Volatile Organic Compounds (VOC)
Standard Method for Testing and Evaluation of Volatile Organic Chemical Emissions from Indoors Sources using Environmental Chambers Version 1.2 (January, 2017) (PDF)
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About 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. Examples of some common VOCs are formaldehyde, benzene, toluene, limonene, and hexane.
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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.
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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 2004, 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.
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CDPH's Publications on VOCs over the years
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.
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 after the above measures have been taken, then additional actions may be necessary, such as sealing all exposed surfaces of particleboard furnishings and/or extensive airing out of the building. For new purchases, use of low or no formaldehyde-emitting materials can be specified.
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.
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. The specification developed for open office systems furniture was used as the basis for developing an environmental specification for screening building materials by the design-build teams of a 1.5 million ft2, five-office building complex in Sacramento known as the Capitol Area East End Complex (CAEEC). This specification was entitled Special Environmental Requirements, Specifications Section 01350.
In 2004, CDPH expanded several sub-sections of the indoor air quality part of Section 01350 through the development of a "Standard Practice." This document superseded "previous versions of small-scale environmental chamber testing portion of California Specification 01350."
This study was conducted by the Indoor Air Quality Program of California Department of Health Services with the goal of expanding scientific investigation data for pre- and post-occupancy IAQ components. This study and accompanying data outlined the role of IAQ and its relationship to the sustainable construction practices implemented at the Capitol Area East End Complex (CAEEC).
The report consists of two volumes. Volume 1 contains the study description, results, lessons learned, supporting tables and figures.
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) (PDF)
In 2010, the CDPH Indoor Air Quality Program organized stakeholdersupdated the 2004 Standard Practice to keep up with changes in the field and to track new development of health standards. This document superseded the previous version of "CDPH Standard Practice for Testing of VOCs from Various Sources Using Small-scale Environmental Chambers (2004)".
The major changes to the prior document include:
- The title has been changed to Standard Method for the Testing and Evaluation of Volatile Organic Chemical Emissions from Indoor Sources using Environmental Chambers as the document addresses both practice and method as well as testing using chambers of various sizes.
- Adoption of OEHHA's new CRELs to set allowable emission limits. For formaldehyde, it is recommended to continue using one-half of the prior CREL (33 µg m-3) until December 31th, 2011, and the new full CREL (9 µg m-3) starting January 1st, 2012.
- Incorporation of the ANSI/BIFMA M7.1-2007 test and power-law model prediction method as the recognized test method for pupil desks and chairs, open-plan office furniture and office seating, provided that test results meet all the requirements described in this method at 336 hr (14 days).
- Revision of exposure model parameters for the standardized school classroom and the typical office environments, including reference to ASHRAE Standard 62.1-2007 for the outdoor ventilation flow rates.
- Addition of general guidelines to manufacturers and certification/verification organizations for the use of this standard method as the basis for a product-wide claim.
- Revision of specimen collection, preparation and environmental chamber testing in accordance with current best practices.
- Addition of a section on quality management and measurement uncertainty.
- General document clean up.
- Addition of an informative appendix to document a preliminary new single-family residence scenario for IAQ concentration modeling.
It has been more than 6 years since the Indoor Air Quality Program issued the Standard Method for the Testing and Evaluation of VOC Emissions from Indoor Sources Using Environmental Chambers Version 1.1 in 2010. We have been receiving comments regarding potential improvements/updates to this document, one of which is to adopt the new benzene chronic Reference Exposure Level (REL). In this updated version 1.2 (2017), the pass/fail level for benzene emissions has been amended to 1.5 μg/m^3 (½ of current chronic REL), effective on April 01, 2017. This document superseded the previous version of "CDPH Standard Method for the Testing and Evaluation of VOC Emissions from Indoor Sources Using Environmental Chambers Version 1.1 (2010)".
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Material Emission Testing: Certification Programs and Testing Labs
The CDPH Standard Method has been referenced by many widely used green building rating systems, standards and codes, including LEED, IgCC, CalGreen, ASHRAE 189.1 and others. Some of the certification programs and testing labs that provide test service and/or third-party certification based on CDPH Standard Method are listed below:
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