ASTM F838-15a

Standard Test Method for Determining Bacterial Retention of Membrane Filters Utilized for Liquid Filtration

SIGNIFICANCE AND USE
5.1 This test method is designed to assess the retentivity of a sterilizing filter under standard challenge conditions.  
5.1.1 A challenge of 107 bacteria per cm2 of effective filtration area is selected to provide a high degree of assurance that the filter will be challenged uniformly across the membrane surface to assure it will quantitatively retain large numbers of organisms. The model challenge organism, B. diminuta, is widely considered to be a small bacterium and is recognized as an industry standard for qualifying sterilizing filters. Other species may represent a worst-case test in terms of ability to penetrate a filter. This test does not provide assurance that filters can completely retain such bacteria.  
5.1.2 The analytical procedure utilized in this test method provides a method to assign a numerical value to the filtration efficiency of the filter being evaluated under standard filtration conditions. For the purpose of product sterility assurance, additional process-specific studies should be performed.
SCOPE
1.1 This test method determines the bacterial retention characteristics of membrane filters for liquid filtration using Brevundimonas diminuta as the challenge organism. This test method may be employed to evaluate any membrane filter system used for liquid sterilization.  
1.2 This test method is not intended to be used in performance of product- and process-specific validation of the bacterial retention characteristics of membrane filters to be used in pharmaceutical or biopharmaceutical sterilizing filtration, or both. Process- and product-specific bacterial retention validation should be carried out using the intended product manufacturing process parameters and the product solution or surrogate as the carrier fluid.  
1.3 The values stated in SI units are to be regarded as standard.  
1.3.1 Exception—The inch-pound values given for units of pressure are to be regarded as standard; SI unit conversions are shown in parentheses.  
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 limitations prior to use.

General Information

• Status: Historical
• Publication Date: 29-Sep-2015
• ICS: 07.100.20 - Microbiology of water
• Technical Committee: E55 - Manufacture of Pharmaceutical and Biopharmaceutical Products
• Drafting Committee: E55.03 - General Pharmaceutical Standards

Relations

• Replaces: ASTM F838-15 - Standard Test Method for Determining Bacterial Retention of Membrane Filters Utilized for Liquid Filtration
• Effective Date: 30-Sep-2015
• Referred By: ASTM D8422-21 - Standard Practice for Pre-Stressing Terminal Point-of-Use Water Filters before Testing by Test Method F838
• Effective Date: 30-Sep-2015

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: F838 − 15a
Standard Test Method for
Determining Bacterial Retention of Membrane Filters
1
Utilized for Liquid Filtration
ThisstandardisissuedunderthefixeddesignationF838;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
NOTE—Fig. 1 was editorially updated and the year date changed on Sept. 30, 2015.
1. Scope 3. Terminology
3.1 Definitions:
1.1 This test method determines the bacterial retention
characteristics of membrane filters for liquid filtration using 3.1.1 log reduction value—the logarithm to the base 10 of
Brevundimonas diminuta as the challenge organism. This test the ratio of the number of microorganisms in the challenge to
method may be employed to evaluate any membrane filter the number of organisms in the filtrate.
system used for liquid sterilization.
4. Summary of Test Method
1.2 This test method is not intended to be used in perfor-
4.1 After sterilization, the test filter is challenged with a
mance of product- and process-specific validation of the
3
suspensionof B. diminuta(ATCC19146 )ataconcentrationof
bacterial retention characteristics of membrane filters to be
7 2
10 organisms per cm of effective filtration area (EFA) at a
used in pharmaceutical or biopharmaceutical sterilizing
maximum differential pressure across the test filter of 30 psig
filtration, or both. Process- and product-specific bacterial
–3 2
(206 kPa) and a flow rate of 2 to4×10 LPM per cm of
retention validation should be carried out using the intended
effective filtration area. The entire filtrate is then filtered
product manufacturing process parameters and the product
through an analytical membrane filer disc, which is subse-
solution or surrogate as the carrier fluid.
quentlyincubatedonasolidifiedgrowthmedium.Microorgan-
1.3 The values stated in SI units are to be regarded as
ismsthatarenotretainedbythefilterbeingtestedwilldevelop
standard.
intovisiblecoloniesontheanalysismembraneandcanthenbe
1.3.1 Exception—The inch-pound values given for units of
enumerated.
pressurearetoberegardedasstandard;SIunitconversionsare
shown in parentheses.
5. Significance and Use
1.4 This standard may involve hazardous materials,
5.1 This test method is designed to assess the retentivity of
operations, and equipment. This standard does not purport to
a sterilizing filter under standard challenge conditions.
7 2
address all of the safety concerns, if any, associated with its
5.1.1 A challenge of 10 bacteria per cm of effective
use. It is the responsibility of the user of this standard to
filtration area is selected to provide a high degree of assurance
establish appropriate safety and health practices and deter-
that the filter will be challenged uniformly across the mem-
mine the applicability of regulatory limitations prior to use.
brane surface to assure it will quantitatively retain large
numbers of organisms. The model challenge organism, B.
2. Referenced Documents
diminuta, is widely considered to be a small bacterium and is
2
recognized as an industry standard for qualifying sterilizing
2.1 ASTM Standards:
D1193Specification for Reagent Water filters. Other species may represent a worst-case test in terms
of ability to penetrate a filter. This test does not provide
assurance that filters can completely retain such bacteria.
5.1.2 The analytical procedure utilized in this test method
1
This test method is under the jurisdiction of ASTM Committee E55 on
provides a method to assign a numerical value to the filtration
Manufacture of Pharmaceutical and Biopharmaceutical Products and is the direct
responsibility of Subcommittee E55.03 on General Pharmaceutical Standards. efficiency of the filter being evaluated under standard filtration
Current edition approved Sept. 30, 2015. Published October 2015. Originally
conditions. For the purpose of product sterility assurance,
approved in 1983. Last previous edition published in 2015 as F838–15. DOI:
additional process-specific studies should be performed.
10.1520/F0838-15A.
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
3
Standards volume information, refer to the standard’s Document Summary page on Available from American Type Culture Collection (ATCC), 10801 University
the ASTM website. Boulevard, Manassas, VA 20110, http://www.atcc.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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F838 − 15a
6. Apparatus 7.2.1 Additionally, any water used in this test method must
conformtotherequirementsfornon-bacteriostat
...

