ASTM E979-20

Standard Practice for Evaluation of Antimicrobial Agents as Preservatives for Invert Emulsion and Other Water Containing Hydraulic Fluids

SIGNIFICANCE AND USE
5.1 This procedure is designed to determine the effectiveness of antimicrobial agents intended for microbial control in invert emulsions and other water containing hydraulic fluids.
SCOPE
1.1 This laboratory practice is designed to evaluate the utility and effectiveness of antimicrobial agents intended to control microbial growth in invert emulsions and other water containing hydraulic fluids.  
Note 1: Procedures for preparation of water soluble hydraulic fluids and recovery of organisms appear in Practice E2169.  
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: 30-Nov-2020
• ICS: 75.120 - Hydraulic fluids
• Technical Committee: E35 - Pesticides, Antimicrobials, and Alternative Control Agents
• Drafting Committee: E35.15 - Antimicrobial Agents

Relations

• Refers: ASTM E2523-23 - Standard Terminology for Metalworking Fluids and Operations
• Effective Date: 01-Nov-2023
• Refers: ASTM D5465-16(2020) - Standard Practices for Determining Microbial Colony Counts from Waters Analyzed by Plating Methods
• Effective Date: 01-Jul-2020
• Refers: ASTM D1129-13(2020)e2 - Standard Terminology Relating to Water
• Effective Date: 01-May-2020
• Refers: ASTM E2523-13(2018) - Standard Terminology for Metalworking Fluids and Operations
• Effective Date: 01-Oct-2018
• Refers: ASTM D5465-16 - Standard Practices for Determining Microbial Colony Counts from Waters Analyzed by Plating Methods
• Effective Date: 01-Jun-2016
• Refers: ASTM E1326-15 - Standard Guide for Evaluating Non-culture Microbiological Tests Used for Enumerating Bacteria
• Effective Date: 01-May-2015
• Refers: ASTM E1326-13 - Standard Guide for Evaluating Nonconventional Microbiological Tests Used for Enumerating Bacteria
• Effective Date: 01-Oct-2013
• Refers: ASTM E2523-13 - Standard Terminology for Metalworking Fluids and Operations
• Effective Date: 01-Apr-2013
• Refers: ASTM E2169-12 - Standard Practice for Selecting Antimicrobial Pesticides for Use in Water-Miscible Metalworking Fluids
• Effective Date: 01-Nov-2012
• Refers: ASTM D5465-93(2012) - Standard Practice for Determining Microbial Colony Counts from Waters Analyzed by Plating Methods
• Effective Date: 01-Jun-2012
• Refers: ASTM E2694-11 - Standard Test Method for Measurement of Adenosine Triphosphate in Water-Miscible Metalworking Fluids
• Effective Date: 01-Aug-2011
• Refers: ASTM E2523-11 - Standard Terminology for Metalworking Fluids and Operations
• Effective Date: 01-Jan-2011
• Refers: ASTM D1129-10 - Standard Terminology Relating to Water
• Effective Date: 01-Mar-2010
• Refers: ASTM D4454-85(2009) - Standard Test Method for Simultaneous Enumeration of Total and Respiring Bacteria in Aquatic Systems by Microscopy (Withdrawn 2015)
• Effective Date: 01-May-2009
• Refers: ASTM E2694-09 - Standard Test Method for Measurement of Adenosine Triphosphate in Water-Miscible Metalworking Fluids
• Effective Date: 01-May-2009

Overview

ASTM E979-20 is the internationally recognized standard practice for evaluating the effectiveness of antimicrobial agents used as preservatives in invert emulsions and other water-containing hydraulic fluids. This standard supports manufacturers, formulators, and operators in determining the utility of antimicrobial agents to control microbial growth in high-water-content hydraulic fluids, which are particularly susceptible to biodeterioration by bacteria and fungi. By following the protocols outlined, stakeholders can assess and compare antimicrobial performance, ensuring hydraulic systems remain efficient, safe, and cost-effective.

