1、Designation: D7706 11Standard Practice forRapid Screening of VOC Emissions from Products UsingMicro-Scale Chambers1This standard is issued under the fixed designation D7706; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、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 practice describes a micro-scale chamber apparatusand associated procedures for rapidly screening materials an
3、dproducts for their vapor-phase emissions of volatile organiccompounds (VOCs) including formaldehyde and other carbo-nyl compounds. It is intended to complement, not replacereference methods for measuring chemical emissions for ex-ample, small-scale chamber tests (Guide D5116) and emissioncell tests
4、 (Practice D7143).1.2 This practice is suitable for use in and outside oflaboratories, in manufacturing sites and in field locations withaccess to electrical power.1.3 Compatible material/product types that may be tested inthe micro-scale chamber apparatus include rigid materials,dried or cured pain
5、ts and coatings, compressible products, andsmall, irregularly-shaped components such as polymer beads.1.4 This practice describes tests to correlate emission resultsobtained from the micro-scale chamber with results obtainedfrom VOC emission reference methods (for example, GuideD5116, Test Method D6
6、007, Practice D7143, and ISO 16000-9and ISO 16000-10).1.5 The micro-scale chamber apparatus operates at moder-ately elevated temperatures, 30C to 60C, to eliminate theneed for cooling, to reduce test times, boost emission rates, andenhance analytical signals for routine emission screening, andto fac
7、ilitate screening of semi-volatile VOC (SVOC) emissionssuch as emissions of some phthalate esters and other plasticiz-ers.1.6 Gas sample collection and chemical analysis are depen-dent upon the nature of the VOCs targeted and are beyond thescope of this practice. However, the procedures described in
8、Test Method D7339, Practice D6196 and ISO 16000-6 foranalysis of VOCs and in Test Method D5197 and ISO 16000-3for analysis of formaldehyde and other carbonyl compoundsare applicable to this practice.1.7 The values stated in SI units are to be regarded asstandard. No other units of measurement are in
9、cluded in thisstandard.1.8 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior
10、 to use.2. Referenced Documents2.1 ASTM Standards:2D1356 Terminology Relating to Sampling and Analysis ofAtmospheresD1914 Practice for Conversion Units and Factors Relatingto Sampling and Analysis of AtmospheresD5116 Guide for Small-Scale Environmental Chamber De-terminations of Organic Emissions fr
11、om Indoor Materials/ProductsD5197 Test Method for Determination of Formaldehydeand Other Carbonyl Compounds in Air (Active SamplerMethodology)D6007 Test Method for Determining Formaldehyde Con-centrations in Air from Wood Products Using a Small-Scale ChamberD6196 Practice for Selection of Sorbents,
12、Sampling, andThermal Desorption Analysis Procedures for Volatile Or-ganic Compounds in AirD5337 Practice for Flow Rate Calibration of PersonalSampling PumpsD7143 Practice for Emission Cells for the Determination ofVolatile Organic Emissions from Indoor Materials/ProductsD7339 Test Method for Determi
13、nation of Volatile OrganicCompounds Emitted from Carpet using a Specific SorbentTube and Thermal Desorption / Gas Chromatography2.2 ISO Standards:3ISO 16000-3 Determination of formaldehyde and othercarbonyl compounds Active sampling methodISO 16000-6 Determination of volatile organic compounds1This
14、practice is under the jurisdiction of ASTM Committee D22 on Air Qualityand is the direct responsibility of Subcommittee D22.05 on Indoor Air.Current edition approved March 1, 2011. Published March 2011.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Serv
15、ice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.1Copyright ASTM International, 1
16、00 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.in indoor and test chamber air by active sampling onTenax TA sorbent, thermal desorption and gas-chromatography using MS/FIDISO 16000-9 Indoor airPart 9: Determination of theemission of volatile organic compounds Emis
17、sion testchamber methodISO 16000-10 Indoor airPart 10: Determination of theemission of volatile organic compounds Emission testcell method2.3 Other Standard:4US EPA Method TO-17 Determination of volatile organiccompounds in ambient air using active sampling ontosorbent tubes3. Terminology3.1 Definit
18、ionsFor definitions and terms commonly usedfor sampling and analysis of atmospheres, refer to TerminologyD1356. For definitions and terms commonly used when testingmaterials and products for VOC emissions, refer to GuideD5116. For an explanation of general units, symbols andconversion factors, refer
