1、Designation: D 5116 06Standard Guide forSmall-Scale Environmental Chamber Determinations ofOrganic Emissions From Indoor Materials/Products1This standard is issued under the fixed designation D 5116; the number immediately following the designation indicates the year oforiginal adoption or, in the c
2、ase of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide provides guidance on determination of emis-sions of organic compounds from in
3、door materials and prod-ucts using small-scale environmental test chambers.1.2 This guide pertains to chambers that fully enclose amaterial specimen to be tested and does not address otheremission chamber designs such as emission cells (see insteadPractice D 7143).1.3 As an ASTM standard, this guide
4、 describes options, butdoes not recommend specific courses of action. This guide isnot a standard test method and must not be construed as such.1.4 The use of small environmental test chambers to char-acterize the organic emissions of indoor materials and productsis still evolving. Modifications and
5、 variations in equipment,testing procedures, and data analysis are made as the work inthe area progresses. For several indoor materials, more detailedASTM standards for emissions testing have now been devel-oped. Where more detailed ASTM standard practices ormethods exist, they supersede this guide
6、and should be used inits place. Until the interested parties agree upon standardtesting protocols, differences in approach will occur.This guidewill continue to provide assistance by describing equipmentand techniques suitable for determining organic emissionsfrom indoor materials. Specific examples
7、 are provided toillustrate existing approaches; these examples are not intendedto inhibit alternative approaches or techniques that will pro-duce equivalent or superior results.1.5 Small chambers have obvious limitations. Normally,only samples of larger materials (for example, carpet) aretested. Sma
8、ll chambers are not applicable for testing completeassemblages (for example, furniture). Small chambers are alsoinappropriate for testing combustion devices (for example,kerosene heaters) or activities (for example, use of aerosolspray products). For some products, small chamber testing mayprovide o
9、nly a portion of the emission profile of interest. Forexample, the rate of emissions from the application of highsolvent materials (for example, paints and waxes) via brushing,spraying, rolling, etc. are generally higher than the rate duringthe drying process. Small chamber testing can not be used t
10、oevaluate the application phase of the coating process. Large (orfull-scale) chambers may be more appropriate for many ofthese applications. For guidance on full-scale chamber testingof emissions from indoor materials refer to Practice D 6670.1.6 This guider does not provide specific guidance for th
11、eselection of sampling media or for the analysis of volatileorganics. This information is provided in Practice D 6196.1.7 The guide does not provide specific guidance for deter-mining emissions of formaldehyde from pressed wood prod-ucts, since large chamber testing methods for such emissionsare wel
12、l developed and widely used. For more informationrefer to Test Method E 1333. It is possible, however, that theguide could be used to support alternative testing methods.1.8 This guide is applicable to the determination of emis-sions from products and materials that may be used indoors.The effects o
13、f the emissions (for example, toxicity) are notaddressed and are beyond the scope of the guide. Guide D 6485provides an example of the assessment of acute and irritanteffects of VOC emissions for a given material. Specification of“target” organic species of concern is similarly beyond thescope of th
14、is guide. As guideline levels for specific indoorcontaminants develop, so too will emission test protocols toprovide relevant information. Emissions databases and mate-rial labeling schemes will also be expected to adjust to reflectthe current state of knowledge.1.9 Specifics related to the acquisit
15、ion, handling, condition-ing, preparation, and testing of individual test specimens mayvary depending on particular study objectives. Guidelines forthese aspects of emissions testing are provided here, specificdirection is not mandated. The purpose of this guide is toincrease the awareness of the us
16、er to available techniques forevaluating organic emissions from indoor materials/productsvia small chamber testing, to identify the essential aspects ofemissions testing that must be controlled and documented, andtherefore to provide information, which may lead to furtherevaluation and standardizati
17、on.1.10 Within the context of the limitations discussed in thissection, the purpose of this guide is to describe the methodsand procedures for determining organic emission rates fromindoor materials/products using small environmental test1This guide is under the jurisdiction of ASTM Committee D22 on
