ASTM E2149-20
(Test Method)Standard Test Method for Determining the Antimicrobial Activity of Antimicrobial Agents Under Dynamic Contact Conditions
Standard Test Method for Determining the Antimicrobial Activity of Antimicrobial Agents Under Dynamic Contact Conditions
SIGNIFICANCE AND USE
5.1 Substrate–bonded, antimicrobial agents are not typically free to diffuse into their environment under normal conditions of use. This test method ensures good contact between the bacteria and the treated fiber, fabric, or other substrate, by constant agitation of the test specimen in a challenge suspension during the test period.
5.2 The metabolic state of the challenge species can directly affect measurements of the effectiveness of particular antimicrobial agents or concentrations of agents. The susceptibility of the species to particular biocides could be altered depending on its life stage (cycle). One-hour contact time in a buffer solution allows for metabolic stasis in the population. This test method standardizes both the growth conditions of the challenge species and substrate contact times to reduce the variability associated with growth phase of the microorganism.
5.3 Leaching of an antimicrobial is dependent upon the test conditions being utilized and the ultimate end use of the product. Additional testing may be required to determine if a compound is substrate-bound in all conditions or during the end use of the product.
5.4 This test method cannot determine if a compound is leaching into solution or is immobilized on the substrate. This test method is only intended to determine efficacy as described in subsequent portions of the method.
5.5 The test is suitable for evaluating stressed or modified specimens, when accompanied by adequate controls.
Note 1: Stresses may include laundry, wear and abrasion, radiation and steam sterilization, UV exposure, solvent manipulation, temperature susceptibility, or similar physical or chemical manipulation.
SCOPE
1.1 This test method is designed to evaluate the antimicrobial activity of antimicrobial-treated specimens under dynamic contact conditions. This dynamic shake flask test was developed for routine quality control and screening tests in order to overcome difficulties in using classical antimicrobial test methods to evaluate substrate-bound antimicrobials. These difficulties include ensuring contact of inoculum to treated surface (as in AATCC TM100), flexibility of retrieval at different contact times, use of inappropriately applied static conditions (as in AATCC TM147), sensitivity, and reproducibility.
1.2 This test method allows for the ability to evaluate many different types of treated substrates and a wide range of microorganisms. Treated substrates used in this test method can be subjected to a wide variety of physical/chemical stresses or manipulations and allows for the versatility of testing the effect of contamination due to such things as hard water, proteins, blood, serum, various chemicals, and other contaminants.
1.3 Surface antimicrobial activity is determined by comparing results from the test sample to controls run simultaneously.
1.4 This test method may not be appropriate for all types of antimicrobial-treated articles or antimicrobial agents. The proper test methodology should be determined based on antimicrobial mode of action and end-use expectations (Guide E2922)
1.5 Proper neutralization of all antimicrobials must be confirmed using Test Methods E1054.
1.6 This test method should be performed only by those trained in microbiological techniques.
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 This standard may involve hazardous materials, operations and equipment. 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in ...
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Standards Content (Sample)
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: E2149 − 20
Standard Test Method for
Determining the Antimicrobial Activity of Antimicrobial
Agents Under Dynamic Contact Conditions
This standard is issued under the fixed designation E2149; 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 1.8 This standard may involve hazardous materials, opera-
tions and equipment. This standard does not purport to address
1.1 This test method is designed to evaluate the antimicro-
all of the safety concerns, if any, associated with its use. It is
bial activity of antimicrobial-treated specimens under dynamic
the responsibility of the user of this standard to establish
contact conditions. This dynamic shake flask test was devel-
appropriate safety, health, and environmental practices and
oped for routine quality control and screening tests in order to
determine the applicability of regulatory limitations prior to
overcomedifficultiesinusingclassicalantimicrobialtestmeth-
use.
ods to evaluate substrate-bound antimicrobials. These difficul-
1.9 This international standard was developed in accor-
ties include ensuring contact of inoculum to treated surface (as
dance with internationally recognized principles on standard-
in AATCC TM100), flexibility of retrieval at different contact
ization established in the Decision on Principles for the
times, use of inappropriately applied static conditions (as in
Development of International Standards, Guides and Recom-
AATCC TM147), sensitivity, and reproducibility.