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: F838 − 15 F838 − 15a
Standard Test Method for
Determining Bacterial Retention of Membrane Filters
1
Utilized for Liquid Filtration
This standard is issued under the fixed designation F838; 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.
NOTE—Fig. 1 was editorially updated and the year date changed on Sept. 30, 2015.
1. Scope
1.1 This test method determines the bacterial retention characteristics of membrane filters for liquid filtration using
Brevundimonas diminuta as the challenge organism. This test method may be employed to evaluate any membrane filter system
used for liquid sterilization.
1.2 This test method is not intended to be used in performance of product- and process-specific validation of the bacterial
retention characteristics of membrane filters to be used in pharmaceutical or biopharmaceutical sterilizing filtration, or both.
Process- and product-specific bacterial retention validation should be carried out using the intended product manufacturing process
parameters and the product solution or surrogate as the carrier fluid.
1.3 The values stated in SI units are to be regarded as standard.
1.3.1 Exception—The inch-pound values given for units of pressure are to be regarded as standard; SI unit conversions are
shown in parentheses.
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 limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
D1193 Specification for Reagent Water
3. Terminology
3.1 Definitions:
3.1.1 log reduction value—the logarithm to the base 10 of the ratio of the number of microorganisms in the challenge to the
number of organisms in the filtrate.
4. Summary of Test Method
3 7
4.1 After sterilization, the test filter is challenged with a suspension of B. diminuta (ATCC 19146 ) at a concentration of 10
2
organisms per cm of effective filtration area (EFA) at a maximum differential pressure across the test filter of 30 psig (206 kPa)
–3 2
and a flow rate of 2 to 4 × 10 LPM per cm of effective filtration area. The entire filtrate is then filtered through an analytical
membrane filer disc, which is subsequently incubated on a solidified growth medium. Microorganisms that are not retained by the
filter being tested will develop into visible colonies on the analysis membrane and can then be enumerated.
5. Significance and Use
5.1 This test method is designed to assess the retentivity of a sterilizing filter under standard challenge conditions.
1
This test method is under the jurisdiction of ASTM Committee E55 on Manufacture of Pharmaceutical and Biopharmaceutical Products and is the direct responsibility
of Subcommittee E55.03 on General Pharmaceutical Standards.
Current edition approved May 1, 2015Sept. 30, 2015. Published May 2015October 2015. Originally approved in 1983. Last previous edition published in 20132015 as
F838 – 05 (2013).F838 – 15. DOI: 10.1520/F0838-15.10.1520/F0838-15A.
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.
3
Available from American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, VA 20110, http://www.atcc.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
F838 − 15a
7 2
5.1.1 A challenge of 10 bacteria per cm of effective filtration area is selected to provide a high degree of assurance that the
filter will be challenged uniformly across the membrane surface to assure it will quantitatively retain large numbers of organisms.
The model challenge organism, B. diminuta, is widely considered to be a small bacterium and is recognized as an industry standard
for qualifying sterilizing filters. Other species may represent a worst-case test in terms of ability to penetrate a filter. This test does
not provide assurance that filters can completely retain such b
...