Key Topics

• Microbial Control: The standard outlines methods to evaluate how well antimicrobial agents prevent or control the proliferation of bacteria, fungi, and other microorganisms in hydraulic fluids.
• Test Procedures: Laboratory-based procedures involve challenging emulsions with a heavy inoculum of bacteria or fungi and monitoring microbial activity over a simulated operational period.
• Simulated Hydraulic Systems: Testing is conducted using emulsion systems equipped with simulated filter assemblies to mimic real-world hydraulic circuit conditions.
• Performance Assessment: The bioburden (microbial population) is periodically quantified using established microbiological methods, including plate counts and microscopy.
• Interpretation of Results: Efficiency of preservatives is determined by monitoring signs of fouling, slime production, or filter plugging as well as changes in microbial titers. Comparison with untreated controls helps determine the duration and degree of antimicrobial protection.

Applications

The practical value of ASTM E979-20 extends to a variety of sectors using water-containing hydraulic fluids, including:

• Industrial Hydraulic Systems: Used in manufacturing, mining, and metalworking for fire-resistant and cost-efficient hydraulic circuits.
• Maintenance and Operations: Maintenance teams benefit by identifying effective antimicrobial agents to reduce system downtime and mitigate problems like filter plugging, malodors, and equipment degradation.
• Product Development: Manufacturers of hydraulic fluids and biocides use this standard to validate the efficacy of new or improved antimicrobial additives, ensuring product reliability and regulatory compliance.
• Quality Assurance: Routine fluid monitoring and validation studies help optimize fluid life and maintain high operational standards.
• Compliance and Safety: The standard provides a consistent approach aligned with international principles, supporting regulatory and safety goals.

Related Standards

Several key documents complement ASTM E979-20 by providing additional definitions, methodologies, and guidance:

• ASTM E2169: Practice for Selecting Antimicrobial Pesticides for Use in Water-Miscible Metalworking Fluids
• ASTM D1129: Terminology Relating to Water
• ASTM D5465: Practices for Determining Microbial Colony Counts from Waters Analyzed by Plating Methods
• ASTM E1326: Guide for Evaluating Non-culture Microbiological Tests
• ASTM E2523: Terminology for Metalworking Fluids and Operations
• ASTM E2694: Test Method for Measurement of Adenosine Triphosphate in Water-Miscible Metalworking Fluids

Practical Benefits

• Enhanced Fluid Longevity: Proactive evaluation helps choose preservatives that minimize biodeterioration, extending hydraulic fluid service life.
• Reduced Operational Costs: Prevents equipment fouling and unscheduled maintenance resulting from microbial contamination.
• Improved Workplace Safety: Controls risks associated with the generation of malodorous or potentially hazardous microbial byproducts in fluid systems.
• Global Alignment: Developed in accordance with WTO guidelines, ensuring international acceptance and applicability.

Keywords

antimicrobial agents, preservatives, invert emulsion, water-containing hydraulic fluids, microbial control, hydraulic system maintenance, ASTM E979-20, biocide evaluation, industrial fluid management, microbial contamination prevention

