1、Designation:D461098(Reapproved 2013)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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D2022 Test Methods of Sampling and Chemical Analysis of
5、Chlorine-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 films.This guide describes techniq
6、uesused 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 addition,poor adhesion,staining/blee
7、ding,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 mustbe fully carried out,since residual
8、 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 using this procedure to remove fungi
9、 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 pigments(such as quinacridones,etc.),
10、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 sunlight andbecomes ineffective,use only
11、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 ChemicalApply a drop of 5%aqueous
12、 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 visual and subculture tests.5.1.2
13、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 D3274.1This guide is under the jurisdicti
14、on of ASTM Committee D01 on Paint andRelated Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.28 on Biodeterioration.Current edition approved June 1,2013.Published June 2013.Originallyapproved in 1986.Last previous edition approved in 2009 as D4610 98(2009).DOI
15、:10.1520/D4610-98R13.2For 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
16、Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.1.2.2 SubcultureApply a prepared petri dish containinga raised convex surface of nutrient agar culture medium3directly to the surface to be sampled and exert moderatepressure.Replace the cover and incubate for at least 72 h at35C(95F).Examine the agar surface visually as in 5.1.2.1.NOTE3The culture medium must contain the nutrients necessary forgrowth of algae and fungi.5.2 Removal of Fungal and Algal Growth on Paint:5.2.1 Wash t