Significance and Use
Objectives—The use of small chambers to evaluate organic emissions from indoor materials has several objectives:
Develop techniques for screening of products for organic emissions;
Determine the effect of environmental variables (that is, temperature, humidity, air exchange) on emission rates;
Rank various products and product types with respect to their emissions profiles (for example, emission factors, specific organic compounds emitted);
Provide compound-specific data on various organic sources to guide field studies and assist in evaluating indoor air quality in buildings;
Provide emissions data for the development and verification of models used to predict indoor concentrations of organic compounds; and
Develop data useful to manufacturers and builders for assessing product emissions and developing control options or improved products.
Mass Transfer Considerations—Small chamber evaluation of emissions from indoor materials requires consideration of the relevant mass transfer processes. Three fundamental processes control the rate of emissions of organic vapors from indoor materials; evaporative mass transfer from the surface of the material to the overlying air, desorption of adsorbed compounds, and diffusion within the material. For more information, refer to Bird, Stewart, and Lightfoot (1960) and Bennett and Myers (1962) in X1.1.
The evaporative mass transfer of a given organic compound from the surface of the material to the overlying air can be expressed as:
Scope
1.1 This guide provides guidance on determination of emissions of organic compounds from indoor materials and products using small-scale environmental test chambers.
1.2 This guide pertains to chambers that fully enclose a material specimen to be tested and does not address other emission chamber designs such as emission cells (see instead Practice D7143).
1.3 As an ASTM standard, this guide describes options, but does not recommend specific courses of action. This guide is not a standard test method and must not be construed as such.
1.4 The use of small environmental test chambers to characterize the organic emissions of indoor materials and products is still evolving. Modifications and variations in equipment, testing procedures, and data analysis are made as the work in the area progresses. For several indoor materials, more detailed ASTM standards for emissions testing have now been developed. Where more detailed ASTM standard practices or methods exist, they supersede this guide and should be used in its place. Until the interested parties agree upon standard testing protocols, differences in approach will occur. This guide will continue to provide assistance by describing equipment and techniques suitable for determining organic emissions from indoor materials. Specific examples are provided to illustrate existing approaches; these examples are not intended to inhibit alternative approaches or techniques that will produce equivalent or superior results.
1.5 Small chambers have obvious limitations. Normally, only samples of larger materials (for example, carpet) are tested. Small chambers are not applicable for testing complete assemblages (for example, furniture). Small chambers are also inappropriate for testing combustion devices (for example, kerosene heaters) or activities (for example, use of aerosol spray products). For some products, small chamber testing may provide only a portion of the emission profile of interest. For example, the rate of emissions from the application of high solvent materials (for example, paints and waxes) via brushing, spraying, rolling, etc. are generally higher than the rate during the drying process. Small chamber testing can not be used to evaluate the application phase of the coating process. Large (or full-scale) chambers may be more appropriate for many of these applications. For guidance on full-scale chamber testing of emissions from indoor materials refer to Practice D6670.
1.6 This guider does not provide specific guidance for the selection of sampling media or for the analysis of volatile organics. This information is provided in Practice D6196.
1.7 The guide does not provide specific guidance for determining emissions of formaldehyde from pressed wood products, since large chamber testing methods for such emissions are well developed and widely used. For more information refer to Test Method E1333. It is possible, however, that the guide could be used to support alternative testing methods.
1.8 This guide is applicable to the determination of emissions from products and materials that may be used indoors. The effects of the emissions (for example, toxicity) are not addressed and are beyond the scope of the guide. Guide D6485 provides an example of the assessment of acute and irritant effects of VOC emissions for a given material. Specification of “target” organic species of concern is similarly beyond the scope of this guide. As guideline levels for specific indoor contaminants develop, so too will emission test protocols to provide relevant information. Emissions databases and material labeling schemes will also be expected to adjust to reflect the current state of knowledge.
1.9 Specifics related to the acquisition, handling, conditioning, preparation, and testing of individual test specimens may vary depending on particular study objectives. Guidelines for these aspects of emissions testing are provided here, specific direction is not mandated. The purpose of this guide is to increase the awareness of the user to available techniques for evaluating organic emissions from indoor materials/products via small chamber testing, to identify the essential aspects of emissions testing that must be controlled and documented, and therefore to provide information, which may lead to further evaluation and standardization.
1.10 Within the context of the limitations discussed in this section, the purpose of this guide is to describe the methods and procedures for determining organic emission rates from indoor materials/products using small environmental test chambers. The techniques described are useful for both routine product testing by manufacturers and testing laboratories and for more rigorous evaluation by indoor air quality (IAQ) researchers. Appendix X1 provides additional references for readers wishing to supplement the information contained in this guide.
1.11 The values stated in SI units are to be regarded as standard.
1.12 This standard does not purport to address the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