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: E979 − 20
Standard Practice for
Evaluation of Antimicrobial Agents as Preservatives for
Invert Emulsion and Other Water Containing Hydraulic
Fluids
This standard is issued under the fixed designation E979; 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.
INTRODUCTION
Invert emulsion hydraulic fluids typically contain 60% mineral oil and 40% water (by volume).
These fluids routinely are prepared using proprietary, oil-soluble, emulsifying agents, as well as other
emulsifiable constituents. They are recommended for use where conditions indicate a low-cost, fire
retardant product, compatible with water-based metal working fluids.
The high water content of these hydraulic fluids makes them susceptible to microbial attack.
Uncontrolled microbial growth in these fluids can cause cartridge filter unit plugging, maladorous
conditions, or general biodeterioration. Problem microorganisms associated with these fluids include
bacteria and fungi.
Thehydraulicsystemisessentiallyaclosedoneinwhichwaterofevaporationisaddedtomaintain
a fixed volume. The inclusion of an efficacious preservative in the water containing hydraulic fluids
can prevent microbial growth and the resulting problems that follow.
1. Scope* mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This laboratory practice is designed to evaluate the
utility and effectiveness of antimicrobial agents intended to
2. Referenced Documents
control microbial growth in invert emulsions and other water
containing hydraulic fluids. 2
2.1 ASTM Standards:
D1129Terminology Relating to Water
NOTE 1—Procedures for preparation of water soluble hydraulic fluids
and recovery of organisms appear in Practice E2169.
D4454Test Method for Simultaneous Enumeration of Total
andRespiringBacteriainAquaticSystemsbyMicroscopy
1.2 The values stated in SI units are to be regarded as
(Withdrawn 2015)
standard. No other units of measurement are included in this
standard. D5465Practices for Determining Microbial Colony Counts
from Waters Analyzed by Plating Methods
1.3 This standard does not purport to address all of the
E1326Guide for Evaluating Non-culture Microbiological
safety concerns, if any, associated with its use. It is the
Tests
responsibility of the user of this standard to establish appro-
E2169Practice for Selecting Antimicrobial Pesticides for
priate safety, health, and environmental practices and deter-
Use in Water-Miscible Metalworking Fluids
mine the applicability of regulatory limitations prior to use.
E2523Terminology for Metalworking Fluids and Opera-
1.4 This international standard was developed in accor-
tions
dance with internationally recognized principles on standard-
E2694Test Method for Measurement ofAdenosineTriphos-
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- phate in Water-Miscible Metalworking Fluids
1 2
This practice is under the jurisdiction ofASTM Committee E35 on Pesticides, For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Antimicrobials, and Alternative Control Agents and is the direct responsibility of contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Subcommittee E35.15 on Antimicrobial Agents. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Dec. 1, 2020. Published December 2020. Originally the ASTM website.
approvedin1984.Lastpreviouseditionapprovedin2015asE979–09(2015).DOI: The last approved version of this historical standard is referenced on
10.1520/E0979-20. www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E979 − 20
3. Terminology 6.6 Simulated Filters:
6.6.1 Strainer, 3-in. epoxy coated, ⁄4-in. mesh gutter
3.1 Terms used in this practice are defined inTerminologies
