ASTM E2169-01

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An American National Standard
Designation:E2169–01
Standard Practice for
Selecting Antimicrobial Pesticides for Use in Water-Miscible
Metalworking Fluids
This standard is issued under the fixed designation E 2169; 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 E 1326 Guide for Evaluating Nonconventional Microbio-
logical Tests Used for Enumerating Bacteria
1.1 This practice provides recommendations for selecting
E 1497 Practice for Safe Use of Water-Miscible Metal
antimicrobial pesticides (microbicides) for use in water-
Removal Fluids
miscible metalworking fluids (MWF). It presents information
E 2144 Practice for Personal Sampling and Analysis of
regarding regulatory requirements, as well as technical factors
Endotoxin in Metalworking Fluid Aerosols in Workplace
including target microbes, efficacy and chemical compatibility.
Atmospheres
1.2 This guide is not an encyclopedic compilation of all the
2.2 Government Standards:
concepts and terminology uses by chemists, microbiologists,
29 CFR 1910 Occupational Safety and Health Standards
toxicologists, formulators, plant engineers and regulatory af-
40 CFR 152 Pesticide Registration and Classification Pro-
fairs specialists involved in antimicrobial pesticide selection
cedures
and application. Instead, it provides a general understanding of
40 CFR 158 Pesticide Programs Data Requirements for
the selection process and its supporting considerations.
Registration
1.3 The values in SI units are to be regarded as the standard.
49 CFR 100-180 Research and Special Programs Adminis-
1.4 This standard does not purport to address all of the
tration, Department of Transportation
safety concerns, if any, associated with its use. It is the
PR Notice 2000-1 Applicability of the Treated Articles
responsibility of the user of this standard to establish appro-
Exemption to Antimicrobial Pesticides
priate safety and health practices and determine the applica-
Directive 98/8/EC of the European Parliament and of the
bility of regulatory limitations prior to use.
Council of 16 February 1998 concerning the placing of
2. Referenced Documents biocidal products on the market
2.1 ASTM Standards:
3. Terminology
D 1067 Test Methods for Acidity or Alkalinity of Water
3.1 active ingredient (a.i.), n—the chemical component or
D 1293 Test Methods for pH of Water
components of an antimicrobial pesticide that provides its
D 3519 Test Method for Foam in Aqueous Media (Blender
microbicidal performance.
Test)
3.2 activity spectrum, n—variety or range of microbes
D 3946 Test Method for Evaluating the Bacteria Resistance
against which an antimicrobial pesticide is effective.
of Water-Dilutable Metalworking Fluids
3 3.3 antimicrobial pesticide, n—chemical additive, regis-
D 4478 Test Methods for Oxygen Uptake
teredunder40CFR152,forusetoinhibitgrowth,proliferation
D 5465 Practice for Determining Microbial Colony Counts
or both of microorganisms.
from Waters Analyzed by Plating Methods
3.3.1 Discussion—Antimicrobial pesticides are registered
E 686 Method for Evaluation of Antimicrobial Agents in
for one or more end-use applications, or sites, for use within an
Aqueous Metal Working Fluids
approved dose range.
E 1302 Guide for Acute Animal Toxicity Testing of Water-
3.4 bactericide, n—antimicrobial pesticide specifically or
Miscible Metalworking Fluids
primarily effective against bacteria.
3.5 biocide, n—any chemical intended for use to kill or
inhibit organisms.
This practice is under the jurisdiction of ASTM Committee E34 on Occupa-
3.5.1 Discussion—Biocide is a term commonly used syn-
tional Health and Safety and is the direct responsibility of Subcommittee E34.50 on
Health and Safety Standards for Metalworking.
onymously with the preferred antimicrobial pesticide or mi-
Current edition approved October 10, 2001. Published December 2001.
crobicide.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. Code of Federal regulations available form United States Government Printing
Withdrawn Office, Washington, DC.
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E2169–01
3.6 bioburden, n—the level of microbial contamination a subset of the broader class of metalworking fluids. Conse-
(biomass) in a system. quences of uncontrolled microbial contamination in metal-
3.6.1 Discussion—Typically bioburden is defined in terms working fluids may include biodeterioration, rancidity and
of either biomass or numbers of cells per unit volume or mass aerosolization of potentially pathogenic microbes and toxic or
or surface area material tested (g biomass/mL sample; g allergenic microbial cell constituents. Consequently microbial
biomass/g sample; cell/mL sample, colony forming units contamination control is desirable from both operational and
(CFU)/mL, and so forth). industrial hygiene perspectives.
3.7 biodeterioration, n—the loss of commercial value, per-
4.2 Antimicrobial pesticides are used to prevent biodeterio-
formance characteristics or both of a product (metalworking
ration and may also reduce the risk of disease associated with
fluid) or material (coolant system or finished parts) through
the use of water-miscible metalworking fluids. They may be
biological processes.
used in-drum, on-site or both. Antimicrobial pesticides work
3.8 biofilm, n—a film or layer composed of microorgan-
either by killing microbes, inhibiting specific undesirable
isms, biopolymers, water, and entrained organic and inorganic
microbial activities or both in the treated fluid. Antimicrobial
debris that forms as a result of microbial growth, proliferation,
pesticides used in metalworking fluids include representatives
and excretion of polymeric substances at phase interfaces
from a number of chemical groups. Consequently, antimicro-
(liquid-liquid,liquid-solid,liquid-gas,andsoforth).(synonym:
bial pesticides vary widely in their mode of action, compat-
skinnogen layer).
ibility with other fluid components and other performance
3.9 bioresistant, adj—ability to withstand biological attack.
properties.
