1、Designation: D5116 10Standard Guide forSmall-Scale Environmental Chamber Determinations ofOrganic Emissions from Indoor Materials/Products1This standard is issued under the fixed designation D5116; the number immediately following the designation indicates the year oforiginal adoption or, in the cas
2、e of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 indoo
3、r 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 D7143).1.3 As an ASTM standard, this guide des
4、cribes 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 var
5、iations 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 and
6、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 are
7、 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. Small c
8、hambers 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 only
9、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 toeva
10、luate 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 D6670.1.6 This guider does not provide specific guidance for thesele
11、ction of sampling media or for the analysis of volatileorganics. This information is provided in Practice D6196.1.7 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 well deve
12、loped and widely used. For more informationrefer to Test Method E1333. 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 of the e
13、missions (for example, toxicity) are notaddressed and are beyond the scope of the guide. Guide D6485provides 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 this guide
14、. 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 acquisition, han
15、dling, 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 user to av
16、ailable 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 standardization.1.10
17、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 Air Qua
18、lityand is the direct responsibility of Subcommittee D22.05 on Indoor Air.Current edition approved April 1, 2010. Published April 2010. Originallyapproved in 1990. Last previous edition approved in 2006 as D5116 - 06. DOI:10.1520/D5116-10.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box
19、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. Appendix X1 provides additional references forreaders
20、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 the user of this standard to establish appropri
21、ate safety andhealth practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD1356 Terminology Relating to Sampling and Analysis ofAtmospheresD1914 Practice for Conversion Units and Factors Relati
22、ngto Sampling and Analysis of AtmospheresD3195 Practice for Rotameter CalibrationD3609 Practice for Calibration Techniques Using Perme-ation TubesD3686 Practice for Sampling Atmospheres to Collect Or-ganic Compound Vapors (Activated Charcoal Tube Ad-sorption Method)D3687 Practice for Analysis of Org
23、anic Compound VaporsCollected by the Activated Charcoal Tube AdsorptionMethodD6177 Practice for Determining Emission Profiles of Vola-tile Organic Chemicals Emitted from Bedding SetsD6196 Practice for Selection of Sorbents, Sampling, andThermal Desorption Analysis Procedures for Volatile Or-ganic Co
24、mpounds in AirD6330 Practice for Determination of Volatile Organic Com-pounds (Excluding Formaldehyde) Emissions from Wood-Based Panels Using Small Environmental Chambers Un-der Defined Test ConditionsD6485 Guide for Risk Characterization ofAcute and IrritantEffects of Short-Term Exposure to Volatil
25、e OrganicChemicals Emitted from Bedding SetsD6670 Practice for Full-Scale Chamber Determination ofVolatile Organic Emissions from Indoor Materials/ProductsD6803 Practice for Testing and Sampling of Volatile Or-ganic Compounds (Including Carbonyl Compounds) Emit-ted from Paint Using Small Environment
26、al ChambersD7143 Practice for Emission Cells for the Determination ofVolatile Organic Emissions from Indoor Materials/ProductsE355 Practice for Gas Chromatography Terms and Rela-tionshipsE1333 Test Method for Determining Formaldehyde Con-centrations inAir and Emission Rates from Wood ProductsUsing a
27、 Large Chamber3. Terminology3.1 DefinitionsFor definitions and terms used in thisguide, refer to Terminology D1356. For an explanation ofunits, symbols, and conversion factors, refer to Practice D1914.3.2 Definitions of Terms Specific to This Standard:3.2.1 air change ratethe flow rate of clean, con
28、ditionedair into the chamber divided by the chamber volume; usuallyexpressed in units 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 Dis
29、cussionThese chambers are designed to permittesting of emissions from samples of building 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 evaluateorga
30、nic emissions from indoor materials has several objectives:4.1.1 Develop techniques 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
31、respectto their emissions profiles (for example, emission factors,specific organic compounds 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 ver
32、i-fication of models used to predict indoor concentrations oforganic compounds; and4.1.6 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 ind
33、oor materials requires considerationof the relevant mass transfer processes. Three fundamentalprocesses 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
34、 within the material. For moreinformation, refer to Bird, Stewart, and Lightfoot (1960) 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
35、rate,km = mass transfer coefficient,VPs = vapor pressure at the surface of the material, and2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document S
36、ummary page onthe ASTM website.D5116 102VPa = 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 propor
37、tional to the difference in concentrationbetween 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.4.2.2 The desorption rate of compounds adsorbed on mate-r
38、ials can be determined by the retention time (or averageresidence time) of an adsorbed 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 = t
39、emperature, K.The larger the retention time, the slower the rate of desorp-tion.4.2.3 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 functi
40、on of the compoundsphysical and chemical properties (for example, molecularweight, size, 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
41、Variables Affecting Mass TransferWhile a detaileddiscussion of mass transfer theory is 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, a
42、nd the diffusion coefficients of the organic compounds.Thus, temperature impacts both 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 transfer
43、processes.4.2.4.2 Air change rate is flow of outdoor air entering theindoor environment 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
44、 greaterthe dilution, assuming the indoor air is cleaner, and the lowerthe concentration. 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
45、air.4.2.4.3 Air VelocityThe mass transfer coefficient (km)isaffected by the velocity 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 c
46、ertainvelocity and level of turbulence, the resistance to mass transferthrough the boundary 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
47、surface. Forexample, air velocities of 0.3 to 0.5 m/s have been used inevaluating formaldehyde 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 m
48、edian of0.05 m/s. Thus, other investigators prefer to keep the velocitiesin the range 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-pou
49、nds emitted from indoor materials and products are non-reactive, and chambers are designed 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 simultaneous 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 a
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