strainer.
D1129 and E2523.
6.6.2 Screen, 16 by 18 in. fiberglass screening material.
4. Summary of Test Method
NOTE 4—Fiberglass mesh screening material (16 by 18 in.) is available
from any local hardware dealer.
4.1 The antimicrobial agent to be evaluated is incorporated
into an emulsion system by (a) addition to the aqueous phase
6.6.3 Wire, 20-gauge, galvanized or stainless steel.
employedinthepreparationoftheemulsion,(b)indosestothe
6.7 Tubing, ⁄4-in. ID Tygon.
formulatedsystem,or(c)byothermethodssuitableforthetest
NOTE 5—Tygon is available from most local laboratory supply houses.
compound.
6.8 T-Connectors, ⁄4-in. polypropylene.
4.2 A heavy bacterial or fungal inoculum, or both, is then
added.
6.9 Laboratory Blender—Any standard adjustable speed
laboratory blender having a 2-L capacity glass or metal
4.3 The resulting mixture is aerated and passed over the
container is satisfactory.
surface of a simulated filter system for a minimum period of
eight weeks either continuously or with shutdowns to simulate
6.10 Hypodermic Needle, 16-gauge needle.
actual operations conditions.
6.11 Microscope,Brightfieldmicroscopeequippedwith40×
4.4 The degree of microbial control is determined by
and 100× objectives.
periodically quantifying the bioburden in the emulsion by
6.12 Labware:
direct microscopic count (Test Method D4454), plate count
6.12.1 Culture Dishes—100 by 15 mm sterile culture dishes
(Practice D5465), or other appropriate method (Guide E1326)
made of glass or plastic are required for making standard plate
and visual observations for microbial fouling of the simulated
counts.
filter surface.
NOTE 6—Presterilized and disposable plastic petri dishes are available
NOTE 2—A knowledge of standard microbiological techniques is
from most local laboratory supply houses.
required for this procedure. It is also required that good laboratory
practices be followed throughout these tests. This means appropriate 6.12.2 Bacteriological Pipettes of 1.1 or 2.2-mL capacity.
containmentforthemicrobiologicalsystemsbeingevaluated.Thesystems
NOTE 7—Presterilized and disposable 1.1-mL bacteriological pipettes
should be maintained in an enclosure so that during the aeration process
are available from most local laboratory supply houses.
the mists and aerosols generated do not contaminate the laboratory
environment.
6.12.3 Water Dilution Bottles—Any sterilizable glass con-
tainershavinga150to200-mLcapacityandtightclosuresmay
5. Significance and Use
be used.
5.1 This procedure is designed to determine the effective-
NOTE 8—Milk dilution bottles of 160-mL capacity having screw-cap
ness of antimicrobial agents intended for microbial control in
closures are available from most local laboratory supply houses.
invert emulsions and other water containing hydraulic fluids.
6.12.4 Two-Liter Borosilicate Glass Beakers.
6. Apparatus
6.12.5 Bent Glass Rod.
6.12.6 Screw Cap Culture Tubes, autoclavable, 15 by 150
6.1 Air Supply—Any air source which is free from organic
mm.
vapors, organic matter, or other objectionable material may be
used.
6.13 Water Bath—Maintain at 46 6 2°C to anneal agar
based microbiological media.
NOTE 3—If desired, air may be sterilized as follows:
Pack two 150-mm long drying tubes (bulb type) loosely with glass
6.14 Aluminum Foil.
wool in a series with neoprene stoppers, glass tubing, and neoprene
tubing. Wrap loosely in aluminum foil and steam sterilize at 15 to 20 psi
7. Reagents and Materials
for 30 minutes. Cool to room temperature while still wrapped. In-line
pre-sterilization air filters are available from most local laboratory supply
7.1 Invert Emulsion Emulsifier.
houses.
7.2 Paraffınic Mineral Oil.
