ASTM_D_7558_-_09_2014.pdf

Designation:D755809(Reapproved 2014)Standard Test Method forColorimetric/Spectrophotometric Procedure to QuantifyExtractable Chemical Dialkyldithiocarbamate,Thiuram,andMercaptobenzothiazole Accelerators in Natural RubberLatex and Nitrile Gloves1This standard is issued under the fixed designation D7558;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 designed to quantify the amount oftotal extractable accelerators in natural rubber latex(NRL)andnitrile gloves.Three common classes of rubber accelerators,the mercaptobenzothiazole(MBT),thiuram,and thiocarbamatetype compounds can be detected and quantified by this method.If the specific rubber accelerator(s)present in the glovematerial is not known,quantification is based on zinc dibutyl-dithiocarbamate(ZDBC)equivalents.This method will notdetect all potential rubber accelerators,including mercaptoben-zothiazole disulfide,dimorpholine,thioureas and diphenyldiamine.1.2 For the purpose of this test method,the range ofchemical accelerator measurement is based on the limit ofdetection(LOD)established in the performing laboratory.1.3 This test method should be performed by experiencedanalysts or under the supervision of those experienced in theuse of spectroscopy and working with organic solvents.1.4 This test method has not been validated for measure-ment of long chain dithiocarbamates or accelerators from otherrubber products,such as lubricated condoms(1).2Althoughthis assay has been reported in the literature for the evaluationof accelerator levels in condoms,further validation for accel-erator measurement from other rubber products is required bythe testing laboratory prior to use.1.5 This test method is not designed to evaluate the potentialof rubber materials to induce or elicit Type IV skin sensitiza-tion reactions(for Type IV skin sensitization reactions see TestMethod D6355).Total extractable accelerator content does notreflect bioavailablity of individual accelerators that are de-tected and measured by this method.This test method shouldbe used to test and measure the total residual chemicalaccelerator level in NRL and nitrile gloves under controlledlaboratory conditions,and should not be used to describe,appraise,or assess the hazard or risk of these materials orproducts under actual in-use conditions.1.6 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.7 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:3D3577 Specification for Rubber Surgical GlovesD3578 Specification for Rubber Examination GlovesD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesD6355 Test Method for Human Repeat Insult Patch Testingof Medical Gloves3.Terminology3.1 Total thiol vulcanization accelerator includes MBT,zincdithiocarbamates(ZDTCs)and thiurams.3.2 Definitions:3.2.1 limit of detection(LOD),nthe lowest acceleratorconcentration that can be measured and be statistically differentfrom the blank.3.2.1.1 DiscussionThe LOD is expressed as 3.3 stan-dard error of the y-intercept of the standard plot regression linedivided by the slope of the calibration line.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.40 on Consumer RubberProducts.Current edition approved Nov.1,2014.Published December 2014.Originallyapproved in 2009.Last previous edition approved in 2009 as D7558 09.DOI:10.1520/D7558-09R14.2The boldface numbers in parentheses refer to a list of references at the end ofthis standard.3For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.2 limit of quantitation(LOQ),nthe lowest acceleratorconcentration that can be measured to produce quantitativelymeaningful results with acceptable precision and accuracy.3.2.2.1 DiscussionThe LOQ is expressed as 10 standarderror of the y-intercept of the standard plot regression linedivided by the slope of the calibration line.3.2.3 linear range,narea of a graph of absorbance versusconcentration that approximates a straight line.3.2.4 spectrophotometric measurement,n the unit of mea-sure of the instrument that is