18、 Air Qualityand is the direct responsibility of Subcommittee D22.05 on Indoor Air.Current edition approved April 1, 2006. Published May 2006. Originallyapproved in 1990. Last previous edition approved in 1997 as D 5116 - 97, whichwas withdrawn January 2006 and reinstated in April 2006.1Copyright AST
19、M International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.chambers. The techniques described are useful for both routineproduct testing by manufacturers and testing laboratories andfor more rigorous evaluation by indoor air quality (IAQ)researchers. Appendi
20、x X1 provides additional references forreaders wishing to supplement the information contained inthis guide.1.11 The values stated in SI units are to be regarded asstandard.1.12 This standard does not purport to address the safetyconcerns, if any, associated with its use. It is the responsibilityof
21、the user of this standard to establish appropriate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1193 Specification for Reagent WaterD 1356 Terminology Relating to Sampling and Analysis ofAtmospheresD 191
22、4 Practice for Conversion Units and Factors Relatingto Sampling and Analysis of AtmospheresD 3195 Practice for Rotameter CalibrationD 3609 Practice for Calibration Techniques Using Perme-ation TubesD 3686 Practice for Sampling Atmospheres to Collect Or-ganic Compound Vapors (Activated Charcoal Tube
23、Ad-sorption Method)D 3687 Practice for Analysis of Organic Compound VaporsCollected by the Activated Charcoal Tube AdsorptionMethodD 6196 Practice for Selection of Sorbents, Sampling, andThermal Desorption Analysis Procedures for Volatile Or-ganic Compounds in AirD 6485 Guide for Risk Characterizati
24、on of Acute and Irri-tant Effects of Short-Term Exposure to Volatile OrganicChemicals Emitted from Bedding SetsD 6670 Practice for Full-Scale Chamber Determination ofVolatile Organic Emissions from Indoor Materials/ProductsD 7143 Practice for Emission Cells for the Determination ofVolatile Organic E
25、missions from Indoor Materials/ProductsE 355 Practice for Gas Chromatography Terms and Rela-tionshipsE 1333 Test Method for Determining Formaldehyde Con-centrations inAir and Emission Rates from Wood ProductsUsing a Large Chamber3. Terminology3.1 DefinitionsFor definitions and terms used in thisguid
26、e, refer to Terminology D 1356. For an explanation ofunits, symbols, and conversion factors, refer to PracticeD 1914.3.2 Definitions of Terms Specific to This Standard:3.2.1 air change ratethe flow rate of clean, conditionedair into the chamber divided by the chamber volume; usuallyexpressed in unit
27、s of h1.3.2.2 product loadingthe ratio of the test specimen area tothe chamber volume.3.2.3 test chamberan enclosed test volume constructed ofchemically inert materials with a clean air supply and exhaust.3.2.3.1 DiscussionThese chambers are designed to permittesting of emissions from samples of bui
28、lding materials andconsumer products. The internal volume of small-scale cham-bers usually ranges from a few litres to a few cubic metres.4. Significance and Use4.1 ObjectivesThe use of small chambers to evaluateorganic emissions from indoor materials has several objectives:4.1.1 Develop techniques
29、for screening of products fororganic emissions;4.1.2 Determine the effect of environmental variables (thatis, temperature, humidity, air exchange) on emission rates;4.1.3 Rank various products and product types with respectto their emissions profiles (for example, emission factors,specific organic c
30、ompounds emitted);4.1.4 Provide compound-specific data on various organicsources to guide field studies and assist in evaluating indoor airquality in buildings;4.1.5 Provide emissions data for the development and veri-fication of models used to predict indoor concentrations oforganic compounds; and4
31、.1.6 Develop data useful to manufacturers and builders forassessing product emissions and developing control options orimproved products.4.2 Mass Transfer ConsiderationsSmall chamber evalua-tion of emissions from indoor materials requires considerationof the relevant mass transfer processes. Three f
32、undamentalprocesses control the rate of emissions of organic vapors fromindoor materials; evaporative mass transfer from the surface ofthe material to the overlying air, desorption of adsorbedcompounds, and diffusion within the material. For moreinformation, refer to Bird, Stewart, and Lightfoot (19
33、60) andBennett and Myers (1962) in X1.1.4.2.1 The evaporative mass transfer of a given organiccompound from the surface of the material to the overlying aircan be expressed as:E 5 km VPs 2 VPa! (1)where:E = emission rate,km = mass transfer coefficient,VPs = vapor pressure at the surface of the mater
