ASTM D4610-98(2004)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D4610–98(Reapproved2004)
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 D 4610; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
NOTE 1—It is extremely important that all steps and notes be read and
1. Scope
followed. In particular the washing steps outlined in 5.2.2 and 5.2.4 must
1.1 This guide describes techniques used for determining
be fully carried out, since residual sodium hypochlorite (bleach) can cause
the presence of fungal or algal growth on paint and related
many of the same problems, or even loss of coloration after repainting,
coatings and methods for removal of such growth prior to
and residual phosphate detergents can encourage further fungal and algal
recoating. growth.
NOTE 2—Thisprocedureisintendedforusewhenrecoatingthesurface.
1.2 The values stated in SI units are to be regarded as the
Reports of using this procedure to remove fungi and algae without
standard. The values given in parentheses are for information
recoating necessitate inclusion of a warning about the adverse effects of
only.
bleach on a coating film. The oxidative effects of bleach can degrade film
1.3 This standard does not purport to address all of the
properties, including particularly the “bleaching” (loss of color) in films
safety concerns, if any, associated with its use. It is the
containing organic coloring pigments (such as quinacridones, etc.), loss of
responsibility of the user of this standard to establish appro-
gloss, chalking, etc. A small patch must be tested prior to use of this
priate safety and health practices and determine the applica- procedure for that purpose.
bility of regulatory limitations prior to use.
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
D 2022 Test Methods of Sampling and Chemical Analysis
becomes ineffective, use only fresh material. See Test Methods
of Chlorine-Containing Bleaches
D 2022 for methods of sampling and chemical analysis.
D 3274 Test Method for Evaluating Degree of Surface
4.2 Phosphate-Free, non-ammonia-containing detergent or
Disfigurement of Paint Films by Microbial (Fungal or
commercial cleaner recommended for washing paint.
Algal) Growth or Soil and Dirt Accumulation
5. Procedures
3. Significance and Use
5.1 DeterminingthePresenceofFungalorAlgalGrowthon
3.1 Microbial growth is a major cause of discoloration and
Paint:
deterioration of paint films. This guide describes techniques
5.1.1 Chemical—Apply a drop of 5 % aqueous sodium
used to distinguish fungi and algae from other surface con-
hypochlorite solution (common household bleach) to the area
taminants.
suspected of being contaminated with fungal or algal growth.
3.2 Repainting a surface contaminated with fungi or algae
Fungal or algal discoloration will normally bleach within 60 s.
generally causes more rapid infestation of the new paint than
Discoloration that does not bleach is probably dirt. For further
repainting a surface from which fungal or algal growth has
confirmation do visual and subculture tests.
been removed. In addition, poor adhesion, staining/bleeding,
5.1.2 The following procedures should preferably be used
and many other problems may result. This guide describes
by persons who have had basic microbiological training:
methods for removing fungal or algal growth prior to repaint-
5.1.2.1 Visual—Examine the surface using magnification
ing.
from 10 to 1003 to distinguish among fungal, algal, or dirt
disfigurement in accor
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