ASTM_G_125_-_00_2015.pdf

Designation:G12500(Reapproved 2015)Standard Test Method forMeasuring Liquid and Solid Material Fire Limits in GaseousOxidants1This standard is issued under the fixed designation G125;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 This test method covers a procedure for measuring thethreshold-limit conditions to allow equilibrium of combustionof materials in various oxidant gases under specific testconditions of pressure,temperature,flow condition,fire-propagation directions,and various other geometrical featuresof common systems.1.2 This test method is patterned after Test MethodD2863-95 and incorporates its procedure for measuring thelimit as a function of oxidant concentration for the mostcommonly used test conditions.Sections 8,9,10,11,13,andfor the basic oxidant limit(oxygen index)procedure are quoteddirectly from Test Method D2863-95.Oxygen index datareported in accordance with Test Method D2863-95 are accept-able substitutes for data collected with this standard undersimilar conditions.1.3 This test method has been found applicable to testingand ranking various forms of materials.It has also foundlimited usefulness for surmising the prospect that materials willprove“oxygen compatible”in actual systems.However,itsresults do not necessarily apply to any condition that does notfaithfully reproduce the conditions during test.The fire limit isa measurement of a behavioral property and not a physicalproperty.Uses of these data are addressed in Guides G63 andG94.NOTE1Although this test method has been found applicable fortesting a range of materials in a range of oxidants with a range of diluents,the accuracy has not been determined for many of these combinations andconditions of specimen geometry,outside those of the basic procedure asapplied to plastics.NOTE2Test Method D2863-95 has been revised and the revised TestMethod has been issued as D2863-97.The major changes involve sampledimensions,burning criteria and the method for determining the oxygenindex.The aim of the revisions was to align Test Method D2863 with ISO4589-2.Six laboratories conducted comparison round robin testing onself-supporting plastics and cellular materials using D2863-95 and D2863-97.The results indicate that there is no difference between the meansprovided y the two methods at the 95%confidence level.No comparisontests were conducted on thin films.The majority of ASTM Committee G4favors maintaining the D2863-95 as the backbone of G125 until compre-hensive comparison data become available.1.4 One very specific set of test conditions for measuringthe fire limits of metals in oxygen has been codified in TestMethod G124.Test Method G124 measures the minimumpressure limit in oxygen for its own set of test conditions.Itsdetails are not reproduced in this standard.A substantialdatabase is available for this procedure,although it is muchsmaller than the database for Test Method D2863-95.(WarningDuring the course of combustion,gases,vapors,aerosols,fumes or any combination of these are evolved whichmay be hazardous.)(WarningAdequate precautions shouldbe taken to protect the operator.)1.5 The values stated in SI units are to be regarded as thestandard.No other units of measurement are included in thisstandard.1.6 This basic standard 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 directly describe or appraisethe fire hazard or fire risk of materials,products or assembliesunder actual fire conditions.However,results of this test maybe used as elements of a fire risk assessment which takes intoaccount all of the factors which are pertinent to an assessmentof the fire hazard of a particular end use.The standard hasmore applicability in this regard at predicting the fire behaviorof materials and components that are close in size to the testcondition,than for systems that are much different(for ex-ample:comparing a test rod to a valve seat rather thancomparing a test rod to a house or a particle).1.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is the1This test method is under the jurisdiction of ASTM Committee G04 onCompatibility and Sensitivity of Materials in Oxygen Enriched Atmospheres and isthe direct responsibility of Subcommittee G04.01 on Test Methods.Portions havebeen adopted from Test Method D2863-95,which is under the jurisdiction ofASTMCommittee D20 on Plastics.Current edition approved Oct.1,2015.Published October 2015.Originallyapproved in 1994.Last previous edition approved in 2000 as G125 00(2008).DOI:10.1520/G0125-00R15.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Co