ASTM_D_4575_-_09_2019.pdf

Designation:D457509(Reapproved 2019)Standard Test Methods forRubber DeteriorationReference and Alternative Method(s)for Determining Ozone Level in Laboratory Test Chambers1This standard is issued under the fixed designation D4575;the number immediately following the designation indicates the year oforiginal adoption or,in the case 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.INTRODUCTIONNumerous techniques exist for the analysis of gaseous ozone in ozone-air mixtures used for ozonecrack testing of rubber.These include wet chemical procedures,electrochemical cells,UV absorption,and chemiluminescence with ethylene.See Refs(1-4).2Wet chemical methods(the absorption of ozone in a potassium iodide solution and titration of theiodine released with sodium thiosulfate)have been in traditional use in the rubber industry,but theyare not suitable for continuous operation,and in recent years they have been shown to be sensitive tosmall variations in test procedures and concentration and purity of reagents.Interlaboratory tests haveindicated that different procedures do not give equivalent results,and most of them differ from anabsolute UV method.Frequently,wet chemical methods yield higher ozone concentrations due to theoxidizing capacity of other components of the ozone-air mixture.Certain nonreference instrumental methods are amenable to automatic operation and for this reasonthey are included in this standard.They may be used for routine testing once calibrated against thereference UV method.UV absorption is adopted as the reference method against which the others shall be calibrated.Itis an absolute test method and is in common use by environmental protection agencies for thedetermination of pollutant ozone in air(see 2.3).Although these test methods are concerned with ozone analysis,it also draws attention to theinfluence of atmospheric pressure on the rate of cracking of rubber at constant ozone concentration asnormally expressed in terms of parts by volume.As described in Appendix X2,the variation in ozoneresistance that can result between laboratories operating at significantly different atmosphericpressures can be eliminated by specifying ozone concentration in terms of the partial pressure ofozone.1.Scope1.1 These test methods cover the following three types ofmethods for the determination of ozone content in laboratorytest chambers.Method A(UV absorption)is specified forreference or referee purposes and as a means of calibration forthe alternative methods;Method B,instrumental device(elec-trochemical or chemiluminescence);and Method C,wetchemical techniques(see Appendix X1).These methods areprimarily intended for use with tests for determining rubberozone cracking resistance and thus are applicable over theozone level range from 25 to 200 mPa.NOTE1Prior to 1978,ozone concentrations were expressed in ASTMD11 Standards in parts per hundred million(pphm)of air by volume.SeeAppendix X2 for an explanation of the change to partial pressure inmillipascals(mPa).1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.3 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.For a specific hazard statement,see Note 2 and 5.1.NOTE2WarningOzone is a hazardous chemical.1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and Rubber-like Materials and are the direct responsibility of SubcommitteeD11.15 on Degradation Tests.Current edition approved Nov.1,2019.Published December 2019.Originallyapproved in 1986.Last previous edition approved in 2015 as D4575 09(2015).DOI:10.1520/D4575-09R19.2The boldface numbers in parentheses refer to the list of references at the end ofthis standard.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:3D518 Test Method for Rubber DeteriorationSurfaceCracking(Withdrawn 2007)4D1149 Test Methods for Rubber De