mendations issued by the World Trade Organization Technical
1.2 This test method allows for the ability to evaluate many
Barriers to Trade (TBT) Committee.
different types of treated substrates and a wide range of
2. Referenced Documents
microorganisms. Treated substrates used in this test method
canbesubjectedtoawidevarietyofphysical/chemicalstresses
2.1 ASTM Standards:
or manipulations and allows for the versatility of testing the
E1054Test Methods for Evaluation of Inactivators of Anti-
effect of contamination due to such things as hard water,
microbial Agents
proteins, blood, serum, various chemicals, and other contami-
E2756Terminology Relating toAntimicrobial andAntiviral
nants.
Agents
E2922Guide for The Use of Standard Test Methods and
1.3 Surface antimicrobial activity is determined by compar-
Practices for EvaluatingAntibacterialActivity onTextiles
ingresultsfromthetestsampletocontrolsrunsimultaneously.
2.2 AATCC Documents:
1.4 This test method may not be appropriate for all types of
AATCC TM147Antibacterial Activity Assessment of Tex-
antimicrobial-treated articles or antimicrobial agents. The
tile Materials: Parallel Streak Method
proper test methodology should be determined based on
AATCCTM100Antibacterial Finishes onTextile Materials:
antimicrobial mode of action and end-use expectations (Guide
Assessment of
E2922)
3. Terminology
1.5 Proper neutralization of all antimicrobials must be
confirmed using Test Methods E1054.
3.1 Fordefinitionsoftermsusedinthistestmethod,referto
E2756 Standard Terminology Relating to Antimicrobial and
1.6 This test method should be performed only by those
Antiviral Agents.
trained in microbiological techniques.
1.7 The values stated in SI units are to be regarded as
4. Summary of Test Method
standard. No other units of measurement are included in this
4.1 The antimicrobial activity of some substrate-bound,
standard.
antimicrobial agents is dependent upon direct contact of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
This test method is under the jurisdiction of ASTM Committee E35 on contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Pesticides, Antimicrobials, and Alternative Control Agents and is the direct Standards volume information, refer to the standard’s Document Summary page on
responsibility of Subcommittee E35.15 on Antimicrobial Agents. the ASTM website.
Current edition approved Sept. 15, 2020. Published October 2020. Originally Available from American Association of Textile Chemists and Colorists
approved in 2001. Last previous edition approved in 2013 as E2149–13a. DOI: (AATCC), P.O. Box 12215, Research Triangle Park, NC 27709, http://
10.1520/E2149-20. www.aatcc.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2149 − 20
microbes with the surface of the textile containing the active 6.6 Spectrophotometer,capableofmeasuringanabsorbance
chemical agent. This is particularly true for quaternary-silane of 475 nm.
typeagents.Thistestdeterminestheantimicrobialactivityofa
6.7 Sterile serological pipettes, capable of 50 and 10 mL
treated specimen by shaking samples of surface-bound mate-
capacity.
rials in a concentrated bacterial suspension for a one hour
6.8 Sterilizer, any suitable steam sterilizer producing the
contacttime.Thesuspensionisseriallydilutedbothbeforeand
conditions of sterility.
after contact and cultured. The number of viable organisms
from the suspension is determined and the percent reduction 6.9 Vortex mixer, to vortex dilution tubes during serial
(or log reduction) is calculated by comparing retrievals from
dilutions.
appropriate controls.
6.10 Water bath, for short term storage of liquefied agar
media, capable of maintaining 45 to 50°C.
