This practice is recommended for use in measuring the concentration of VOCs in ambient, indoor, and workplace atmospheres. It may also be used for measuring emissions from materials in small or full scale environmental chambers for material emission testing or human exposure assessment.
Such measurements in ambient air are of importance because of the known role of VOCs as ozone precursors, and in some cases (for example, benzene), as toxic pollutants in their own right.
Such measurements in indoor air are of importance because of the association of VOCs with air quality problems in indoor environments, particularly in relation to sick building syndrome and emissions from building materials. Many volatile organic compounds have the potential to contribute to air quality problems in indoor environments and in some cases toxic VOCs may be present at such elevated concentrations in home or workplace atmospheres as to prompt serious concerns over human exposure and adverse health effects (6).
Such measurements in workplace air are of importance because of the known toxic effects of many such compounds.
In all three environments, in order to protect the environment as a whole and human health in particular, it is necessary to take measurements of air quality as part of an overall assessment in relation to mandatory requirements.
The choices of sorbents, sampling method, and analytical methodology affect the efficiency of sorption, recovery, and quantification of individual VOCs. This practice is potentially effective for a wide range of volatile organic compounds found in air, over a wide range of volatilities and concentration levels. However, it is the responsibility of the user to ensure that the sampling, recovery, analysis, and quality control for the measurement of a specific VOC of interest are within acceptable limits. Guidance for this evaluation is part of the scope of this practice.
1.1 This practice is intended to assist in the selection of sorbents and procedures for the sampling and analysis of ambient (1) , indoor (2) and workplace (3, 4) atmospheres for a variety of common volatile organic compounds (VOCs). It may also be used for measuring emissions from materials in small or full scale environmental chambers or for human exposure assessment.
1.2 A complete listing of VOCs for which this practice has been tested, at least over part of the measurement range (1.6), is shown in Tables 1-9. For other compounds this practice shall be tested according to EN 1076 (pumped); Practice D 6246, ISO 16107, ANSI/ISEA 104, EN 838 or EN 13528-1/EN 13528-2 (diffusive); or other appropriate validation protocols (Sections 13 and 14). (5,1)
1.3 This practice is based on the sorption of VOCs from air onto selected sorbents or combinations of sorbents. Sampled air is either drawn through a tube containing one or a series of sorbents (pumped sampling) or allowed to diffuse, under controlled conditions, onto the sorbent tube or tubes (diffusive or passive sampling). The sorbed VOCs are subsequently recovered by thermal desorption and analyzed by capillary gas chromatography.
1.4 This practice applies to three basic types of samplers that are compatible with thermal desorption: (1) pumped sorbent tubes containing one or more sorbents; (2) axial diffusive samplers (typically of the same physical dimensions as standard pumped sorbent tubes and containing only one sorbent); and (3) radial diffusive samplers.
1.5 This practice recommends a number of sorbents that can be packed in sorbent tubes, for use in the sampling of a wide range of different volatile organic compounds boiling in the ran......
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