1、Designation: D4610 98 (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
2、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 guide describes techniques used for determiningthe presence of
3、fungal or algal 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 con
4、cerns, 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.2. Referenced Documents2.1 ASTM Standards:2D2022 Test Methods of Sampling and Che
5、mical 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 films. This gui
6、de 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 addition, poor
7、adhesion, staining/bleeding,and many other problems may result. This guide describesmethods for removing fungal or algal growth prior to repaint-ing.NOTE 1It 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
8、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.NOTE 2This procedure is intended for use when recoating the surface.Reports of using
9、 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 p
10、igments (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 he
11、at and sunlight 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 Gr
12、owth onPaint:5.1.1 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
13、furtherconfirmation do 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
14、 with Test Method D3274.1This 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 June 1, 2013. Published June 2013. Originallyapproved in 1
15、986. Last previous edition approved in 2009 as D4610 98 (2009).DOI: 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 Summa
16、ry page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.2.2 SubcultureApply a prepared petri dish containinga raised convex surface of nutrient agar culture medium3directly to the surface to be sampled and exert
17、 moderatepressure. Replace the cover and incubate for at least 72 h at35C (95F). Examine the agar surface visually as in 5.1.2.1.NOTE 3The 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 the surface with a so
18、lution of approximately 2 %phosphate-free detergent in water.NOTE 4The term wash as it is used in 5.2.1 and 5.2.3 is defined asfirmly scrubbing the surface with a fully wet sponge or other suitableapplicator. Care should be taken to ensure the surface is thoroughly wetwith cleaning solution.5.2.2 Th
19、oroughly rinse the surface with water to removeresidual detergent.5.2.3 Wash the surface with a solution of 1 part by volumeof sodium hypochlorite 5 % aqueous solution and 3 parts byvolume of water.NOTE 5See warnings in Note 1 and Note 2. Also be warned thatoverspray of bleach can be detrimental to
20、ornamental shrubs, plants orlawn, and can “bleach,” discolor, or otherwise degrade adjacent areas ifnot adequately protected from exposure. Adequate personal protectiveequipment should always be used.NOTE 6The solution should be allowed to remain on the surface from10 to 15 min.NOTE 7The sodium hypo
21、chlorite solution and the 2 % detergentsolution may be combined 1:1 by volume in one treatment if desired.5.2.4 Thoroughly rinse the surface with water to removeresidual sodium hypochlorite (see Note 1).5.2.5 If agreed upon by the parties involved, reinspect thesurface in accordance with 5.1 to ensu
22、re that there has beenadequate removal. Refer to the coating manufacturers litera-ture for recommended drying time before recoating.6. Keywords6.1 algals; bleaches; fungals; microbials; washesASTM International takes no position respecting the validity of any patent rights asserted in connection wit
23、h any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible techn
24、ical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful considerati
25、on at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Har
26、bor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).3Agar available from various microbiological supply companies.D4610 98 (2013)2
