ASTM G21-09
(Specification)Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi
Standard Practice for Determining Resistance of Synthetic Polymeric Materials to Fungi
SIGNIFICANCE AND USE
The synthetic polymer portion of these materials is usually fungus-resistant in that it does not serve as a carbon source for the growth of fungi. It is generally the other components, such as plasticizers, cellulosics, lubricants, stabilizers, and colorants, that are responsible for fungus attack on plastic materials. To asses materials other than plastics, use of this test method should be agreed upon by all parties involved. It is important to establish the resistance to microbial attack under conditions favorable for such attack, namely, a temperature of 2 to 38°C (35 to 100°F) and a relative humidity of 60 to 100 %.
The effects to be expected are as follows:
Surface attack, discoloration, loss of transmission (optical), and
Removal of susceptible plasticizers, modifiers, and lubricants, resulting in increased modulus (stiffness), changes in weight, dimensions, and other physical properties, and deterioration of electrical properties such as insulation resistance, dielectric constant, power factor, and dielectric strength.
Often the changes in electrical properties are due principally to surface growth and its associated moisture and to pH changes caused by excreted metabolic products. Other effects include preferential growths caused by nonuniform dispersion of plasticizers, lubricants, and other processing additives. Attack on these materials often leaves ionized conducting paths. Pronounced physical changes are observed on products in film form or as coatings, where the ratio of surface to volume is high, and where nutrient materials such as plasticizers and lubricants continue to diffuse to the surface as they are utilized by the organisms.
Since attack by organisms involves a large element of chance due to local accelerations and inhibitions, the order of reproducibility may be rather low. To ensure that estimates of behavior are not too optimistic, the greatest observed degree of deterioration should be reported.
Conditioning of the specimens, ...
SCOPE
1.1 This practice covers determination of the effect of fungi on the properties of synthetic polymeric materials in the form of molded and fabricated articles, tubes, rods, sheets, and film materials. Changes in optical, mechanical, and electrical properties may be determined by the applicable ASTM methods.
1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
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Designation: G21 − 09
StandardPractice for
Determining Resistance of Synthetic Polymeric Materials to
1
Fungi
ThisstandardisissuedunderthefixeddesignationG21;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber 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.
1. Scope D747 Test Method for Apparent Bending Modulus of Plas-
tics by Means of a Cantilever Beam
1.1 This practice covers determination of the effect of fungi
D785 Test Method for Rockwell Hardness of Plastics and
on the properties of synthetic polymeric materials in the form
Electrical Insulating Materials
of molded and fabricated articles, tubes, rods, sheets, and film
D882 Test Method for Tensile Properties of Thin Plastic
materials. Changes in optical, mechanical, and electrical prop-
Sheeting
erties may be determined by the applicable ASTM methods.
D1003 Test Method for Haze and Luminous Transmittance
1.2 The values stated in SI units are to be regarded as the
of Transparent Plastics
standard. The inch-pound units given in parentheses are for
D1708 Test Method forTensile Properties of Plastics by Use
information only.
of Microtensile Specimens
1.3 This standard does not purport to address all of the
E96/E96M Test Methods for Water Vapor Transmission of
safety concerns, if any, associated with its use. It is the Materials
responsibility of the user of this standard to establish appro-
E308 PracticeforComputingtheColorsofObjectsbyUsing
priate safety and health practices and determine the applica- the CIE System
bility of regulatory limitations prior to use.
2.2 TAPPI Standard:
4
Test Method T 451-CM-484 Flexural Properties of Paper
2. Referenced Documents
2.3 Federal Standards:
2
2.1 ASTM Standards:
FED STD 191 Method 5204 Stiffness of Cloth, Directional;
D149 Test Method for Dielectric Breakdown Voltage and
5
Self Weighted Cantilever Method
DielectricStrengthofSolidElectricalInsulatingMaterials
FED STD 191 Method 5206 Stiffness of Cloth Drape and
at Commercial Power Frequencies
5
Flex; Cantilever Bending Method
D150 Test Methods forAC Loss Characteristics and Permit-
tivity (Dielectric Constant) of Solid Electrical Insulation
3. Summary of Practice
D257 Test Methods for DC Resistance or Conductance of
Insulating Materials 3.1 The procedure described in this practice consists of
selection of suitable specimens for determination of pertinent
D495 Test Method for High-Voltage, Low-Current, DryArc
Resistance of Solid Electrical Insulation (Withdrawn properties, inoculation of the specimens with suitable
3
organisms, exposure of inoculated specimens under conditions
2013)
D618 Practice for Conditioning Plastics for Testing favorable to growth, examination and rating for visual growth,
and removal of the specimens and observations for testing,
D638 Test Method for Tensile Properties of Plastics
either before cleaning or after cleaning and reconditioning.