19、 to Practice D1914.3.2 Definitions of Terms Specific to This Standard:3.2.1 micro-scale test chamber, nan environmental testchamber ranging in volume from a few milliliters to about 150mL and designed to operate at moderately elevated tempera-tures that is used to measure vapor-phase organic emissio
20、nsfrom small specimens of solid materials and products.3.2.2 control level, na user-defined acceptance criterionfor a micro-scale chamber test, for example, presence orabsence of a target compound and/or a concentration oremission rate of a target compound, typically used in produc-tion quality cont
21、rol to indicate that the tested product samplelikely will meet the corresponding acceptance criterion for areference test.4. Principles4.1 Micro-scale test chambers operate under the same masstransfer principles as conventional small-scale test chambersand cells for measuring emissions of VOCs inclu
22、ding formal-dehyde and other carbonyl compounds from materials andproducts (see Guide D5116 and Practice D7143).4.2 Clean gas (dry nitrogen or air) is supplied to a micro-scale chamber and passes over the exposed surface of the testspecimen before reaching the exhaust point. The gas flow rateand tem
23、perature within the micro-scale chamber are controlled.As the gas passes over the test specimen, emitted compoundsare swept away from the surface.4.3 After the test specimen has equilibrated in the micro-scale chamber (typically for 20-40 minutes), a sampling deviceis connected to the outlet for col
24、lection of vapor-phase com-pounds exiting the chamber.5. Summary of Practice5.1 Micro-scale chambers can be used for rapid screeningand quality control of VOC emissions from many materials andproducts. Compatible sources include (with examples): rigidmaterials (plastics, wood-based panels, hard surf
25、ace flooring),compressible materials (textiles, foams, polymer sheeting),irregularly-shaped materials (polymer components, carpet),and wet-applied products in dried or cured form (for example,paints, coatings, adhesives, caulks, sealants).5.2 Representative test specimens are prepared frommaterial/p
26、roduct samples and are placed directly into micro-scale chambers. For samples that are heterogeneous, it isnecessary to prepare and test replicate specimens. In somecases, it may be necessary to precondition samples or speci-mens prior to testing.5.3 Micro-scale chambers typically are used for measu
27、ringarea-specific emissions from surfaces. They also can be used todetermine mass-, length- or unit-specific emission rates fromvariously shaped test specimens.5.4 Chamber bodies are held at moderately elevated tem-peratures of 30C to 60C and typically are supplied with acontrolled flow of clean, dr
28、y gas, either nitrogen or air.5.5 Specific operating procedures are developed for eachtype of material or product. The key parameters of equilibra-tion time, chamber temperature and inlet gas flow rate areoptimized in an iterative process starting from typical condi-tions and then confirmed by the a
29、nalysis of replicate speci-mens.5.6 Gas samples for VOCs are collected at the exhaust ofthe micro-scale chamber. For ease of use, the entire gas flowexiting the chamber typically passes through the samplingdevice.5.7 A number of gas sampling and analytical methods arecompatible with micro-scale cham
30、bers. VOCs may be col-lected on sorbent tubes and analyzed by thermal desorptiongas chromatography (GC) with mass spectrometry (MS) and/orflame ionization detection (FID) to identify and quantifycompounds as described in Test Method D7339, PracticeD6196, ISO 16000-6 and US EPA Method TO-17. Formalde
31、-hyde and other carbonyl compounds may be sampled andanalyzed as described in Test Method D5197 and ISO 16000-3.Other analytical techniques such as direct-reading instrumentsmay be used if applicable.5.8 This practice describes tests that are used to correlateemission results obtained from micro-sca
32、le chambers to refer-ence results from conventional emission test chambers andcells (that is, Guide D5116, Test Method D6007, PracticeD7143). This relationship is then developed and validated toestablish a control level to evaluate whether the sample islikely to be compliant with guidelines or regul
33、ations for VOCemissions that are determined by a reference methodSeeSection 12.6. Significance and Use6.1 Manufacturers increasingly are being asked or requiredto demonstrate that vapor-phase emissions of chemicals ofconcern from their products under normal use conditionscomply with various voluntar
34、y or regulatory acceptance crite-ria. This process typically requires manufacturers to have theirproducts periodically tested for VOC emissions by independentlaboratories using designated reference test methods (for ex-ample, Test Method D6007, ISO 16000-9, and ISO 16000-10).4Available from United S