Insert into air line with bulbs on upstream side. Average lifetime in
continuous use is two weeks. Discard sooner if upstream filter becomes
7.3 Deionized or Distilled Water (>2 MOHM quality)
wet or contaminated with oil.
6.2 Colony Counter—Any one of several types may be
used. 4
The sole source of supply of the apparatus known to the committee at this time
is Billy Penn Corp., Philadelphia, PA 19122. If you are aware of alternative
6.3 Incubator—Any cabinet capable of maintaining a tem-
suppliers, please provide this information to ASTM International Headquarters.
perature of 35 6 1°C may be used.
Your comments will receive careful consideration at a meeting of the responsible
technical committee, which you may attend.
6.4 Test Cabinet—A large cabinet capable of maintaining a
The sole source of supply of a satisfactory emulsifier for the preparation of
temperature of 35 6 1°C, able to house several two litre
invertemulsionhydraulicfluids(Compound#5162)knowntothecommitteeatthis
beakers, and into which an air line can be introduced. time is the Lubrizol Co., Wickliffe, OH. If you are aware of alternative suppliers,
please provide this information to ASTM International Headquarters. Your com-
6.5 Sterilizer—Any suitable steam sterilizer capable of
ments will receive careful consideration at a meeting of the responsible technical
producing the conditions of sterilization is acceptable. committee, which you may attend.
E979 − 20
7.4 Gentamicin Sulfate. isolates in soybean-casein digest medium and the fungal
7 isolates in sabouraud dextrose broth until there are 10 CFU
7.5 Arlacel 80.
6 7
bacteriaor10 to10 CFUfungi,orboth,permL,respectively.
7.6 Tween 60.
7.10.2.2 Other microorganisms of particular interest (Ross-
moore and Szlatky) may be used such as: Pseudomonas
7.7 Phosphate Buffer— For serial dilutions.
fluorescens, Pseudomonas cepacia, Klebsiella pneumoniae,
7.8 Mineral oil, sterile.
Proteus mirabilis, Desulfovibrio desulfuricans, Aspergillus
7.9 Microbiological Media—General retrieval media con-
niger, Cephalosporium sp., Fusarium sp., Candida sp.
sistent with good microbiological practices are acceptable.
7.10.2.3 Equal mixtures of any two of the above bacterial
Examples are as follows:
species or two of the above mold species, or both, plus the
7.9.1 Soybean-Casein Digest Agar, U.S.P. XIX, Medium II.
Candidaspeciestoprovideafinaltiterof10 CFUbacteria,or
6 7
10 to 10 CFU fungi, or both, per mL, should be used as an
NOTE 9—Soybean-casein digest agar is available in dehydrated form
from most laboratory media supply houses. inoculum for the emulsion system.
7.9.2 Fluid Soybean-Casein Digest Medium, U.S.P. XIX,
7.11 Antimicrobial Agents—The chemical agents to be
Medium III.
evaluated as preservatives.
7.9.3 Sabouraud Dextrose Agar, U.S.P. XIX, Medium 20.
7.9.4 Sabouraud Dextrose Broth, U.S.P. XIX, Medium 21.
8. Preparation of Simulated Filters
7.9.5 Sulfate American Petroleum Institute (API) Agar, for
8.1 Cut the epoxy-coated, ⁄4-in. mesh gutter strainers 16 by
enumeration of sulfate reducing bacteria.
18 in. mesh fiberglass screening material into 3 by 5 in.
7.10 Inoculum:
sections. Secure the screening to the strainers with 20-gauge
7.10.1 The inoculum may vary according to the users’
wire or with staples.
requirements. It may be either undefined or defined.
8.2 Preparation of Aerators—Cut tubing (see 6.7) into
7.10.1.1 An undefined inoculum may consist of microor-
13-in. sections. Bend tubing in a circle and connect both ends
ganisms isolated from a “spoiled” invert emulsion hydraulic
usingaTconnector(see6.8).ConnectthirdarmofTconnector
fluid which exhibits microbiologically induced phase
to a 20-in. length of tygon tubing. Thi
...