NOTE 1—Since the procedure involves handling and working with
1
This practice is under the jurisdiction ofASTM Committee G03 on Weathering
fungi, it is recommended that personnel trained in microbiology perform
and Durability and is the direct responsibility of Subcommittee G03.04 on
the portion of the procedure involving handling of organisms and
Biological Deterioration.
inoculated specimens.
Current edition approved Dec. 1, 2009. Published March 2010. Originally
approvedin1961.Lastpreviouseditionapprovedin2002asG21 – 96 (2002).DOI:
10.1520/G0021-09.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
4
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from TechnicalAssociation of the Pulp and Paper Industry (TAPPI),
Standards volume information, refer to the standard’s Document Summary page on 15 Technology Parkway South, Norcross, GA 30092, http://www.tappi.org.
5
the ASTM website. Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
3
The last approved version of this historical standard is referenced on Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http://
www.astm.org. dodssp.daps.dla.mil.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
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G21−09
4. Significance and Use 5.2 Incubator—Incubating equipment for all test methods
shall maintain a temperature of 28 to 30°C (82.4 to 86°F) and
4.1 The synthetic polymer portion of these materials is
a relative humidity not less than 85 %.Automatic recording of
usually fungus-resistant in that it does not serve as a carbon
wet
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:G21–96 (Reapproved 2002) Designation:G21–09
Standard Practice for
Determining Resistance of Synthetic Polymeric Materials to
1
Fungi
ThisstandardisissuedunderthefixeddesignationG21;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoption or, in the case of revision, the year of last revision.Anumber 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.
1. Scope
1.1 This practice covers determination of the effect of fungi on the properties of synthetic polymeric materials in the form of
moldedandfabricatedarticles,tubes,rods,sheets,andfilmmaterials.Changesinoptical,mechanical,andelectricalpropertiesmay
be determined by the applicable ASTM methods.
1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for
information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at
Commercial Power Frequencies
D150 Test Methods for AC Loss Characteristics and Permittivity (Dielectric Constant) of Solid Electrical Insulation
D257 Test Methods for DC Resistance or Conductance of Insulating Materials
D495 Test Method for High-Voltage, Low-Current, Dry Arc Resistance of Solid Electrical Insulation
D618 Practice for Conditioning Plastics for Testing
D638 Test Method for Tensile Properties of Plastics
D747 Test Method for Apparent Bending Modulus of Plastics by Means of a Cantilever Beam
D785 Test Method for Rockwell Hardness of Plastics and Electrical Insulating Materials
D1003 Test Method for Haze and Luminous Transmittance of Transparent Plastics D882Test Method for Tensile Properties of
Thin Plastic Sheeting
D1708 Test Method for Tensile Properties of Plastics by Use of Microtensile Specimens
E96/E96M Test Methods for Water Vapor Transmission of Materials
E308 Practice for Computing the Colors of Objects by Using the CIE System
2.2 TAPPI Standard:
3
Test Method T 451-CM-484 Flexural Properties of Paper
2.3 Federal Standards:
4
FED STD 191 Method 5204 Stiffness of Cloth, Directional; Self Weighted Cantilever Method
4
FED STD 191 Method 5206 Stiffness of Cloth Drape and Flex; Cantilever Bending Method
1
This practice is under the jurisdiction of ASTM Committee G03 on Weathering and Durability and is the direct responsibility of Subcommittee G03.04 on Biological
Deterioration.
CurrenteditionapprovedJan.10,2002.PublishedMay2002.OriginallypublishedasD1924–61.LastpreviouseditionD1924–90.RedesignatedG21in1970(Reapproved
1990). DOI: 10.1520/G0021-96R02.
Current edition approved Dec. 1, 2009. Published March 2010. Originally approved in 1961. Last previous edition approved in 2002 D1924 – 96(02). Redesignated G21
in 1970 (Reapproved 1990). DOI: 10.1520/G0021-09.
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from Technical Association of the Pulp and Paper Industry, Technology Park/Atlanta, P.O. Box 105113, Atlanta, GA 30348.
3
Available from Technical Association of the Pulp and Paper Industry (TAPPI), 15 Technology Parkway South, Norcross, GA 30092, http://www.tappi.org.
4
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1
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G21–09
3. Summary of Practice
3.1 Theproceduredescribedinthispracticeconsistsofselectionofsuitablespecimensfordeterminationofpertinentproperties,
inoculation of the specimens with suitable organisms, exposure of inoculated specimens under conditions favorable to growth,
examinationandratingforvisualgrowth,andremovalofthespecimensandobservationsfortesting,eitherbeforecleaningorafter
cleaning and reconditioning.
NOTE 1—Since the procedure involves handling and worki
...
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