ASTM D4200-82(2019)

Standard Test Method for Evaluating Inhibitory Effects of Ink Grids on Membrane Filters

SIGNIFICANCE AND USE
5.1 This test method may be applied to determine the suitability of grid-marked membrane filters for use in bacteriological culture techniques for the detection and enumeration of bacterial organisms.  
5.2 A particularly sensitive organism and growth conditions have been selected for this test method in order to maximize sensitivity to toxic materials possibly present in the inks used for grid-marking membrane filters.
SCOPE
1.1 This test method describes a procedure whereby the user of ink-gridded membrane filters in water quality studies can ascertain whether or not the grid lines are toxic and inhibitory to bacterial growth when the membrane and its entrapped bacteria are incubated on a suitable media.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

General Information

• Status: Published
• Publication Date: 31-Oct-2019
• ICS: 71.040.20 - Laboratory ware and related apparatus
• Technical Committee: D19 - Water
• Drafting Committee: D19.08 - Membranes and Ion Exchange Materials

Relations

• Replaces: ASTM D4200-82(2011) - Standard Test Method for Evaluating Inhibitory Effects of Ink Grids on Membrane Filters
• Effective Date: 01-Nov-2019
• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Refers: ASTM D1129-10 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2010
• Refers: ASTM D1129-06ae1 - Standard Terminology Relating to Water
• Effective Date: 01-Sep-2006
• Refers: ASTM D1129-06a - Standard Terminology Relating to Water
• Effective Date: 01-Sep-2006
• Refers: ASTM D1193-06 - Standard Specification for Reagent Water
• Effective Date: 01-Mar-2006
• Refers: ASTM D1129-06 - Standard Terminology Relating to Water
• Effective Date: 15-Feb-2006
• Refers: ASTM D1129-04 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2004
• Refers: ASTM D1129-04e1 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2004
• Refers: ASTM D1129-03a - Standard Terminology Relating to Water
• Effective Date: 10-Aug-2003
• Refers: ASTM D1129-03 - Standard Terminology Relating to Water
• Effective Date: 10-Mar-2003
• Refers: ASTM D1129-01 - Standard Terminology Relating to Water
• Effective Date: 10-Jul-2002
• Refers: ASTM D1129-02a - Standard Terminology Relating to Water
• Effective Date: 10-Jul-2002
• Refers: ASTM D1129-02 - Standard Terminology Relating to Water
• Effective Date: 10-Feb-2002
• Refers: ASTM D1129-99a - Standard Terminology Relating to Water
• Effective Date: 10-Feb-2002

Overview

ASTM D4200-82(2019): Standard Test Method for Evaluating Inhibitory Effects of Ink Grids on Membrane Filters is a critical international standard developed by ASTM for assessing whether the inks used to mark grids on membrane filters exhibit any inhibitory or toxic effects on bacterial growth. This test method is especially relevant for organizations conducting water quality studies and bacteriological culture techniques, where reliable detection and enumeration of bacterial organisms are essential. The method is designed to maximize sensitivity to potential toxic materials in ink and to ensure membrane filters are suitable for microbiological testing.

Key Topics

• Purpose of the Test: The standard provides a procedure to determine if ink grid markings on membrane filters are toxic or inhibitory to bacterial growth, which is crucial for accurate bacteriological analyses.
• Sensitive Detection: The test uses specific bacterial organisms and growth conditions that are particularly sensitive to toxic substances, enhancing the ability to detect even minimal inhibitory effects.
• Qualitative Evaluation: The method is qualitative, focusing on visual inspection of bacterial colony patterns and any inhibition around grid lines after incubation.
• Instrumentation and Materials: The procedure includes requirements for laboratory equipment such as incubators, membrane filtration units, sterile forceps, and specific media to ensure consistency and repeatability.
• Repeat Testing and Suitability: Membrane filters that repeatedly show inhibition of bacterial growth adjacent to ink grid lines are deemed unsuitable for microbiological applications.

Applications

• Water Quality Testing: Laboratories and water utilities use this standard to verify that ink-gridded membrane filters do not compromise the detection of bacterial contaminants in water samples.
• Microbial Enumeration: Environmental and food safety labs apply the method to ensure accurate enumeration of bacteria in environmental monitoring and quality control.
• Filter Qualification: Manufacturers and suppliers of membrane filters use ASTM D4200-82(2019) to qualify new products or ink formulations for compliance with microbiological testing standards.
• Research and Method Validation: Academic and regulatory researchers utilize the method when validating new grid-marking techniques or assessing the impact of material changes on filter performance.