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: E979 − 09 (Reapproved 2015) E979 − 20
Standard Practice for
Evaluation of Antimicrobial Agents as Preservatives for
Invert Emulsion and Other Water Containing Hydraulic
Fluids
This standard is issued under the fixed designation E979; 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.
INTRODUCTION
Invert emulsion hydraulic fluids typically contain 60 % mineral oil and 40 % water (by volume).
These fluids routinely are prepared using proprietary, oil-soluble, emulsifying agents, as well as other
emulsifiable constituents. They are recommended for use where conditions indicate a low-cost, fire
retardant product, compatible with water-based metal working fluids.
The high water content of these hydraulic fluids makes them susceptible to microbial attack.
Uncontrolled microbial growth in these fluids can cause cartridge filter unit plugging, maladorous
conditions, or general biodeterioration. Problem microorganisms associated with these fluids include
bacteria and fungi.
The hydraulic system is essentially a closed one in which water of evaporation is added to maintain
a fixed volume. The inclusion of an efficacious preservative in the water containing hydraulic fluids
can prevent microbial growth and the resulting problems that follow.
1. Scope*
1.1 This laboratory practice is designed to evaluate the utility and effectiveness of antimicrobial agents intended to control
microbial growth in invert emulsions and other water containing hydraulic fluids.
NOTE 1—Procedures for preparation of water soluble hydraulic fluids and recovery of organisms appear in Practice E2169.
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 safety, health, and healthenvironmental 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.
This practice 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, 2015Dec. 1, 2020. Published February 2016December 2020. Originally approved in 1984. Last previous edition approved in 20092015
as E979 – 09.E979 – 09(2015). DOI: 10.1520/E0979-09R15.10.1520/E0979-20.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E979 − 20
2. Referenced Documents
2.1 ASTM Standards:
D1129 Terminology Relating to Water
D4454 Test Method for Simultaneous Enumeration of Total and Respiring Bacteria in Aquatic Systems by Microscopy
(Withdrawn 2015)
D5465 Practices for Determining Microbial Colony Counts from Waters Analyzed by Plating Methods
E1326 Guide for Evaluating Non-culture Microbiological Tests
E2169 Practice for Selecting Antimicrobial Pesticides for Use in Water-Miscible Metalworking Fluids
E2523 Terminology for Metalworking Fluids and Operations
E2694 Test Method for Measurement of Adenosine Triphosphate in Water-Miscible Metalworking Fluids
3. Terminology
3.1 Terms used in this practice are defined in Terminologies D1129 and E2523.
4. Summary of Test Method
4.1 The antimicrobial agent to be evaluated is incorporated into an emulsion system by (a) addition to the aqueous phase employed
in the preparation of the emulsion, (b) in doses to the formulated system, or (c) by other methods suitable for the test compound.
4.2 A heavy bacterial or fungal inoculum, or both, is then added.
4.3 The resulting mixture is aerated and passed over the surface of a simulated filter system for a minimum period of eight weeks
either continuously or with shutdowns to simulate actual operations conditions.
4.4 The degree of microbial control is determined by periodically quantifying the bioburden in the emulsion by direct microscopic
count (Test Method D4454), plate count (Practice D5465), or other appropriate method (Guide E1326) and visual observations for
microbial fouling of the simulated filter surface.
NOTE 2—A knowledge of standard microbiological techniques is required for this procedure. It is also required that good laboratory practices be followed
throughout these tests. This means appropriate containment for the microbiological systems being evaluated. The systems should be maintained in an
enclosure so that during the aeration process the mists and aerosols generated do not contaminate the laboratory environment.
5. Significance and Use
5.1 This procedure is designed to determine the effectiveness of antimicrobial agents intended for microbial control in invert
emulsions and other water containing hydraulic fluids.
6. Apparatus
6.1 Air Supply—Any air source which is free from organic vapors, organic matter, or other objectionable material may be used.
NOTE 3—If desired, air may be sterilized as follows:
Pack two 150-mm long drying tubes (bulb type) loosely with glass wool in a series with neoprene stoppers, glass tubing, and neoprene tubing. Wrap
loosely in aluminum foil and steam sterilize at 15 to 20 psi for 30 minutes. Cool to room temperature while still wrapped. In-line pre-sterilization air filters
are available from most local laboratory supply houses.