5. Significance and Use
7. Reagents
5.1 Substrate–bonded,antimicrobialagentsarenottypically
free to diffuse into their environment under normal conditions
7.1 Buffer Solution—The following solution is prepared
of use. This test method ensures good contact between the
from reagent-grade chemicals. For buffer stock solution
bacteria and the treated fiber, fabric, or other substrate, by
(0.25M KH PO ): Prepare a fresh stock solution at least once
2 4
constant agitation of the test specimen in a challenge suspen-
every 6 months as follows: Weigh 34 6 0.1 g of potassium
sion during the test period.
dihydrogen phosphate into a 1000 mL beaker.Add 500 mL of
distilledwater.AdjustpHto7.2 60.1withadilutesolutionof
5.2 Themetabolicstateofthechallengespeciescandirectly
NaOH.Diluteto1000mL;transfertoaflaskandstoreat4°C.
affect measurements of the effectiveness of particular antimi-
Forworkingbuffersolution(0.3mMKH PO ):Prepareafresh
crobialagentsorconcentrationsofagents.Thesusceptibilityof
2 4
solution at least once every 2 months as follows:Transfer 1 6
thespeciestoparticularbiocidescouldbealtereddependingon
0.01 mL of stock buffer solution with a sterile pipette to flask
itslifestage(cycle).One-hourcontacttimeinabuffersolution
containing800mLofdistilledwater.Cap,sterilizeandstoreat
allows for metabolic stasis in the population. This test method
room temperature.
standardizes both the growth conditions of the challenge
species and substrate contact times to reduce the variability
7.2 Media:
associated with growth phase of the microorganism.
7.2.1 Tryptic Soy Broth, prepared according to manufactur-
er’s directions.
5.3 Leaching of an antimicrobial is dependent upon the test
7.2.2 Plate Count Agar, prepared according to manufactur-
conditions being utilized and the ultimate end use of the
er’s directions.
product. Additional testing may be required to determine if a
compound is substrate-bound in all conditions or during the
7.3 Wetting Agent Surfactant—Agents must be shown by
end use of the product.
prior testing at the intended use concentration not to cause a
reduction or increase in bacterial numbers. DC Q2-5211 at
5.4 This test method cannot determine if a compound is
0.01 % final dilution of working buffer solution has been
leaching into solution or is immobilized on the substrate. This
shown to be effective.
test method is only intended to determine efficacy as described
in subsequent portions of the method.
8. Test Organism
5.5 The test is suitable for evaluating stressed or modified
8.1 Escherichia coli,AmericanTypeCultureCollectionNo.
specimens, when accompanied by adequate controls.
25922.
NOTE 1—Stresses may include laundry, wear and abrasion, radiation
8.1.1 Cultures of the test organism should be maintained
and steam sterilization, UV exposure, solvent manipulation, temperature
susceptibility, or similar physical or chemical manipulation. according to good microbiological practice and checked for
purity on a routine basis. Consistent and accurate testing
6. Apparatus
requires maintenance of a pure, uncontaminated test culture.
Avoidcontaminationbyuseofgoodsteriletechniqueinplating
6.1 Air displacement pipettes, Eppendorf or equivalent, 100
and transferring. Avoid mutation or reversion by strict adher-
to 1000 µL with disposable tips.
ence to monthly stock transfers. Check culture purity by
6.2 Analytical balance, to weigh chemicals and substrates
making streak plates periodically, observing for colonies char-
and to standardize inoculum delivery volumes by pipettes.
acteristic of Escherichia coli, and Gram-staining.
6.3 Glassware:
NOTE 2—This test method was developed and validated using ATCC
6.3.1 Contact Flask, 250 mL Erlenmeyer flask, capped,
No.25922asthetestorganism.Ifanalternativecultureisused,theresults
autoclavable.
must be reported as having been obtained using a modified test method. If
6.3.2 Test tubes, 18 × 150 mm rimless bacteriological test the test method is modified in any way, the report must also include a
tubes used for growing test organisms and for serial dilution.
6.4 Incubator,capableofmaintainingatemperatureof35 6
The sole supplier of DC Q2-5211 known to the committee at this time is Dow
2°C. Corning, Midland, MI. If you are aware of alternative suppliers, please provide this
information to ASTM International Headquarters. Your comments will receive
6.5 Shaker, wrist action, capable of aggressive agitation of
careful consideration at a meeting of the responsible technical committee, which
bacteria and substrate solutions. you may attend.
