ASTM_D_5108_-_90_2007.pdf

Designation:D510890(Reapproved 2007)Standard Test Method forOrganotin Release Rates of Antifouling Coating Systems inSea Water1This standard is issued under the fixed designation D5108;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 organotin expressed as tributyltin(TBT)isreleased from an antifouling(AF)coating in synthetic seawater using graphite furnace atomic absorption spectrophotom-etry(GF-AAS).This does not exclude the use of otheranalytical methodology for measurement of organotin in seawater such as gas chromatography.1.2 The values stated in SI units are to be regarded asstandard.The inch-pound units given in parentheses are forinformation only.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 and health practices and determine the applica-bility of regulatory limitations prior to use.For specific hazardstatements,see Section 7.2.Referenced Documents2.1 ASTM Standards:2D1141 Practice for the Preparation of Substitute OceanWaterD1212 Test Methods for Measurement of Wet Film Thick-ness of Organic CoatingsD4138 Practices for Measurement of Dry Film Thickness ofProtective Coating Systems by Destructive,Cross-Sectioning Means3.Summary of Test Method3.1 The candidate paint system is applied to cylindrical testspecimens.The coated specimens are placed in a tank ofsynthetic sea water where the tin levels are kept low bycirculating the sea water through a carbon filter.At specifiedintervals,each specimen is placed in 1500 mL of unused seawater and is rotated for 1 h.The rate of tributyltin release fromthe paint is determined by measuring tributyltin concentrationsin the sea water.3.2 Analysis of sea water for tributyltin is conducted byextracting the organotin with toluene,washing with sodiumhydroxide,and measuring for total tin using(GF-AAS).4.Significance and Use4.1 This test method is designed to provide a laboratoryprocedure to measure changes in the release rates of solventsoluble tin(tributyl-and triphenyltin)that occur during aperiod of immersion under specified conditions of constanttemperature,pH,salinity,and low heavy-metal concentrationsin the surrounding sea water.Quantitative measurement of therelease rate is necessary to help in selection of materials,inproviding quality assurance,and in understanding the perfor-mance mechanism.4.2 This test method serves only as a guide for organotinrelease rates in service.Organotin release rates of antifouling(AF)paint systems in service can vary over the life of thecoating system depending on the formulation and the environ-ment.Differences in berthing locations,operating schedules,length of service,condition of paint-film surface,temperature,pH,and salinity can affect results,Results obtained may notnecessarily reflect actual tributyltin release rates that will occurin service,but provide reliable comparisons of the release ratecharacteristics of different antifouling formulations.4.3 This test method will serve to characterize the earlyrelease rate pattern,as well as estimate the steady state release,of tributyltin from both self-polishing copolymer and free-association antifouling paints.5.Apparatus5.1 Release-Rate Measuring ContainerA 2-L(nominal12gal)polycarbonate container,3approximately 13.5 cm(5.5 in.)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 June 1,2007.Published August 2007.Originallyapproved in 1990.Last previous edition approved in 2002 as D5108-90(2002).DOI:10.1520/D5108-90R07.2For 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.3ANalgene Container,available from Cole-Palmer,7425 N.OakAve.,Chicago,IL 60648,catalog number R-6761-20,or equivalent,has been found satisfactory forthis purpose.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 in diameter and 19 cm(7.5 in.)high,fitted with threepolycarbonate rods approximately 6 mm(nominal14in.)indiameter to serve as baffles.Rods shall be evenly spaced on theinside circumference of the container to prevent swirling ofwater with the test cylinder during rotation.The rods will besecured to the container walls using acetone or methylenechloride.5.2 Constant Temperature BathA temperature controlledwater bath capable of maintaining a