1、Designation: E2892 15Standard Test Method forOdor and Flavor Transfer from Materials in Contact withMunicipal Drinking Water1This standard is issued under the fixed designation E2892; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 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 test method describes procedures for measuringodor and flavor properties of new products which may c
3、omeinto direct contact with municipal drinking water. For thismethod, “drinking water” will be considered water from thesource (for example, river, lake, reservoir) through the munici-pal distribution system (that is, not including in-home orin-business taps). The focus of this test method is the ev
4、alua-tion of the materials in terms of their potential to transfer odors,flavors, or both to water.1.2 This test method provides sample preparationprocedures, methods of sensory evaluation, and a process forinterpretation of results.1.3 This standard does not purport to address all of thesafety conc
5、erns, if any, associated with its use. All materialsthat come into contact with drinking water are required to beapproved through testing by accredited laboratories usingNSF/ANSI Standard 61. It is the responsibility of the user ofthis standard to establish appropriate safety and health prac-tices a
6、nd determine the applicability of regulatory limitationsprior to use.2. Referenced Documents2.1 ASTM Standards:2E253 Terminology Relating to Sensory Evaluation of Mate-rials and ProductsE544 Practices for Referencing Suprathreshold Odor Inten-sityE1885 Test Method for Sensory AnalysisTriangle TestE1
7、870 Test Method for Odor and Taste Transfer fromPolymeric Packaging Film2.2 Other Standards:NSF/ANSI Standard 61 Drinking Water System Compo-nents Health Effects33. Terminology3.1 DefinitionsSee Terminology E253.4. Summary of Test Method4.1 The inherent odor and flavor level of the material isestima
8、ted from the intensities developed upon exposure towater. This method defines the procedure for preparation andevaluation of the material using four steps: (1) Preparation ofcomponent sample; (2) Leaching of sample in extraction water;(3) Sensory analysis; and (4) Data analysis and interpretation.5.
9、 Significance and Use5.1 Many materials that come into contact with drinkingwater have the potential of impacting the aesthetic quality ofthe water. Some of these diverse materials include: storagereservoirs, concrete or metal piping, or both, sealants, syntheticreservoir covers and liners, mending
10、adhesives, gaskets, paints,and plastics. Though NSF Standard 61 provides testing forhealth effects, it does not address taste and odor implications.A Utility Quick Test, Ref (1),4has been proposed, but has notbeen adopted as an official test standard. Taste and odorproblems have been reported as a r
11、esult of organic compoundsleaching from approved materials into water. Materials onlyneed to be tested if they come into direct contact with drinkingwater.6. Testing Facilities and Personnel6.1 All personnel involved in any aspect of the testingshould take precautions to refrain from using personal
12、products(for example, perfume, cologne, scented soaps, food products)which may introduce extraneous odors.6.2 Guidelines for optimal sensory testing location criteriaare detailed in Ref (2). At a minimum, all testing should be1This test method is under the jurisdiction of ASTM Committee E18 on Senso
13、ryEvaluation and is the direct responsibility of Subcommittee E18.06 on Food andBeverage Evaluation.Current edition approved Jan. 1, 2015. Published January 2015. DOI: 10.1520/E2892-15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceast
14、m.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from NSF International, P.O. Box 130140, 789 N. Dixboro Rd., AnnArbor, MI 48113-0140, http:/www.nsf.org.4The boldface numbers in parentheses refer to a list of refer
15、ences at the end ofthis standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1conducted in a location that is odor-free, quiet, temperaturecontrolled, and not used for chemical testing.6.3 This test method is intended for use by tr
16、ained panelsunder leadership of a sensory professional. For discussions ontraining panelists, see Refs (2-4).7. Materials7.1 Blank Water, as odorless and tasteless as possible.Bottled spring water should be assessed by the panel prior touse in testing. If noticeable odor(s) or taste(s) are present,o
17、btain a different lot or brand of water until a suitable productis identified.7.2 Glass Vessel, beaker or equivalent, large enough to holdvolume as determined in Section 10.7.3 Aluminum Foil, uncoated.7.4 Glass Bottles, 1-L with PTFE-lined screw cap forstoring samples prior to sensory analysis.7.5 P
18、lastic Cups, 5 or 6 oz, brand that has been predeter-mined not to impart any interfering odors or flavors to waterthey will contain. Do not use wax coated or paper cups.7.6 Watch Glasses, large enough to cover the cups used inthe method.8. Cleaning Glassware8.1 Use new, clean glassware for each eval
