ASTM E2315-16

Standard Guide for Assessment of Antimicrobial Activity Using a Time-Kill Procedure

SIGNIFICANCE AND USE
5.1 This procedure may be used to assess the in vitro reduction of a microbial population of test organisms after exposure to a test material.
SCOPE
1.1 This guide covers an example of a method that measures the changes in a population of aerobic microorganisms within a specified sampling time when antimicrobial test materials are present. Several options for organism selection and growth, inoculum preparation, sampling times and temperatures are provided. When the technique is performed as a specific test method, it is critical that the above mentioned variables have been standardized. Antimicrobial activity of specific materials, as measured by this technique, may vary significantly depending on variables selected. It is important to understand the limitations of in vitro tests, especially comparisons of results from tests performed with different parameters. As an example, test results of microorganisms requiring growth supplements or special incubation conditions may not be directly comparable to organisms evaluated without those stated conditions.  
1.2 Knowledge of microbiological techniques is required for this procedure.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 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 requirements prior to use.

General Information

• Status: Historical
• Publication Date: 14-Jan-2016
• ICS: 07.100.99 - Other standards related to microbiology
• Technical Committee: E35 - Pesticides, Antimicrobials, and Alternative Control Agents
• Drafting Committee: E35.15 - Antimicrobial Agents

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E2315 − 16
Standard Guide for
Assessment of Antimicrobial Activity Using a Time-Kill
1
Procedure
This standard is issued under the fixed designation E2315; 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 E1054 Test Methods for Evaluation of Inactivators of Anti-
microbial Agents
1.1 This guide covers an example of a method that measures
E2783 Test Method for Assessment of Antimicrobial Activ-
the changes in a population of aerobic microorganisms within
ity for Water Miscible Compounds Using a Time-Kill
a specified sampling time when antimicrobial test materials are
Procedure
present. Several options for organism selection and growth,
inoculum preparation, sampling times and temperatures are
3. Terminology
provided. When the technique is performed as a specific test
3.1 Definitions:
method, it is critical that the above mentioned variables have
3.1.1 inoculum suspension, n—the initial suspension of test
been standardized. Antimicrobial activity of specific materials,
organism used to inoculate the test material. This may also be
as measured by this technique, may vary significantly depend-
known as the organism inoculum (see 8.3).
ing on variables selected. It is important to understand the
3.1.2 microbial population, n—the microbial count (cfu/
limitations of in vitro tests, especially comparisons of results
mL) in the final volume of test material (see 9.4). This may also
from tests performed with different parameters. As an example,
be known as the “numbers control.” The measurement may be
test results of microorganisms requiring growth supplements or
taken at time zero which may be termed “Initial Population.”
special incubation conditions may not be directly comparable
Alternatively, the measurement may be taken at each exposure
to organisms evaluated without those stated conditions.
time or the longest exposure time used during testing to
1.2 Knowledge of microbiological techniques is required
simulate the test procedure which may be termed “Final
for this procedure.
Population.”
1.3 The values stated in SI units are to be regarded as
3.1.3 neutralization, n—the process for inactivating or
standard. No other units of measurement are included in this
quenching the activity of a test material. This may be achieved
standard.
through physical means (for example, filtration, dilution)
1.4 This standard does not purport to address all of the
and/or the addition of chemical agents, called neutralizers.
safety concerns, if any, associated with its use. It is the
3.1.4 neutralizer, n—a chemical agent used to inactivate,
responsibility of the user of this standard to establish appro-
neutralize, or quench the microbicidal properties of an antimi-
priate safety and health practices and determine the applica-
crobial agent.
bility of regulatory requirements prior to use.
3.1.5 total test volume, n—the volume of test material plus
2. Referenced Documents the volume of inoculum suspension.
2
2.1 ASTM Standards:
4. Summary of a Basic Test Method
D1193 Specification for Reagent Water
4.1 The test material or a dilution of the test material is
brought into contact with a known population of microorgan-
1
This guide is under the jurisdiction of ASTM Committee E35 on Pesticides, isms for a specified period of time at a specified temperature.
Antimicrobials, and Alternative Control Agents and is the direct responsibility of
An appropriate and specified neutralization technique is ap-
Subcommittee E35.15 on Antimicrobial Agents.
plied to quench the antimicrobial activity of the test material at
Current edition approved Jan. 15, 2016. Published March 2016. Originally
specified sampling intervals (for example, 30 s, 60 s, or any
approved in 2003. Last previous edition approved in 2008 as E2315 – 03(2008).
DOI: 10.1520/E2315-16.
range covering several minutes or hours), and the surviving
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
microorganisms are enumerated. The percent and/or log
10
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
reduction is calculated by comparison with the microbial
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. population.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E2315 − 16
5. Significance and Use organism in growth phase. The second transfer may be made
into a volume of growth medium that will provide a microbial
5.1 This procedure
...

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: E2315 − 03 (Reapproved 2008) E2315 − 16
Standard Guide for
Assessment of Antimicrobial Activity Using a Time-Kill
1
Procedure
This standard is issued under the fixed designation E2315; 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 guide covers examples an example of a basic method to measurethat measures the changes ofin a population of aerobic
microorganisms within a specified sampling time when tested against antimicrobial test materials in vitro.are present. Several
options for organism selection and growth, inoculum preparation, sampling times and temperatures are provided. When the basic
technique is performed as a specific test method, it is critical when evaluating the results to ensure that such that the above
mentioned variables have been standardized. Antimicrobial activity of specific materials, as measured by this technique, may vary
significantly depending on variables selected. It is important to understand the limitations of in vitro tests, especially comparisons
of results from tests performed underwith different circumstances.parameters. As an example, test results of microorganisms
requiring growth supplements,supplements or special incubation conditions,conditions may not be directly comparable to more
robust organisms under the conditions of a single procedure.organisms evaluated without those stated conditions.
1.2 Knowledge of microbiological techniques is required for this test.procedure.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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 and health practices and determine the applicability of regulatory requirements prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D1193 Specification for Reagent Water
E1054 Test Methods for Evaluation of Inactivators of Antimicrobial Agents
E2783 Test Method for Assessment of Antimicrobial Activity for Water Miscible Compounds Using a Time-Kill Procedure
3. Terminology
3.1 Definitions:
3.1.1 inoculum suspension, n—the initial suspension of test organism used to inoculate the test materialmaterial. This may also
be known as the organism inoculum (see 8.28.3).
3.1.2 microbial population, n—the microbial count (cfu/mL) in the final volume of test material (see 9.4). This may also be
known as the “initial population” or “numbers control.”“numbers control.” The measurement may be taken at time zero which may
be termed “Initial Population.” Alternatively, the measurement may be taken at each exposure time or the longest exposure time
used during testing to simulate the test procedure which may be termed “Final Population.”
3.1.3 neutralization, n—a process which results in the inactivation or quenching of the antimicrobial the process for inactivating
or quenching the activity of a test material. This may be achieved through dilution of the test material(s) or with the usephysical
means (for example, filtration, dilution) and/or the addition of chemical agents, called neutralizers, to reduce or quench the
antimicrobial activity.neutralizers.
1
This guide 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 April 1, 2008Jan. 15, 2016. Published May 2008March 2016. Originally approved in 2003. Last previous edition approved in 20032008 as
E2315 – 03.E2315 – 03(2008). DOI: 10.1520/E2315-03R08.10.1520/E2315-16.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E2315 − 16
3.1.4 neutralizer, n—a procedure or chemical agent used to inactivate, neutralize, or quench the microbiocidalmic
...