1、Designation:D257406(Reapproved 2012)Standard Test Method forResistance of Emulsion Paints in the Container to Attack byMicroorganisms1This standard is issued under the fixed designation D2574;the number immediately following the designation indicates the year oforiginal adoption or,in the case of re
2、vision,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.Scope*1.1 This test method covers the determination of the relativeresistance of emulsion paints to attack in the
3、 container bymicroorganisms.1.2 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.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 s
4、tandard 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:2D5588 Test Method for Determination of the MicrobialCondition of Paint,Paint Raw Materials,and Plant Areas3.Summary of Test
5、Method3.1 This test method is designed to challenge samples of oneor more paints containing various levels of one or morebiocides with a known amount of bacteria and rate the abilityof the test paint(s)to control the“contamination.”4.Significance and Use4.1 Spoilage of paint in the container can res
6、ult in putrefac-tion,lowered pH,gas formation,and decrease in viscosity.Thistest method provides a standard procedure for the evaluation ofthe resistance of emulsion paints to microbial deterioration.The results should enable:(1)the paint manufacturer to selectan effective preservative and(2)the sup
7、plier of preservatives toevaluate the performance in emulsion paints of competitive anddevelopmental preservatives.4.2 This test method should be used preferably by personswho have had basic microbiological training.NOTE1The reliability of the results obtained from this test method isextremely depen
8、dent on the techniques employed.Improper techniquescan result in a sterile sample appearing to be contaminated,and evenworse,a contaminated sample appearing to be sterile(see also Note 2).Itis recommended that you consult with your biocide supplier,raw materialsupplier,or an independent testing labo
9、ratory to confirm questionableresults.Formulation and raw materials quality may also vary and therebyaffect the test results.5.Apparatus and Materials5.1 Balance,capable of weighing to 0.10 g.5.2 Incubator,or other device capable of maintaining aconstant temperature between 28 and 32C.5.3 Refrigerat
10、or,maintained at 10 to 13C.5.4 Screwcap Borosilicate Test Tubes,125 by 15-mm.5.5 Borosilicate Flasks,1-L.5.6 Screwcap Bottles,150-mL.5.7 Autoclave,capable of producing 103 kPa(15 psi)ofsteam pressure at 121C and maintaining it for a minimum of15 min.An autoclave is not necessary if prepared agar sla
11、ntsare used.5.8 Pipettes or an Automatic Pipettor,sterile,1-mL,withsterile disposable pipette tips for 1 mL.5.9 Petri Dishes,sterile.5.10 Dehydrated Tryptic Soy Agar(TSA),medium,or pre-prepared slants,plates,and broth tubes.35.11 Swabs,sterile cotton.1This test method is under the jurisdiction of AS
12、TM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.28 on Biodeterioration.Current edition approved June 1,2012.Published July 2012.Originally approvedin 1967.Last previous edition approved in 2006 as D2574 06.DOI:10.1520/D2574
13、-06R12.2For 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.3Available from microbiological supply companies.Media with
14、 TTC indicatordye may be used.In general,the TTC helps visualize contamination,but it has beenreported on occasion to inhibit the growth of some bacteria.Interferences frompigments in materials being tested may make the color change difficult to see.Ifself-prepared plates are used with the TTC indic
15、ator,0.01%TTC indicator shouldbe used and it must be added after autoclaving.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.12 Laminar Flow Hood,Sterile Room,or at Least
16、aLaboratory Testing Area,relatively clean,free of blowing dustand dirt,etc.,which can be used for streaking plates.5.13 Antiseptic Solution,to help maintain sterility of testingarea surfaces(4.12)(for example,70%ethanol solution).5.14 A minimum of 235 mL(12pt)of each paint sampleunder test(pre-loaded with biocide).5.15 Aminimum of 475 mL(1 pt)of paint identical to 5.14,but containing no biocide.5.16 Twenty-four Hour Cultures of a Pseudomonas sp.(forexample,Pseudomonas aeruginosa ATCC#10145)and a