35、tates Environmental Protection Agency (EPA), ArielRios Bldg., 1200 Pennsylvania Ave., NW, Washington, DC 20460, http:/www.epa.gov.D7706 112To ensure continuing compliance, manufacturers may opt to, orbe required to, implement screening tests at the productionlevel.6.2 Reference methods for testing c
36、hemical emissions fromproducts are rigorous and typically are too time-consuming andimpractical for routine emission screening in a productionenvironment.6.3 Micro-scale chambers are unique in that their small sizeand operation at moderately elevated temperatures facilitaterapid equilibration and sh
37、ortened testing times. Provided asufficiently repeatable correlation with reference test resultscan be demonstrated, appropriate control levels can be estab-lished and micro-scale chamber data can be used to monitorproduct manufacturing for likely compliance with referenceacceptance criteria. Enhanc
38、ed turnaround time for resultsallows for more timely adjustment of parameters to maintainconsistent production with respect to vapor-phase chemicalemissions.6.4 This practice can also be used to monitor the quality ofraw materials for manufacturing processes.6.5 The use of elevated temperatures addi
39、tionally facilitatesscreening tests for emissions of semi-volatile VOCs (SVOCs)such as some phthalate esters and other plasticizers.7. Apparatus7.1 General Description:7.1.1 The micro-scale chamber test apparatus comprises oneor more micro-scale chambers, a means of incubating themicro-scale chamber
40、(s) at controlled temperature, a regulatedclean gas (nitrogen or air) supply system with optional humidi-fication, gas sampling capabilities, and instrumentation forcontrol, monitoring and recording of conditions.7.1.2 A chamber is typically cylindrical in shape to accom-modate an O-ring seal and ra
41、nges in total volume from a fewmilliliters to about 150 mL depending upon the mode ofoperation, that is, chamber mode for bulk sample emissiontesting and cell mode for surface emission testing of planarspecimens. An example of a typical micro-scale chamberillustrating both modes of operation is show
42、n in Appendix X1.7.1.3 The chamber body and lid assembly are designed to beleak free.7.1.4 A chamber body often has an integral sample holderthat accommodates a planar test specimen such that the backsurface and edges of the specimen are not exposed to the gasstream. The chamber body also can accomm
43、odate irregularlyshaped materials for bulk emission testing.7.1.5 The typical cylindrical shape, small exposed volumeand associated high air change rate of the micro-scale chamber;together with the positioning of the gas inlet and outletperpendicular to the sample surface for a planar specimen(Annex
44、 A) are designed to optimize turbulence, eliminate stillair and ensure thorough mixing of the gas within the chamberat the range of flows specified (see 7.4.4). Typically all of thegas exiting the chamber outlet passes onto the gas samplingdevice, further ensuring representative sampling. Recoveryte
45、sts can be used to demonstrate adequate mixing (see 8.7.1).7.2 Construction:7.2.1 The micro-scale chamber body and associated lid areconstructed of polished or inert-coated stainless steel.7.2.2 The gasket or O-ring used to seal the lid to its body islow absorbing and low emitting at the operating t
46、emperature(#60C) so it does not contribute significantly to backgroundVOC concentrations. (see 10.2) Gaskets and O-rings composedof fluoroelastomer polymers are suitable for this application.7.2.3 The apparatus is designed for easy disassembly tofacilitate cleaning. The chamber body is easily remove
47、d fromthe heater housing and the gasket or O-ring is easily removedfrom the body.7.3 Heating:7.3.1 The chamber body sits in a heater housing that canevenly heat the chamber body and maintain it at controlledtemperatures between 30C and 60C with an accuracy of61C and a precision of 62C at the set tem
48、perature. Themicro-scale chamber lid and air/gas supply also are heated.7.3.2 The apparatus may provide for elevated heating ofchamber bodies to approximately 100C as a cleaning proce-dure.7.4 Gas Supply:7.4.1 The apparatus includes a means of supplying cleangas, either dry nitrogen or air to the ch
49、ambers. Either electronicor mechanical flow controllers are used. The flow rate to eachchamber is individually controlled with an accuracy of 62%and a precision of 63 % of the reading.7.4.2 VOC levels in the gas supply are sufficiently low sothat specified background levels can be achieved (see 10.2.2).7.4.3 For some applications, it may be necessary to providea means of humidifying the inlet gas stream. Water used forhumidification is of sufficient purity such that VOC back-ground requirements (see 10.2.2) can be achieved.7.4.4 Inlet gas flow rates between
