to develop sustainable criteria for the CAEEC. These criteria, among others, included several to ensure good indoor air quality, including setting target limits on chemical emissions from interior finishing building materials and conducting airborne contaminant testing after completion of the construction and prior to occupancy. Two design/build teams were selected: one for Building 225 and another for the remaining four buildings (171, 172, 173, 174). The design/build teams were responsible for the design of the buildings (the basic shell design had been done previously by the State) and the construction.
CDPH VOC East End Report Volume 2 (2006)
Volume 2 of the report contains detailed data and graphs for all sampled locations.
CDPH Standard Method for the Testing and Evaluation of VOC Emissions from Indoor Sources Using Environmental Chambers Version 1.1 (2010)
It has been five years since the Indoor Air Quality Program issued the Standard Practice for the Testing of Volatile Organic Emissions from Various Sources Using Small-Scale Environmental Chambers (Standard Practice) on behalf of the California Sustainable Building Task Force. We recognized from the start that maintenance of this document would be required to keep up with changes in the field and to track current health standards. Limitations in staff resources have delayed this effort till now. It is our intention that the update of the Standard Practice will be a continuous process, and this document presents an initial effort.
Material Emission Testing: Certification Programs and Testing Labs