ASTM D4610-98(2021)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D4610 − 98 (Reapproved 2021)
Standard Guide for
Determining the Presence of and Removing Microbial
(Fungal or Algal) Growth on Paint and Related Coatings
This standard is issued under the fixed designation D4610; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 3.2 Repainting a surface contaminated with fungi or algae
generally causes more rapid infestation of the new paint than
1.1 This guide describes techniques used for determining
repainting a surface from which fungal or algal growth has
the presence of fungal or algal growth on paint and related
been removed. In addition, poor adhesion, staining/bleeding,
coatings and methods for removal of such growth prior to
and many other problems may result. This guide describes
recoating.
methods for removing fungal or algal growth prior to repaint-
1.2 The values stated in SI units are to be regarded as the
ing.
standard. The values given in parentheses are for information
NOTE 1—It is extremely important that all steps and notes be read and
only.
followed. In particular the washing steps outlined in 5.2.2 and 5.2.4 must
1.3 This standard does not purport to address all of the befullycarriedout,sinceresidualsodiumhypochlorite(bleach)cancause
many of the same problems, or even loss of coloration after repainting,
safety concerns, if any, associated with its use. It is the
and residual phosphate detergents can encourage further fungal and algal
responsibility of the user of this standard to establish appro-
growth.
priate safety, health, and environmental practices and deter-
NOTE2—Thisprocedureisintendedforusewhenrecoatingthesurface.
mine the applicability of regulatory limitations prior to use.
Reports of using this procedure to remove fungi and algae without
1.4 This international standard was developed in accor- recoating necessitate inclusion of a warning about the adverse effects of
bleach on a coating film. The oxidative effects of bleach can degrade film
dance with internationally recognized principles on standard-
properties, including particularly the “bleaching” (loss of color) in films
ization established in the Decision on Principles for the
containingorganiccoloringpigments(suchasquinacridones,etc.),lossof
Development of International Standards, Guides and Recom-
gloss, chalking, etc. A small patch must be tested prior to use of this
mendations issued by the World Trade Organization Technical
procedure for that purpose.
Barriers to Trade (TBT) Committee.
4. Reagents
2. Referenced Documents
4.1 Sodium Hypochlorite, approximately 5 % aqueous
(NaOCl) as commercial household bleach. Because sodium
2.1 ASTM Standards:
hypochlorite decomposes on exposure to heat and sunlight and
D2022Test Methods of Sampling and ChemicalAnalysis of
becomesineffective,useonlyfreshmaterial.SeeTestMethods
Chlorine-Containing Bleaches
D3274Test Method for Evaluating Degree of Surface Dis- D2022 for methods of sampling and chemical analysis.
figurement of Paint Films by Fungal or Algal Growth, or
4.2 Phosphate-Free, non-ammonia-containing detergent or
Soil and Dirt Accumulation
commercial cleaner recommended for washing paint.
3. Significance and Use
5. Procedures
3.1 Microbial growth is a major cause of discoloration and
5.1 DeterminingthePresenceofFungalorAlgalGrowthon
deterioration of paint films. This guide describes techniques
Paint:
used to distinguish fungi and algae from other surface con-
5.1.1 Chemical—Apply a drop of 5% aqueous sodium
taminants.
hypochlorite solution (common household bleach) to the area
suspected of being contaminated with fungal or algal growth.
This guide is under the jurisdiction of ASTM Committee D01 on Paint and
Fungal or algal discoloration will normally bleach within 60 s.
Related Coatings, Materials, and Applications and is the direct responsibility of
Discoloration that does not bleach is probably dirt. For further
Subcommittee D01.28
...