Related Standards

• ASTM D1129: Terminology Relating to Water
• ASTM D1193: Specification for Reagent Water
• ISO 7704: Water Quality - Evaluation of Membrane Filters Used for Microbiological Analyses
• Other ASTM Water Testing Standards: These may include protocols for filter performance, membrane integrity, and microbial recovery.

Practical Value

By following ASTM D4200-82(2019), laboratories ensure that ink grid markings on membrane filters do not inhibit or interfere with microbial growth, thus maintaining the integrity and accuracy of bacteriological culture results. Regular use of this standard helps organizations:

• Demonstrate compliance with international water quality and microbiological testing requirements
• Validate the safety and effectiveness of membrane filters for use in regulated environments
• Identify and eliminate sources of false-negative results due to toxic inks or unsuitable materials

In conclusion, ASTM D4200-82(2019) is a foundational standard for ensuring membrane filters with grid markings are fit for purpose in critical microbiological applications, supporting public health protection and regulatory compliance.

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: D4200 − 82 (Reapproved 2019)
Standard Test Method for
Evaluating Inhibitory Effects of Ink Grids on Membrane
Filters
This standard is issued under the fixed designation D4200; 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 4. Summary of Test Method
4.1 A heavy bacterial suspension is filtered through a
1.1 Thistestmethoddescribesaprocedurewherebytheuser
of ink-gridded membrane filters in water quality studies can gridded membrane filter.The bacterial concentration employed
is sufficient to cover much of the membrane with bacterial
ascertain whether or not the grid lines are toxic and inhibitory
to bacterial growth when the membrane and its entrapped colonies.
bacteria are incubated on a suitable media.
4.2 After filtration the membrane is incubated on a suitable
medium and the distribution of the colonies and shape of the
1.2 The values stated in SI units are to be regarded as
colonies noted in the area around each grid line.
standard. No other units of measurement are included in this
standard.
5. Significance and Use
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 5.1 This test method may be applied to determine the
responsibility of the user of this standard to establish appro- suitability of grid-marked membrane filters for use in bacte-
priate safety, health, and environmental practices and deter- riological culture techniques for the detection and enumeration
mine the applicability of regulatory limitations prior to use. of bacterial organisms.
1.4 This international standard was developed in accor-
5.2 Aparticularly sensitive organism and growth conditions
dance with internationally recognized principles on standard-
have been selected for this test method in order to maximize
ization established in the Decision on Principles for the
sensitivity to toxic materials possibly present in the inks used
Development of International Standards, Guides and Recom-
for grid-marking membrane filters.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
6. Apparatus
6.1 Incubator, capable of maintaining temperatures of
2. Referenced Documents
44.5 6 0.2°C.
2.1 ASTM Standards:
6.2 Membrane Filtration Units.
D1129 Terminology Relating to Water
D1193 Specification for Reagent Water
6.3 Vacuum Source with trap vessel.
6.4 Forceps, blunt-nosed.
3. Terminology
6.5 Autoclave or other sterilizing equipment.
3.1 Definitions:
6.6 Expendables:
3.1.1 For definitions of terms used in this standard, refer to
6.6.1 Gridded membrane filters.
Terminology D1129.
6.6.2 1-mL and 10-mL pipets.
6.6.3 Petri dishes (50-mm) containing 6 to 8 mL of agar
medium or a 100-mm dish with 20 6 2 mLof agar medium, or
This test method is under the jurisdiction of ASTM Committee D19 on Water
both.
and is the direct responsibility of Subcommittee D19.08 on Membranes and Ion
Exchange Materials. 6.6.4 Erlenmeyer flasks.
Current edition approved Nov. 1, 2019. Published January 2020. Originally
approved in 1982. Last previous edition approved in 2011 as D4200 – 82 (2011).
7. Reagents and Materials
DOI: 10.1520/D4200-82R19.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
7.1 Purity of Water—Unless otherwise indicated, reference
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
to water shall be understood to mean reagent water confor
...