1、Designation:D461098(Reapproved 2021)Standard Guide forDetermining the Presence of and Removing Microbial(Fungal or Algal)Growth on Paint and Related Coatings1This standard is issued under the fixed designation D4610;the number immediately following the designation indicates the year oforiginal adopt
2、ion 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 guide describes techniques used for determiningthe presence of fungal or al
3、gal growth on paint and relatedcoatings and methods for removal of such growth prior torecoating.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,
4、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 r
5、ecognized 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.Referenced Documents2.1 ASTM Standards:2D2022 Test Methods of
6、 Sampling and Chemical Analysis ofChlorine-Containing BleachesD3274 Test Method for Evaluating Degree of Surface Dis-figurement of Paint Films by Fungal or Algal Growth,orSoil and Dirt Accumulation3.Significance and Use3.1 Microbial growth is a major cause of discoloration anddeterioration of paint
7、films.This guide describes techniquesused to distinguish fungi and algae from other surface con-taminants.3.2 Repainting a surface contaminated with fungi or algaegenerally causes more rapid infestation of the new paint thanrepainting a surface from which fungal or algal growth hasbeen removed.In ad
8、dition,poor adhesion,staining/bleeding,and many other problems may result.This guide describesmethods for removing fungal or algal growth prior to repaint-ing.NOTE1It is extremely important that all steps and notes be read andfollowed.In particular the washing steps outlined in 5.2.2 and 5.2.4 mustb
9、e fully carried out,since residual sodium hypochlorite(bleach)can causemany of the same problems,or even loss of coloration after repainting,and residual phosphate detergents can encourage further fungal and algalgrowth.NOTE2This procedure is intended for use when recoating the surface.Reports of us
10、ing this procedure to remove fungi and algae withoutrecoating necessitate inclusion of a warning about the adverse effects ofbleach on a coating film.The oxidative effects of bleach can degrade filmproperties,including particularly the“bleaching”(loss of color)in filmscontaining organic coloring pig
11、ments(such as quinacridones,etc.),loss ofgloss,chalking,etc.A small patch must be tested prior to use of thisprocedure for that purpose.4.Reagents4.1 Sodium Hypochlorite,approximately 5%aqueous(NaOCl)as commercial household bleach.Because sodiumhypochlorite decomposes on exposure to heat and sunligh
12、t andbecomes ineffective,use only fresh material.See Test MethodsD2022 for methods of sampling and chemical analysis.4.2 Phosphate-Free,non-ammonia-containing detergent orcommercial cleaner recommended for washing paint.5.Procedures5.1 Determining the Presence of Fungal or Algal Growth onPaint:5.1.1
13、 ChemicalApply a drop of 5%aqueous sodiumhypochlorite solution(common household bleach)to the areasuspected of being contaminated with fungal or algal growth.Fungal or algal discoloration will normally bleach within 60 s.Discoloration that does not bleach is probably dirt.For furtherconfirmation do
14、visual and subculture tests.5.1.2 The following procedures should preferably be usedby persons who have had basic microbiological training:5.1.2.1 VisualExamine the surface using magnificationfrom 10 to 100 to distinguish among fungal,algal,or dirtdisfigurement in accordance with Test Method D3274.1
15、This guide is under the jurisdiction of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.28 on Biodeterioration.Current edition approved Nov.1,2021.Published November 2021.Originallyapproved in 1986.Last previous edition a
16、pproved in 2017 as D4610 98(2017).DOI:10.1520/D4610-98R21.2For 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.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 o
