ASTM E723-97(2002)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:E723–97 (Reapproved 2002)
Standard Test Method for
Efficacy of Antimicrobials as Preservatives for Aqueous-
Based Products Used in the Paper Industry (Bacterial
Spoilage)
This standard is issued under the fixed designation E 723; 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.
1. Scope 3.1.2 bactericide, n—an agent that kills bacteria. This term
is applied to chemical agents that kill bacteria but not neces-
1.1 This laboratory test method is used to determine the
sarily bacterial spores.
efficacy of an antimicrobial for preventing bacterial spoilage of
3.1.3 preservatives, n—a chemical or physical agent used to
in-process aqueous-based products used in the paper industry.
prevent microbial spoilage of products.
For information on fungal spoilage, see Test Method E 875.
This test method should be performed by persons who have
4. Summary of Test Method
had basic microbiological training.
4.1 Aqueous material to be preserved is inoculated with an
1.2 This standard does not purport to address all of the
appropriate microbial inoculum followed by addition of a
safety concerns, if any, associated with its use. It is the
concentration of bactericide that will kill the microbes and
responsibility of the user of this standard to establish appro-
prevent their growth for a desired period of time. Microbial
priate safety and health practices and determine the applica-
numbers in the sample are determined at various time periods
bility of regulatory limitations prior to use.
andcomparedtoacontolwithoutanybiocide.Theproperlevel
2. Referenced Documents of antimicrobial is one that reduces and keeps the organisms to
an acceptable level in the test material.
2.1 ASTM Standards:
D 1193 Specification for Reagent Water
5. Significance and Use
E 875 TestMethodforEfficacyofFungalControlAgentsas
5.1 This test method should be used to determine if an
Preservatives for Aqueous Based Products Used in the
antimicrobial prevents spoilage by bacteria and preserves
Paper Industry
pigment suspensions, dye solutions, pulp slurries, starch solu-
E 1054 Practices for Evaluating Inactivators of Antimicro-
tions, polymers, sizing agents, latex emulsions, and other
bial Agents Used in Disinfectant, Sanitizer, Antiseptic, or
aqueous-based materials used in the paper industry.
Preserved Products
E 1326 Guide for Evaluating Nonconventional Microbio-
6. Apparatus
logical Tests Used for Enumerating Bacteria
6.1 Balance—Two balances: one should be sensitive to 0.1
g at a load of 200 g and have a platform to accomodate bottles
3. Terminology
being used in the test. The second balance (analytical) should
3.1 Definitions of Terms Specific to This Standard:
be sensitive to 0.1 mg and should be employed to weigh the
3.1.1 antimicrobial, n—chemicalorphysicalagentthatkills
candidatepreservativetobeusedinthepreparationofthestock
microorganisms.
solutions.
6.2 Bottles—Borosilicateglassmilkdilutionbottlesorother
suitable containers fitted either with screw caps or Escher
This test method is under the jurisdiction of ASTM Committee E35 on
rubber stoppers. These bottles are used for water blanks and
Pesticides and Alternative Control Agents and is the direct responsibility of
aqueous-based samples.
Subcommittee E35.15 on Antibacterial and Antiviral Agents.
6.3 Colony Counter—Anyoneofseveraltypesmaybeused
Current edition approved April 10, 1997. Published June 1997. Originally
published as E 723 – 80. Last previous edition E 723 – 91.
as the Quebec, Buck, and Wolfhuegel. A hand tally for the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
recording of the bacterial count is recommended if manual
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
counting is done. Alternatively, an automated video colony
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. counter may also be used.
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E723–97 (2002)
6.4 Culture Tube Closures—Appropriate nontoxic closures 8.3 The material under test should be inoculated with
should be selected. sufficient microorganisms either from pure cultures or con-
6.5 Culture Tubes—Recommended size is 15 by 125 mm or tained in the spoiled material used as the inoculum to give a
18 by 150 mm without lip, and preferably of borosilicate glass. bacterial count of 1 000 000/mL or higher.
6.6 Blender—Any blender that will assure proper agitation
9. Procedure
and blending.
9.1 Dispense 50-g aliquots (or any other suitable quantity)
6.7 Flaming Equipment—Depending upon circumstances,
of the inoculated test material aseptically into sterile bottles (if
either an alcohol lamp or bunsen burner may be used to flame
necessary add nutrient). Treat the samples immediately with
inoculating needles and other equipment.
appropriate concentrations of the antimicrobial. Set up controls
6.8 Incubators, capable of maintaining temperatures of 28
in duplicate. Note appropriate physical characteristics such as
to 70 6 1°C to provide proper incubation temperatures.
pH, color, odor, viscosity etc., of all test samples at this time.
Temperature should be consistent with the temperature of the
9.1.1 Make the following additions aseptically to each
product to be preserved.
bottle in the order named and shake vigorously after each
6.9 Petri Dishes, 100 by 15-mm, plastic or borosilicate
addition, using 20 complete cycles in a vertical motion.
glass, sterile.
9.1.2 Add the desired volume of the stock solution of the
6.10 pH Measurement—AnyreliablepHmeterissuitableto
antimicrobial to be tested to give the desired concentration in
standardize the pH of the culture medium. Nonbleeding tests
parts per million or percent. Stock solution of the antimicrobial
strips are recommended for samples.
should be of such strength so that the volume of antimicrobial
6.11 Pipets, 1.1 or 2.2-mL milk dilution type, 1.0-mL
solution added is no more than 1 % of the total volume of
graduated in 0.01 mL, 10-mL graduated in 0.1 mL and
sample in each bottle. Do not add an antimicrobial to the
appropriately calibrated pipettors may be used. Serological
control. Include in each test a minimum of
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