19、uation. Thisglassware must be odor-free and shown not to impart any tasteor odor to the sample during testing. Any caps or liners notmade of glass must be discarded after use since these cannot besufficiently clean for reuse.8.2 If it is not economically practical to use new glasswareeach time, ensu
20、re the glassware is clean and odor-free prior toeach use.8.3 If glassware must be reused, rinse with water immedi-ately after completion of testing. Cleaning should then becompleted by washing with commercial, unscented glasswarewashing detergent to remove any residue. Test the glasswarefor cleanlin
21、ess by rinsing with distilled water and observinghow the water rinses from the surface. The water should sheetoff of the surface rather than form droplets. The exact glass-ware cleaning procedure used must be tested to confirm theglassware will not impart any taste or odor during testing.8.4 Store a
22、ll glassware in a closed cabinet away fromchemical odors to protect from contamination. Glasswarestored upside down or with foil over any openings will preventdust from settling on surfaces.9. Sample Preparation and Cleaning9.1 A representative sample of the material shall be tested.The sample shoul
23、d include all components as intended in thefinal use. Test pieces may be either factory made products orsite-applied products. The material should be tested in tripli-cate (that is, three separate samples of material).9.2 Samples of the test material shall be kept intact as muchas possible (that is,
24、 not cut into fine pieces). Whole componentsshould be used when practical. If component must be cut, onlythe areas that will be in contact with drinking water should beexposed to the test water.9.3 For large components, such as tanks and reservoirs,material samples may be evaluated on behalf of the
25、finishedproduct. Concrete surrogate samples may be evaluated onbehalf of concrete lined pipes and other concrete-based prod-ucts.9.4 Site applied products include coatings, linings, paints,sealants, and solvent cements. These products applied to anappropriate substrate may be evaluated on behalf of
26、compo-nents whose entire water contact surface is covered by thecoating. The manufacturer shall provide detailed applicationinstructions, including: (1) Surface preparation; (2) Mix ratiosand mixing method; (3) Method of application; (4) Minimumcure temperature, time, and conditions; (5) Product fil
27、mthickness; and (6) Associated products, for example, primersand undercoats.9.5 Remove any surface materials (labels, tape, etc); do notuse soaps or solvents.9.6 Rinse with blank water.9.7 Condition the material to be tested by soaking it in blankwater for a defined period of time depending on the m
28、aterialand its use. See NSF/ANSI 61 and Refs (5 and 6).9.8 Disinfection:9.8.1 Note that disinfection may impact the sensory analy-sis. Conduct aroma analysis on the sample prior to disinfection.9.8.2 Disinfect sample by soaking for three hours in aque-ous solution (using blank water) of 50 mg/L chlo
29、rine; rinsewith blank water until wash water contains 0.5 mg/L chlorine.9.8.3 Repeat the aroma analysis on the disinfected sample.If the aroma characteristics are significantly different from theoriginal sample, the user must determine if this test is appro-priate for their purposes.9.8.4 If the aro
30、ma analysis on the disinfected and non-disinfected sample are comparable, proceed with flavor analy-sis.10. Exposure Method10.1 Use blank water as defined in 7.1 for all leachingprocedures.10.2 A method blank shall be processed in the same manneras the samples, using the same blank water, but withou
31、taddition of the test material.10.3 All samples should be prepared in triplicate (that is,three separate pieces of material to be leached in threecontainers of blank water).10.4 The test shall be conducted using a 24-h exposureperiod. Alternate exposure times may be used to better repli-cate operati
32、onal use of the product.10.5 Surface area to volume ratio should be at least 15cm2/L or greater. For guidance on proper surface to volumeratios for particular material types, see NSF/ANSI Standard 61and Refs (1, 5 and 6). The entire surface of the sample shouldbe covered by the extraction water. The
33、 extraction vesselE2892 152should be covered with clean aluminum foil and stored atambient temperature (25 6 2C).10.6 At the end of the leaching period, the water (leachate)should be decanted into 1-L glass bottles with no headspaceand sealed with PTFE-lined caps. Store samples at 4C untiltime of an
34、alysis. Analysis should be conducted within 48hours.11. Sensory Method11.1 The recommended method is the Standard Method2170 Flavor Profile Analysis published in Ref (7), which isbased on Flavor Profile Method inASTM Manual 26 (2). Referto Standard Method 2170 for details on the analysis. Thisdescri