E2149 − 20
detailed description of all modifications made, including, but not limited
only” sample for the series being run. Add 50 6 0.5 mL of
to:testorganisms,media,buffer,contacttime,bacterialconcentration,etc.
workingdilutionofbacterialinoculumpreparedin10.2toeach
flask.
9. Parameters
12.3 Determine bacterial concentration of solution at the
9.1 Surface preparation or conditioning must be specified.
“0” time by performing serial dilutions and stan
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM 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: E2149 − 13a E2149 − 20
Standard Test Method for
Determining the Antimicrobial Activity of Antimicrobial
Agents Under Dynamic Contact Conditions
This standard is issued under the fixed designation E2149; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method is designed to evaluate the antimicrobial activity of non-leaching, antimicrobial-treated specimens under
dynamic contact conditions. This dynamic shake flask test was developed for routine quality control and screening tests in order
to overcome difficulties in using classical antimicrobial test methods to evaluate substrate-bound antimicrobials. These difficulties
include ensuring contact of inoculum to treated surface (as in AATCC 100),TM100), flexibility of retrieval at different contact
times, use of inappropriately applied static conditions (as in AATCC 147),TM147), sensitivity, and reproducibility.
1.2 This test method allows for the ability to evaluate many different types of treated substrates and a wide range of
microorganisms. Treated substrates used in this test method can be subjected to a wide variety of physical/chemical stresses or
manipulations and allows for the versatility of testing the effect of contamination due to such things as hard water, proteins, blood,
serum, various chemicals, and other contaminants.
1.3 Surface antimicrobial activity is determined by comparing results from the test sample to controls run simultaneously.
1.4 The presence of an antimicrobial that requires neutralizationThis test method may not be appropriate for all types of
antimicrobial-treated articles or antimicrobial agents. The proper test methodology should be determined based on antimicrobial
mode of action and end-use expectations (Guide E2922is determined by the post-test.)
1.5 Proper neutralization of all antimicrobials must be confirmed using Test Methods E1054.
1.6 This test method should be performed only by those trained in microbiological techniques.
1.7 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.8 This standard may involve hazardous materials, operations,operations and equipment. 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 safety, health, and healthenvironmental practices and determine the applicability of regulatory limitations prior
to use.
1.9 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.
This test method is under the jurisdiction of ASTM Committee E35 on Pesticides, Antimicrobials, and Alternative Control Agents and is the direct responsibility of
Subcommittee E35.15 on Antimicrobial Agents.
Current edition approved Oct. 1, 2013Sept. 15, 2020. Published December 2013October 2020. Originally approved in 2001. Last previous edition approved in 2013 as
E2149 – 13.E2149 – 13a. DOI: 10.1520/E2149-13A.10.1520/E2149-20.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2149 − 20
2. Referenced Documents
2.1 ASTM Standards:
E1054 Test Methods for Evaluation of Inactivators of Antimicrobial Agents
2.1 ASTM Standards:
E1054 Test Methods for Evaluation of Inactivators of Antimicrobial Agents
E2756 Terminology Relating to Antimicrobial and Antiviral Agents
E2922 Guide for The Use of Standard Test Methods and Practices for Evaluating Antibacterial Activity on Textiles
2.2 AATCC Documents:
AATCC 147TM147 Antibacterial Activity Assessment of Textile Materials: Parallel Streak Method
AATCC 100TM100 Antibacterial Finishes on FabricsTextile Materials: Assessment of
3. Terminology
3.1 For definitions of terms used in this test method, refer to E2756 Standard Terminology Relating to Antimicrobial and Antiviral
Agents.
4. Summary of Test Method
4.1 The antimicrobial activity of asome substrate-bound, non-leaching antimicrobial agentagents is dependent upon direct contact
of microbes with the surface of the textile containing the active chemical agent. This is particularly true for quaternary-silane type
agents. This test determines the antimicrobial activity of a treated specimen by shaking samples of surface-bound materials in a
concentrated bacterial suspension for a one hour contact time. The suspension is serially diluted both before and after contact and
cultured. The number of viable organisms from the suspension is determined and the percent reduction (or log reduction) is
calculated by comparing retrievals from appropriate controls.
