ASTM_D_4907_-_10_2020.pdf

Designation:D490710(Reapproved 2020)Standard Test Method forNitrocellulose in Finish on Leather1This standard is issued under the fixed designation D4907;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 is intended for use in identifyingnitrocellulose in the finish on all types of leathers.This testmethod does not apply to wet blue.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.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.Significance and Use2.1 This test method is used to identify nitrocellulose infinishes on all types of leathers.3.Apparatus3.1 Borosilicate Glass Watch Glass,100 mm diameter.3.2 Reagent Bottles,two,(4 floz each)equipped with glassjoint dropping pipet.4.Reagents4.1 Indicator solution prepared by dissolving 0.1 g diphe-nylamine in solution containing 100 mL of sulfuric acid and 30mL of distilled water.4.2 Blank solution comprising 100 mL of sulfuric acid and30 mL of distilled water.4.3 Acetone,C.P.4.4 Hazards StatementAll reagents and chemicals shouldbe handled with care.Before using any chemical,read andfollow all safety precautions and instructions on the manufac-turers label or MSDS(Material Safety Data Sheet).5.Test Specimen5.1 The test specimen shall be approximately 1 cm2of thefinished leather.6.Procedure6.1 Place the test specimen in the watch glass with the finishside up.Apply one or 2 mL of indicator solution on the finishand allow to run over the side of the leather on to the watchglass.After 3 min,if the indicator solution does not develop adark blue color,then nitrocellulose is not present in the finish.If the indicator solution develops a dark blue color after contactwith the finish,it indicates the presence of nitrocellulose or hasdeveloped color from colored finish components,or both.6.2 Repeat the above procedure except that the blanksolution is employed instead of the indicator solution.If a darkblue color does not develop,whereas it does when the indicatorsolution is applied,then nitrocellulose is present in the finishand colored finishing materials do not interfere.6.3 If colored finish material develops a dark blue color inthe presence of the blank solution,then place the specimenfinish side up in a watch glass and pour acetone on thespecimen,until completely covered,for dissolving any nitro-cellulose present in the specimen.After allowing the specimento soak in acetone for approximately 2 min,remove thespecimen from the watch glass and the evaporate acetone in thewatch glass on the steam oven to dryness.When cooled toroom temperature,place a few drops of indicator solution onone side of the watch glass near the rim and allow the drops torun downward.At another location on the watch glass,place afew drops of blank solution near the rim and allow to rundownward.If nitrocellulose is present in the finish,a dark bluecolor will develop as the indicator solution runs downward intothe watch glass whereas the blank solution will not show anycolor development.7.Report7.1 The indicator method for testing the presence of nitro-cellulose in finish on the leather shall be reported as positive ornegative.1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.06 on Chemical Analysis Thistest method was developed in cooperation with the American Leather ChemistsAssn.(Method K 5-1956).Current edition approved April 1,2020.Published April 2020.Originallyapproved in 1989.Last previous edition approved in 2015 as D4907 10(2015).DOI:10.1520/D4907-10R20.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.8.Precision and Bias8.1 This test method is adopted from the procedures of theAmerican Leather Chemists Association where it has been inuse and where it