ASTM D4610-98

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D 4610 – 98
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.
and residual phosphate detergents can encourage further fungal and algal
1. Scope
growth.
1.1 This guide describes techniques used for determining
NOTE 2—This procedure is intended for use when recoating the surface.
the presence of fungal or algal growth on paint and related
Reports of using this procedure to remove fungi and algae without
coatings and methods for removal of such growth prior to
recoating necessitate inclusion of a warning about the adverse effects of
recoating. bleach on a coating film. The oxidative effects of bleach can degrade film
properties, including particularly the “bleaching” (loss of color) in films
1.2 This standard does not purport to address all of the
containing organic coloring pigments (such as quinacridones, etc.), loss of
safety concerns, if any, associated with its use. It is the
gloss, chalking, etc. A small patch must be tested prior to use of this
responsibility of the user of this standard to establish appro-
procedure for that purpose.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
4. Reagents
4.1 Sodium Hypochlorite, approximately 5 % aqueous
2. Referenced Documents
(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 Determining the Presence of Fungal or Algal Growth on
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
NOTE 1—It is extremely important that all steps and notes be read and disfigurement in accordance with Test Method D 3274.
followed.
...