ASTM_E_2079_-_07_2013.pdf

Designation:E207907(Reapproved 2013)Standard Test Methods forLimiting Oxygen(Oxidant)Concentration in Gases andVapors1This standard is issued under the fixed designation E2079;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.1.Scope1.1 These test methods cover the determination of thelimiting oxygen(oxidant)concentration of mixtures of oxygen(oxidant)and inert gases with flammable gases and vapors at aspecified initial pressure and initial temperature.1.2 These test methods may also be used to determine thelimiting concentration of oxidizers other than oxygen.1.3 Differentiation among the different combustion regimes(such as the hot flames,cool flames and exothermic reactions)is beyond the scope of these test methods.1.4 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.5 These test methods should be used to measure anddescribe the properties of materials,products,or assemblies inresponse to heat and flame under controlled laboratory con-ditions and should not be used to describe or appraise the firehazard or fire risk of materials,products,or assemblies underactual fire conditions.However,results of this test may be usedas elements of a fire risk assessment which takes into accountall of the factors which are pertinent to an assessment of thefire hazard of a particular end use.1.6 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 to use.2.Referenced Documents2.1 ASTM Standards:2E1445 Terminology Relating to Hazard Potential of Chemi-cals2.2 NFPA Publication:3NFPA 69 Standard on Explosion Prevention Systems2.3 NTIS Publications:4Bulletin 503 Coward,H.F.,and Jones,G.W.,Bureau ofMines,“Limits of Flammability of Gases and Vapors,”NTIS AD701575,1952Bulletin 627 Zabetakis,M.G.,Bureau of Mines,“Flamma-bility Characteristics of Combustible Gases and Vapors,”NTIS AD701576,1965Bulletin 680 Kuchta,J.M.,Bureau of Mines,“Investigationof Fire and Explosion Accidents in the Chemical,Mining,and Fuel-Related Industries A Manual,”NTISPB87113940,19853.Terminology3.1 DefinitionsSee also Terminology E1445.3.1.1 flammablecapable of propagating a flame.3.1.2 ignitionthe initiation of combustion.3.1.3 limit of flammabilitythe boundary in compositionspace dividing flammable and nonflammable regions.3.1.4 limiting oxygen(oxidant)concentration(LOC)of afuel-oxidant-inert systemthe oxygen(oxidant)concentrationat the limit of flammability for the worst case(most flammable)fuel concentration.3.1.4.1 DiscussionLimiting oxygen(oxidant)concentra-tion is also known as minimum oxygen(oxidant)concentrationor as critical oxygen(oxidant)concentration.4.Summary of Test Method4.1 A mixture containing one or more flammable compo-nents(fuel),oxygen(oxidant)and inert gas(es)(such asnitrogen,carbon dioxide,argon,etc.)is prepared in a suitabletest vessel at a controlled initial temperature and made to thespecified initial pressure.Proportions of the components aredetermined by a suitable means.Ignition of the mixture isattempted and flammability is determined from the pressurerise produced.The criterion for flammability is a pressure rise1These test methods are under the jurisdiction of ASTM Committee E27 onHazard Potential of Chemicals and are the direct responsibility of SubcommitteeE27.04 on Flammability and Ignitability of Chemicals.Current edition approved Oct.1,2013.Published October 2013.Originallyapproved in 2000.Last previous edition approved in 2007 as E2079 07.DOI:10.1520/E2079-07R13.2For 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 Summary page onthe ASTM website.3Available from National Fire Protection Association(NFPA),1 BatterymarchPark,Quincy,MA 02169-7471,http:/www.nfpa.org.4Available from National Technical Information Service(NTIS),5285 PortRoyal Rd.,Springfield,VA 22161,http:/www.ntis.gov.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 of 7%above the initial absolute test pressure.Fuel,oxygen(oxidant),and inert gas proportions are varied between trialsuntil:4.1.1 LThe lowest oxygen(oxidant)concentration forwhich flame propagation is possible for at least one combina-tion of fuel and inert gas(the“worst case”or most flammablefuel concentration range),and4.1.2 HThe highest oxygen(oxidant)concentration forwhich flame propagation is not possible for the same worstcase fuel concentration range,are ide