1、Designation: D 3274 09Standard Test Method forEvaluating Degree of Surface Disfigurement of Paint Filmsby Fungal or Algal Growth, or Soil and Dirt Accumulation1This standard is issued under the fixed designation D 3274; the number immediately following the designation indicates the year oforiginal a
2、doption 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.This standard has been approved for use by agencies of the Department of Defense.
3、1. Scope*1.1 Fungal growth, frequently referred to as mildew in thepaint industry, causes defacement of paint film exposed out-doors. The visual rating of paint surface disfigurement due tofungal or algal attack is required in order to compare theperformance of different coatings.1.2 This method of
4、rating mildew evaluation is intended tobe used on exterior exposed paint films. This method may beused to rate interior fungal or algal growth, but it should benoted that the growth patterns on interior surfaces are differentthan exterior due to the lack of weathering influences. It isprimarily inte
5、nded for test specimens, but can also be sued forrating mildew growth on larger structures such as entirehouses. If this is used for large areas, the project should bebroken down into smaller sections.1.3 This method is intended for field use for the macrorating of surface disfigurement only. The vi
6、sual scales aremeant to be used by the unaided eye to rate algal, fungal, or dirtdisfigurement on larger surface areas such as test panels, sidingboards, or entire buildings. Techniques are included for thedifferentiation of soil and dirt.1.4 Fungi will grow on most paint films exposed outdoorsthat
7、are located in conditions favorable to growth. Test proce-dures such as Practices D 1006, D 3456, and G7are availabledescribing natural exposure tests that can be used to exposepaint films, in order to create fungal or algal growth.1.5 The pictorial references available for use with this testmethod
8、provide a numerical basis for rating the degree offungal or algal growth on paint films.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices
9、 and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1006 Practice for Conducting Exterior Exposure Tests ofPaints on WoodD 3456 Practice for Determining by Exterior ExposureTests the Susceptibility of Paint Films to MicrobiologicalAtt
10、ackD 4610 Guide for Determining the Presence of and Remov-ing Microbial (Fungal or Algal) Growth on Paint andRelated CoatingsG7 Practice for Atmospheric Environmental ExposureTesting of Nonmetallic Materials3. Terminology3.1 Types of Fungal GrowthDuring examination of apaint film, it may be possible
11、 to distinguish between the severaltypes of fungal or algal growth. If required, it may be necessaryto note the type of fungal or algal growth found. Undermagnification, and with some identification training, it ispossible to be able to distinguish growth types. The followingdefinitions are some gro
12、wth types that may be found.3.2 hyphae, nthread-like, tubular fungal filaments thatcompose the mycelium.3.3 mildew, na popular term for the conglomerations offungi that grow on and disfigure paint films.3.4 mycelium, nvegetative mass of hyphae forming thebody of a fungus.3.5 sporean asexual reproduc
13、tive cell capable of devel-oping into a mature fungus without fusion with another cell.3.5.1 DiscussionSpores tend to be spherical in morphol-ogy and are observed singly or in clusters. Spores may or maynot be associated with fungal mycelia and can range in a widevariety of colors. Although primaril
14、y gray or black, somespores are green in color and have been mistaken as terrestrialalgae.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.28 on Biodeterioration.Current edi
15、tion approved March 1, 2009. Published May 2009. Originallyapproved in 1973. Last previous edition approved in 2002 as D 3274 95 (2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in
16、formation, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. Significance and Use4.1 The growth of fun
17、gi in and on the surface of paint filmsrepresents a major cause of discoloration or disfigurement ofpainted surfaces. Because of their dark pigmentation, it isfrequently difficult to distinguish fungi from dirt or soilparticles.4.2 Use of Pictorial Standards:4.2.1 The pictorial references that are p
18、art of this testmethod are for illustration purposes and may be used for visualcomparisons.4.2.2 The diagrams represent an idealized schematic ofvarious growth levels on paint films. they are intended as arepresentation only, but will serve as a useful guideline toestablish amount and type of growth
19、.4.2.3 The diagrams represented in Fig. 1 are not derivedfrom a linear scale. The scale is intended to provide for morediscrimination at the earlier stages of fungal or algal growth. Itis at these levels that greater discernment is necessary.4.2.4 Comparisons made on dark colored substrates will bem
20、uch more difficult, and will therefore require much more careand attention. It must be noted that because it is difficult todistinguish mild fungal or algal growth on the very darksubstrates, there may be a tendency to under-rate thosespecimens.5. Soil or Dirt Particles5.1 Fungal or algal ratings ca
21、n be made more difficult by thepresence of dirt and soil particles. The distinction between dirtaccumulation and surface mildew is sometimes difficult todistinguish to the naked eye.5.2 Use visual evaluation under high power binocular mag-nification to assist in determining whether the particle is s
22、oil,dirt, or mildew.NOTE 1After experience has been gained in a certain geographiclocation, recognition of mildew becomes easier and can often be achievedwithout the aid of magnification.5.3 In some cases it is necessary to to place a drop of 5 %sodium hypochlorite (common household bleach) on the p
23、aintsurface to determine if the defacement is biological in accor-dance with Guide D 4610.5.3.1 The bleach will remove the coloration from any livingorganic matter, therefore if the color of the “particles” underthe bleach drop do not change color, that object is probablyeither dirt or soil.5.4 The
24、addition of a drop of bleach is an invasive anddestructive test. The future growth of organisms on that spotand in the immediate surrounding area will be inhibited for along time after the addition. Do not use bleach unless abso-lutely necessary, and make a note on the report form if used.(a)FIG. 1