35、ptive method is preferred over triangle difference tests(Test Method E1885) or threshold odor number (TON, Stan-dard Method 2150B, Ref (7) because it is a direct measure-ment of the contaminating attribute and an overall differencefrom the blank water. Other descriptive methods may be used;however,
36、the Standard Method 2170 is currently the methodused by the drinking water industry, and the use of a singletechnique provides consistency among sensory panels.11.2 The flavor intensity scale is shown in Appendix X1.Anodor intensity scale spanning the typical drinking water inten-sity range (8) is s
37、hown in Appendix X2. Additional practice tohelp understand odor intensity can be conducted using thebutanol scale (Practices E544).NOTE 1This practice is for aroma only.11.3 Use an experienced panel of five assessors who aretrained in this method, but no fewer than three; see Refs (2-4,9). Assessors
38、 should be selected for their ability to identifyodors and flavors, rank intensities, and communicate percep-tions.11.4 Provide a score sheet with a short list of commonattributes, plus write-in spaces. Common sources of off-odorsand flavors along with their sensory descriptors can be found inTest M
39、ethod E1870. See Appendix X3 for an example scoresheet.11.5 Routine and random blind controls and blank waterspiked with a reference standard to an intensity of just greaterthan “slight” should be included with the test samples (forexample, styrene at 100 ppb or dimethyl styrene at 120 ppb).11.6 Sam
40、ple temperature is 25C. Samples should be ana-lyzed in the order presented. A known blank control may beused as a reference. Samples should be in cups that have beenpreviously determined not to have any off-odors or off-flavorsthat will interfere with the analysis. Samples should be pouredinto the c
41、up (approximately 30 mL of sample) and coveredimmediately with a watch glass.11.7 Assessors should conduct odor analysis first. If theodor analysis fails the test, no flavor analysis should beconducted.11.7.1 Gently swirl the cup on the table to release odors intothe headspace.11.7.2 Move the watch
42、glass back slightly and, keepinghands away from the cup, assess the aroma by taking a fewshort sniffs. Rest for 10 to 15 s between samples. Repeat ifnecessary to decide on the descriptors, but the intensity ratingshould be decided on the first sniff.11.7.3 Record each odor attribute on the score she
43、et (Ap-pendix X3) with a corresponding intensity (Appendix X1,Appendix X2).11.7.4 Assess odor for all samples; do not discuss with otherpanelists until the time for discussion.11.8 If the odor test passes, follow with flavor analysis.11.8.1 Take approximately 10 mL of water into the mouthand roll it
44、 over entire tongue. Slurping may enhance the flavorassessment; the panel should decide upon the technique prior toassessment.11.8.2 Swallow slowly. Alternatively, the panel may decideprior to assessment to expectorate the sample.11.8.3 Record each flavor attribute with a correspondingintensity.11.8
45、.4 Do not discuss with other panelists until the time fordiscussion.11.9 The panel discusses and comes to a consensus agree-ment on the intensity of each attribute.12. Data Interpretation12.1 Interpretation of the data is based on the intensityrating of the consensus profile. The consensus score sho
46、uld becompared to the control sample (method blank).12.2 Historically, attributes in drinking water that are rankedwith an intensity greater than “slight” have triggered consumercomplaints (10 and 11). Therefore, leachate water with norecorded attribute intensities greater than “slight” shall becons
47、idered as passing the test. Leachate waters with attributeintensities greater than slight shall be considered to have failedthe test.12.3 All three replicates must pass for the material to passthe test.13. Recommendation13.1 Materials that pass this test are considered acceptablefor use in applicati
48、ons in direct contact with drinking water.14. Reporting14.1 A final test report shall include the following (examplein Appendix X4):14.1.1 A unique test report number and date of the test.14.1.2 References to standards utilized in the test.14.1.3 A clear description of the tested material.14.1.4 Det
49、ailed description of the procedures used for thesample preparation, including procedures for disinfecting orconditioning of the materials as well as details regarding theexposure methodology, such as surface to volume ratio andcontact time and temperature.14.1.5 Number of assessors used.14.1.6 Results of the testing displayed as consensus scoresfrom the assessors.15. Precision and Bias15.1 Because results of sensory tests are functions ofindividual sensitivities, a general statement regarding theE2892 153precision of results that is applicable to all populations ofassessor
