ASTM_D_6903_-_07_2020.pdf

Designation:D690307(Reapproved 2020)Standard Test Method forDetermination of Organic Biocide Release Rate FromAntifouling Coatings in Substitute Ocean Water1This standard is issued under the fixed designation D6903;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 the laboratory determination ofthe rate at which organic biocide is released from an antifoul-ing coating exposed in substitute ocean water.The test is runentirely in the laboratory under controlled conditions of pH,temperature,salinity,and hydrodynamics.Analytical proce-dures are provided for the determination of the release rate of4,5-dichloro-2-n-octylisothiazolin-3-one(DCOIT),zinc andcopper pyrithione(ZPT and CuPT),and N-cyclopropyl-N-(1,1-dimethylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine(CDMTD).At predetermined intervals,substitute ocean watersamples are analyzed for leached biocide using a suitableanalytical technique.1.2 In cases in which the antifouling coating contains bothan organic biocide and a copper-based biocide,the release rateof copper may optionally be concurrently determined accord-ing to the procedure found in Test Method D6442.1.3 The procedure contains the preparation steps for thedetermination of the release rate of biocide in substitute oceanwater from antifouling paints including apparatus,reagents,holding tank conditions,and sampling point details.Theprocedure calls for the accurate determination of organicbiocide concentrations in substitute ocean water at the low gL-1(parts per billion,ppb)level.To detect and correct forreagent impurities and allow a suitable level of analyticalprecision to be achieved,the analytical method to be used forthe determination of the concentration of organic biocide insubstitute ocean water must meet the acceptability criteriagiven in Annex A2.Where Annex A2 specifies a limit ofquantitation(LOQ),the procedure for determining the LOQ forthe organic biocide in substitute ocean water by the analyticalmethod presented in Annex A3 is to be followed.1.4 Suitable analytical methods that use high-performanceliquid chromatography(HPLC)for determining the concentra-tion of DCOIT,ZPT and CuPT,and CDMTD in substituteocean water are given in Appendix X1 Appendix X3,respectively.Other methods may be used provided that theymeet the appropriate criteria given in Annex A2.1.5 When the release rate of a highly photosensitive organicbiocide is being determined,steps must be taken to protect theapparatus and samples from exposure to natural and artificialvisible light sources.Any such requirement for these steps tobe taken for a particular biocide is indicated in Annex A2.1.6 The practical limits for quantifying biocide release ratesby this method are from 4.5 to 500 g cm-2d-1for DCOIT,0.36to 500 g cm-2d-1for CuPT,0.36 to 500 g cm-2d-1for ZPT,and 2.7 to 500 g cm-2d-1for CDMTD.These ranges may beextended to 3.8 to 500 g cm-2d-1for DCOIT,0.16 to 500 gcm-2d-1for CuPT,0.2 to 500 g cm-2d-1for ZPT,and 2.2 to500 g cm-2d-1for CDMTD if the procedures described inAppendix X1 Appendix X3(as appropriate)are followed.The quantitation of release rates lower than these ranges willrequire the use of analytical methods with lower limits ofquantitation than those specified in Annex A2.1.7 The results of this test method do not reflect environ-mental biocide release rates for antifouling products,and arenot suitable for direct use in the process of generatingenvironmental risk assessments,environmental loadingestimates,or for establishing release rate limits for regulatorypurposes.See also Section 4.1.8 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.9 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.1.10 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.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.45 on Marine Coatings.Current edition approved Aug.1,2020.Published August 2020.Originallyapproved in 2007.Last previous edition approved in 2013 as D6903 07(2013).DOI:10.1520/D6903-07R20.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Co