25、Early Stages of Fungal GrowthD32740926. Visual Evaluations6.1 Whenever fungal or algal growth is being rated visuallyit should be done without the aid of magnification. The ratingshould be made as it appears to the naked eye. Up to 103magnification can be used to assist in the identification ofmilde
26、w and to clarify the rating. Magnification will also help todistinguish between dirt attachment and mildew growth. Ifmagnification is used, it should be noted on the report.6.2 View the paint film under good illumination conditions,either in a controlled light booth under daylight light source, orou
27、tside in the shade. Occasionally it may be necessary to viewthe paint film under strong sunlight.6.3 Rate the specimen using one of the following methods.Under most field use conditions, comparison to the drawingsprovides a satisfactory numerical rating. Use a transparent gridscale to determine perc
28、ent area coverage for more accurateratings as described in 6.3.3.6.3.1 There are three different growth patterns described inthis standard:Description DesignationSpot Growth SNon Uniform Spread PComplete Coverage G6.3.2 Determine which growth pattern most closely matchesthat seen on the specimen. Se
29、e Fig. 1 a through c, for visualrepresentation of these patterns.6.3.3 Compare the growth to the drawings. Estimate whichpictorial reference most closely matches the actual test speci-men being evaluated. Rate the number and type of growthpattern. Derive the numerical rating directly from the rating
30、scales shown in Table 1. Include the growth pattern type asdetermined from Fig. 1 a through c. Actual photographs offungal or algal surface growth are shown in Fig. 2.6.4 Rating ScalesRate the mildew growth using either anestimate of the percentage of the surface covered, or byapplying a descriptive
31、 term to the general appearance. Thecross-reference of these three items is detailed in Table 1.6.4.1 The odd numbered ratings not shown in Table 1 maybe applied by interpolation. Odd numbered ratings are shownin Fig. 1 a through c. No pictures for 10 or zero ratings areshown in the figures.6.5 When
32、 the growth is found to be concentrated in one areaof the test surface, enter a note in the report to this effect. Statewhere the concentration was found, and what type of growthwas most prevalent.(b)FIG. 1 Early Stages of Fungal Growth (continued)D32740936.6 Ignore the area around the outer edge of
33、 the test surfaceif the mildew growth extends all the way to the edge. Themildew growth here may be due to other influences andtherefore not necessarily reflect the true resistance of the paintfilm. If there is growth occurring along one edge that hasinvaded other areas on the surface, originating t
34、ypically at thebottom, report this as a special note.6.7 If there are two growth types, for example, Spot andNon-Uniform, report the coverage and type for both types. It ispossible that the type of coverage might change during thecourse of the exposure, typically from Spot to Non-Uniform orComplete
35、Coverage.6.8 IdentificationIf the fungal or algal species is known,indicate on the report the name of the organism and the methodby which the identification was made.7. Report7.1 The report should include the numerical rating value,plus any notes regarding uniformity or other morphology.7.2 Use a re
36、port format as agree upon between the contrac-tual parties. As a minimum, report the following criteria. Notethat all the following information may not be available if theexposure is carried out by an independent testing agency.7.2.1 Unique reference number to identify test series.7.2.2 Paint panel
37、identification.7.2.3 Date of report.7.2.4 Date of exposure.7.2.5 Location of exposure.7.2.6 Numerical fungus rating.7.2.7 Any notes about morphology or uniformity.8. Precision and Bias38.1 The precision of this test method has been tested bysubcommittee D01.28 by means of round robin testing. Re-pea
38、tability of evaluations by the same inspector has beenshown to improve when using the pictorial references evenwith little or no training. Overall variability between users ofthis standard is 62.4 rating points without training and 61.63Supporting data pending being filed at ASTM International Headq
39、uarters.(c)FIG. 1 Early Stages of Fungal Growth (continued)TABLE 1 Rating ScalesRating Coverage % Description10 0 No Fungal Growth9 0.03 Trace8 0.1 Slight6 1 Moderate4 10 Pronounced2 33 Severe0 50 Complete CoverageD3274094Slight MildewFIG. 2 Examples of Paint Disfigurement through Fungal or Algal Gr
40、owthD3274095Moderate MildewFIG. 2 Examples of Paint Disfigurement through Fungal or Algal Growth (continued)D3274096Severe MildewFIG. 2 Examples of Paint Disfigurement through Fungal or Algal Growth (continued)D3274097points with training. When removing high and low values andcorrecting for individu
41、al biases, the overall variability can bereduced to 61.1 rating points. This was measured using 12individuals, rating 20 specimens, at 2 different time periods.8.1.1 The use of this rating method to rank specimens isextremely reliable and repeatable. The ranking of the speci-mens by these individual
42、s was repeatable at R = 0.99 using theSpearman Rank Coefficient to compare the ranking at each ofthe two rating times.8.2 Bias cannot be determined due to the lack of a standardreference to be used for comparison. This is a highly subjectivemethod of evaluation, but some individual biases can bedete
43、rmined by frequent intercomparisons amongst groups ofraters.9. Keywords9.1 disfigurement; fungus; mildew; pictorial standardsSUMMARY OF CHANGESCommittee D01 has identified the location of selected changes to this standard since the last issue(D 3274 - 95 (2002) that may impact the use of this standa
44、rd. (Approved March 1, 2009.)(1) Replace old photographs of fungal or algal growth withthree sets of drawings depicting scales for visually ratingfungal or algal growth.(2) Added descriptions of growth types and added a table ofreport values.(3) Added three digital photographs of mildew growth on ap
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47、itional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration 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 t
48、he ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor 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).D3274098