5. Significance and Use
5.1 Chemically bonded, Substrate–bonded, antimicrobial agents are not typically free to diffuse into their environment under
normal conditions of use. This test method ensures good contact between the bacteria and the treated fiber, fabric, or other
substrate, by constant agitation of the test specimen in a challenge suspension during the test period.
5.2 The metabolic state of the challenge species can directly affect measurements of the effectiveness of particular antimicrobial
agents or concentrations of agents. The susceptibility of the species to particular biocides could be altered depending on its life
stage (cycle). One-hour contact time in a buffer solution allows for metabolic stasis in the population. This test method standardizes
both the growth conditions of the challenge species and substrate contact times to reduce the variability associated with growth
phase of the microorganism.
5.3 Leaching of an antimicrobial is dependent upon the test conditions being utilized and the ultimate end use of the product. For
example, water soluble antimicrobials will be prone to removal from the test surface using the method described in Section
Additional 13 but insoluble compounds will not. It is for this reason that the use of the term leaching throughout this document
is limited to only the testing conditions described herein. Totesting may be required to determine if a compound is
immobilizedsubstrate-bound in all conditions or during the end use of the product additional testing may be required.product.
5.4 This test method cannot determine if a compound is leaching into solution or is immobilized on the substrate. This test method
is only intended to determine efficacy as described in 4.5 and subsequent portions of the method.
4.5 This test method is intended to evaluate antimicrobial agents that are not removed from the surface by the aqueous testing
conditions, as evaluated by Section 13. If an antimicrobial agent that is shown to be removed from the surface by Section 13 is
utilized in this test methodology, controls must be included such that appropriate neutralization steps are including during recovery
and enumeration.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM 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.
Available from American Association of Textile Chemists and Colorists (AATCC), P.O. Box 12215, Research Triangle Park, NC 27709, http://www.aatcc.org.
E2149 − 20
5.5 The test is suitable for evaluating stressed or modified specimens, when accompanied by adequate controls.
NOTE 1—Stresses may include laundry, wear and abrasion, radiation and steam sterilization, UV exposure, solvent manipulation, temperature
susceptibility, or similar physical or chemical manipulation.
5. Definitions
5.1 Immobilized: The antimicrobial remains on the surface of the article throughout the test as determined by the absence of
bactericidal activity in Section 13. A neutralizer does not need to be included for this type of antimicrobial
5.2 Leaching: Removal of the antimicrobial from the surface by the test conditions being utilized, resulting in a concentration high
enough to cause bactericidal activity as defined in Section 13. A valid neutralizer must be utilized for this type of antimicrobial
6. Apparatus
6.1 Air displacement pipettes, Eppendorf or equivalent, 100 to 1000 μL with disposable tips.
6.2 Analytical balance, to weigh chemicals and substrates and to standardize inoculum delivery volumes by pipettes.
6.3 Glassware:
6.3.1 Contact Flask, 250 mL Erlenmeyer flask, capped, autoclavable.
6.3.2 Test tubes, 18 × 150 mm rimless bacteriological test tubes used for growing test organisms and for serial dilution.
6.4 Incubator, capable of maintaining a temperature of 35 6 2°C.2 °C.
6.5 Shaker, wrist action, capable of aggressive agitation of bacteria and substrate solutions.
6.6 Spectrophotometer, capable of measuring an absorbance of 475 nm.
6.7 Sterile serological pipettes, capable of 50 and 10 mL capacity.
6.8 Sterilizer, any suitable steam sterilizer producing the conditions of sterility.
6.9 Vortex mixer, to vortex dilution tubes during serial dilutions.
6.10 Water bath, for short term storage of liquefied agar media, capable of maintaining 45 to 50°C.50 °C.
7. Reagents
7.1 Buffer Solution—The following solution is prepared from reagent-grade chemicals. For buffer stock solution (0.25M KH PO ):
2 4
Prepare a fresh stock solution at least once every 6 months as follows: Weigh 34 6 0.1 g of potassium dihydrogen phosphate into
a 1000 mL beaker. Add 500 mL of distilled water. Adjust pH to 7.2 6 0.1 with a dilute solution of NaOH. Dilute to 1000 mL;
transfer to a flask and store at 4°C.4 °C. For working buffer solution (0.3mM KH PO ): Prepare a fresh solution at least once every
2 4
2 months as follows: Transfer 1 6 0.01 mL of stock buffer solution with a sterile pipette to flask containing 800 mL of distilled
water. Cap, sterilize and store at room temperature.