Insert into air line with bulbs on upstream side. Average lifetime in continuous use is two weeks. Discard sooner if upstream filter becomes wet or
contaminated with oil.
6.2 Colony Counter—Any one of several types may be used.
6.3 Incubator—Any cabinet capable of maintaining a temperature of 35 6 1°C1 °C may be used.
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.
The last approved version of this historical standard is referenced on www.astm.org.
E979 − 20
6.4 Test Cabinet—A large cabinet capable of maintaining a temperature of 35 6 1°C,1 °C, able to house several two litre beakers,
and into which an air line can be introduced.
6.5 Sterilizer—Any suitable steam sterilizer capable of producing the conditions of sterilization is acceptable.
6.6 Simulated Filters:
6.6.1 Strainer, 3-in. epoxy coated, ⁄4-in. mesh gutter strainer.
6.6.2 Screen, 16 by 18 in. fiberglass screening material.
NOTE 4—Fiberglass mesh screening material (16 by 18 in.) is available from any local hardware dealer.
6.6.3 Wire, 20-gage,20-gauge, galvanized or stainless steel.
6.7 Tubing, ⁄4-in. ID Tygon.
NOTE 5—Tygon is available from most local laboratory supply houses.
6.8 T-Connectors, ⁄4-in. polypropylene.
6.9 Laboratory Blender—Any standard adjustable speed laboratory blender having a 2-L capacity glass or metal container is
satisfactory.
6.10 Hypodermic Needle, 16-gage16-gauge needle.
6.11 Microscope, Brightfield microscope equipped with 40× and 100× objectives.
6.12 Labware:
6.12.1 Culture Dishes—100 by 15 mm sterile culture dishes made of glass or plastic are required for making standard plate counts.
NOTE 6—Presterilized and disposable plastic petri dishes are available from most local laboratory supply houses.
6.12.2 Bacteriological Pipettes of 1.1 or 2.2-mL capacity.
NOTE 7—Presterilized and disposable 1.1-mL bacteriological pipettes are available from most local laboratory supply houses.
6.12.3 Water Dilution Bottles—Any sterilizable glass containers having a 150 to 200-mL capacity and tight closures may be used.
NOTE 8—Milk dilution bottles of 160-mL capacity having screw-cap closures are available from most local laboratory supply houses.
6.12.4 Two-Liter Borosilicate Glass Beakers.
6.12.5 Bent Glass Rod.
6.12.6 Screw Cap Culture Tubes, autoclavable, 15 by 150 mm.
The sole source of supply of the apparatus known to the committee at this time is Billy Penn Corp., Philadelphia, PA 19122. 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.
E979 − 20
6.13 Water Bath—Maintain at 46 6 2°C2 °C to anneal agar based microbiological media.
6.14 Aluminum Foil.
7. Reagents and Materials
7.1 Invert Emulsion Emulsifier.
7.2 Paraffınic Mineral Oil.
7.3 Deionized or Distilled Water (>2 MOHM quality)
7.4 Gentamicin Sulfate.
7.5 Arlacel 80.
7.6 Tween 60.
7.7 Phosphate Buffer— For serial dilutions.
7.8 Mineral oil, sterile.
7.9 Microbiological Media—General retrieval media consistent with good microbiological practices are acceptable. Examples are
as follows:
7.9.1 Soybean-Casein Digest Agar, U.S.P. XIX, Medium II.
NOTE 9—Soybean-casein digest agar is available in dehydrated form from most laboratory media supply houses.
7.9.2 Fluid Soybean-Casein Digest Medium, U.S.P. XIX, Medium III.
7.9.3 Sabouraud Dextrose Agar, U.S.P. XIX, Medium 20.
7.9.4 Sabouraud Dextrose Broth, U.S.P. XIX, Medium 21.
7.9.5 Sulfate American Petroleum Institute (API) Agar, for enumeration of sulfate reducing bacteria.
7.10 Inoculum:
7.10.1 The inoculum may vary according to the users’ requirements. It may be either undefined or defined.
7.10.1.1 An undefined inoculum may consist of microorganisms isolated from a “spoiled” invert emulsion hydraulic fluid which
The sole source of supply of a satisfactory emulsifier for the preparation of invert emulsion hydraulic fluids (Compound #5162) known to the committee at this time
is the Lubrizol Co., Wickliffe, OH. 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.
The sole source of supply of gentamicin sulfate known to the committee at this time is as Garamycin Reagent Solution, available in two concentrations of 10 and 50
mg/mL, from the Schering Corp., Kenilworth, NJ 07033. 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.
The sole source of supply of the reagents (Arlacel 80, Tween 60, and Sulfate API Agar) known to the committee at this time is Sigma Aldrich Co., St. Louis, MO 63178,
http://www.sigmaaldrich.com. 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.
The sole source of supply of the media, available in dehydrated form, known to the committee at this time is Baltimore Biological Laboratories, Cockeysville, MD or
Difco Laboratories, Detroit, 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.
E979 − 20
exhibits microbiologically induced phase generation, or which is known to have caused plugging of a hydraulic system filter due
to microbial slime, and grown in a nutrient medium.
7.10.1.2 An undefined inoculum may consist of the following: (1) equal volumes of fluid soybean-casein dig
...