34、ial, andVPa = vapor pressure in the air above the surface.Thus, the emission rate is proportional to the difference invapor pressure between the surface and the overlying air. Sincethe vapor pressure is directly related to the concentration, theemission rate is proportional to the difference in conc
35、entrationbetween the surface and the overlying air. The mass transfercoefficient is a function of the diffusion coefficient (in air) forthe specific compound of interest, the level of turbulence in thebulk flow.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Cust
36、omer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.D51160624.2.2 The desorption rate of compounds adsorbed on mate-rials can be determined by the retention time (or averageresidence time) of an adsorbe
37、d molecule:t5toe2Q/RT(2)where:t = retention time, s,to= constant with a typical value from 1012to 1015s,Q = molar enthalpy change for adsorption (or adsorptionenergy), J/mol,R = gas constant, 8.314 J/mol-K, andT = temperature, K.The larger the retention time, the slower the rate of desorp-tion.4.2.3
38、 The diffusion mass transfer within the material is afunction of the diffusion coefficient (or diffusivity) of thespecific compound. The diffusion coefficient of a given com-pound within a given material is a function of the compoundsphysical and chemical properties (for example, molecularweight, si
39、ze, and polarity), temperature, and the structure of thematerial within which the diffusion is occurring.The diffusivityof an individual compound in a mixture is also affected by thecomposition of the mixture.4.2.4 Variables Affecting Mass TransferWhile a detaileddiscussion of mass transfer theory i
40、s beyond the scope of thisguide, it is necessary to examine the critical variables affectingmass transfer within the context of small chamber testing:4.2.4.1 Temperature affects the vapor pressure, desorptionrate, and the diffusion coefficients of the organic compounds.Thus, temperature impacts both
41、 the mass transfer from thesurface (whether by evaporation or desorption) and the diffu-sion mass transfer within the material. Increases in temperaturecause increases in the emissions due to all three mass transferprocesses.4.2.4.2 Air change rate is flow of outdoor air entering theindoor environme
42、nt divided by the volume of the indoor space,usually expressed in units of h1. The air exchange rateindicates the amount of dilution and flushing that occurs inindoor environments. The higher the air change rate the greaterthe dilution, assuming the indoor air is cleaner, and the lowerthe concentrat
43、ion. If the concentration at the surface is un-changed, a lower concentration in the air increases the evapo-rative mass transfer by increasing the difference in concentra-tion between the surface and the overlying air.4.2.4.3 Air VelocityThe mass transfer coefficient (km)isaffected by the velocity
44、in the boundary layer above the surfaceand the level of turbulence. Generally, the higher the velocityand the higher the level of turbulence, the greater the masstransfer coefficient. In a practical sense, above a certainvelocity and level of turbulence, the resistance to mass transferthrough the bo
45、undary layer is minimized (that is, the masstransfer coefficient reaches its maximum value). In chambertesting, some investigators prefer to use velocities high enoughto minimize the mass transfer resistance at the surface. Forexample, air velocities of 0.3 to 0.5 m/s have been used inevaluating for
46、maldehyde emissions from wood products. Suchvelocities are higher than those observed in normal residentialenvironments by Matthews et al.,3where in six houses theyobserved velocities with a mean of 0.07 m/s and a median of0.05 m/s. Thus, other investigators prefer to keep the velocitiesin the range
47、 normally found indoors. In either case, anunderstanding of the effect of velocity on the emission rate isneeded in interpreting small chamber emissions data.4.3 Other Factors Affecting EmissionsMost organic com-pounds emitted from indoor materials and products are non-reactive, and chambers are des
48、igned to reduce or eliminatereactions and adsorption on the chamber surfaces (see 5.2.1).In some cases, however, surface adsorption can occur. Somerelatively high molecular weight, high boiling compounds canreact (that is, with ozone) after being deposited on the surface.In such cases, the simultane
49、ous degradation and buildup on andthe ultimate re-emission from the chamber walls can affect thefinal chamber concentration and the time history of theemission profile. Unless such factors are properly accountedfor, incorrect values for the emission rates will be calculated(see 9.4). The magnitude of chamber adsorption and reactioneffects can be evaluated by way of mass balance calculations(see 9.5). For further information on these processes seeJayjock, et al. (X1.1).4.4 Use of the ResultsIt is emphasized that small chamberevaluations are used to determine source emiss
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