7.2 Media:
7.2.1 Tryptic Soy Broth, prepared according to manufacturer’s directions.
7.2.2 Plate Count Agar, prepared according to manufacturer’s directions.
E2149 − 20
7.3 Wetting Agent Surfactant—Agents must be shown by prior testing at the intended use concentration not to cause a reduction
or increase in bacterial numbers. DC Q2-5211 at 0.01 % final dilution of working buffer solution has been shown to be effective.
8. Test Organism
8.1 Escherichia coli, American Type Culture Collection No. 25922.
8.1.1 Cultures of the test organism should be maintained according to good microbiological practice and checked for purity on
a routine basis. Consistent and accurate testing requires maintenance of a pure, uncontaminated test culture. Avoid contamination
by use of good sterile technique in plating and transferring. Avoid mutation or reversion by strict adherence to monthly stock
transfers. Check culture purity by making streak plates periodically, observing for colonies characteristic of Escherichia coli, and
Gram-staining.
NOTE 2—This test method was developed and validated using ATCC No. 25922 as the test organism. If an alternative culture is used, the results must
be reported as having been obtained using a modified test method. If the test method is modified in any way, the report must also include a detailed
description of all modifications made, including, but not limited to: test organisms, media, buffer, contact time, bacterial concentration, etc.
8.1.2 Alternative organisms can be substituted depending on the end use of the product. However, the precision and bias statement
has been developed using Escherichia coli ATCC 25922. There is are no data to support a precision and bias statement for other
organisms at this point. Use of alternate organisms shall be included in the report, in addition to any other modification of media,
buffer, bacterial concentration, etc.
9. Parameters
9.1 Surface preparation or conditioning must be specified. Prior manipulation of the specimen may be required in order to
demonstrate maximum activity in a desired time frame and must be reported and compared to identically handled controls.
9.2 The weight, size, and material of construction of specimen must be specified.
9.3 Specimens should be prepared such that they can maximize agitation and are reflective of a recordable ratio of surface area
to test titer.
10. Preparation of Bacterial Inoculum
10.1 Grow a fresh 18 h shake culture of Escherichia coli in sterile Tryptic Soy Broth at 35 6 2°C prior to performing the test.
10.2 Dilute the culture with the sterile buffer solution until the solution has an absorbance of 0.28 6 0.02 at 475 nm, as measured
spectrophotometrically. This has a concentration of 1.5-3.0 × 10 CFU/mL. Dilute appropriately into sterile buffer solution to
obtain a final concentration of 1.5-3.0 × 10 CFU/mL. This solution will be the working bacterial dilution.
11. Test Specimen
11.1 Preparation of Test Specimen:
11.1.1 Fabric and Paper—Samples are selected on weight basis and weighed to 1.0 6 0.1 g.
11.1.2 Powder and Granular Material—Weigh to 1.0 6 0.1 g. The material must settle after shaking so that no specimen interferes
with the retrieval and counting techniques.
11.1.3 Other Solids (Surface Treatment)—Reduce the solid in size to fit into the flask or use a sterile wide-mouth bottle. Use a
2 2
specimen that gives 4 in. (25.8 cm ) of treated surface area. Specimen may also be selected on weight basis, 60.1 g, at the
discretion of the investigator. Care must be exercised during shaking not to break the flask or bottle. The untreated specimen of
The sole supplier of DC Q2-5211 known to the committee at this time is Dow Corning, Midland, MI. If you are aware of alternative suppliers, please provide this
information to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the responsible technical committee, which you may
attend.
E2149 − 20
the solid must not absorb the solution. If appropriate to the nature of the test specimen, it can be mo
...
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