3.9.1 Discussion—Bioresistant, or recalcitrant, chemicals
4.3 The process of selecting an antimicrobial pesticide for
are not readily metabolized by microorganisms.
use in metalworking fluids shall include, minimally, confirma-
3.10 biostatic, adj—able to prevent existing microbial con-
tion that the product is (1) approved for the intended applica-
taminants from growing or proliferating, but unable to kill
tion; (2) compatible with other fluid and system constituents;
them.
and (3) effective. Other considerations including, but not
3.10.1 Discussion—Biostatic additives may be registered
limited to intended application, target microbes, desired speed
antimicrobial pesticides or unregistered chemicals with other
of action, performance persistence, handling precautions, toxi-
performance properties. The difference between biocidal and
cological properties, water and oil miscibility, and waste
biostatic performance may be attributed to dose, chemistry or
treatability may affect microbicide selection.
both.
4.4 Microbicide selection begins with a fundamental under-
3.11 contamination control, n—maintenance of bioburden
standing of the coolant formulation chemistry, biodeterioration
at an operationally defined level, at or below which the
control strategy and specific customer needs. General back-
bioburden does not affect the fluid or system adversely.
ground information regarding MWF system management is
3.12 demand, n—the sum of all factors that contribute to
available in Practice E 1497 and elsewhere. Armed with this
decreasing the effective concentration of antimicrobial pesti-
information, candidate microbicides can be selected for further
cide.
evaluation. Products that meet all of the selection criteria are
3.12.1 Discussion—Processes contributing to demand in-
ultimately tested in field application. Since antimicrobial pes-
clude, but are not limited to, reaction with microbes, reactions
ticide efficacy can diminish over time, the selection process
with other chemicals in the fluid, adsorption onto surfaces,
may be viewed as cyclic. Moreover, since microbicides can be
absorption into materials and temperature.
toxic,theyrequirerigorousandcompetentproductstewardship
3.13 dose, n—concentration of antimicrobial pesticide
throughout their use-cycle.
added to treated solution.
3.13.1 Discussion—Dose is generally expressed as either
5. Significance and Use
ppm active ingredient (a.i.) or ppm as supplied (a.s.).
3.14 fungicide, n—antimicrobial pesticide specifically or 5.1 This practice summarizes the steps in the antimicrobial
primarily effective against fungi. pesticide selection process, reviewing technical and regulatory
3.15 lethal dose, n—concentration at which treatment kills considerations inherent in the process. It complements and
at least one of test subjects. amplifies information provided in Practice E 1497.
3.15.1 Discussion—TheLD isthetermusedintoxicology
50 5.1.1 Steps in the antimicrobial selection process include:
defining the dose that kills fifty-percent of the test population.
needs identification, use strategy selection, efficacy testing,
3.16 half-life (T ⁄2 ), n—time required for concentration of a
chemical compatibility testing, regulatory consideration re-
microbicide to diminish to one-half its initial concentration.
view, handling and disposal issue review.
3.17 microbicide, n—synonymous with antimicrobial pesti-
5.2 This practice provides stakeholders in the microbicide
cide.
selectionprocessanoverviewofitscomplexities,includingthe
3.18 minimum inhibitory concentration (MIC), n—lowest
process of obtaining pesticide registration from cognizant
treatment-dose that will prevent test population from growing,
governing bodies.
proliferating or otherwise contributing to biodeterioration.
4. Summary of Practice
4.1 Microorganisms can grow in all water-miscible metal-
Organization Resources Counselors. Management of the Metal Removal Fluid
working fluids including water-miscible metal removal fluids, Environment. Web site: http://www.aware-services.com/orc/.2000.
E2169–01
5.3 Personnel responsible for antimicrobial pesticide selec- 6.2.7 Will the microbicide, either in-formulation or as
tion will be able to use this practice as a roadmap through the tank-side additive be used domestically only, or will it be
process. traded internationally? Industrial pesticide regulations differ
5.4 Personnel responsible for industrial hygiene, product or around the world. Not all products approved by the U.S. EPA
are approved in Canada, Europe or other industrialized regions
plant management will gain insight to the tradeoffs attendant
with antimicrobial use and selection. or vice versa. Moreover, registration and reporting require-
ments vary amongst nations. Global acceptability may be an
important consideration (see Section 10).
6. Needs Information
6.3 Completion of this needs analysis step will facilitate the
6.1 The first step in the microbicide selection process is the
balance of the microbicide selection process.
recognitionofaneed.Recognitionmaycomeasaconsequence
of new metalworking fluid formulation development or evolv-
7. Antimicrobial Pesticide Use Strategies
ing requirements in one or more fluid end-use applications.
6.1.1 Antimicrobial pesticide needs typically fall into either,
7.1 Microbicides may be added either in-formulation, tank-
or both of the following categories:
sideorboth.Users,understandinghowthemetalworkingfluids
6.1.1.1 Biodeterioration Prevention—The various strategies
they use are formulated, should select an appropriate pesticide
used to enhance coolant life.
use-strategy for each end-use application.
6.1.1.2 Health and Safety—Reducing the risk of employee
7.1.1 In-formulation microbicide use means that antimicro-
exposure to potentially pathogenic microbes or allergenic
bial(s) are formulated into coolant concentrate.
microbial constituents such as endotoxins (E 2144).
7.1.1.1 Microbicide addition at this stage may reduce or
6.2 Once the need has been recognized, the next step is to
eliminate the requirement for subsequent tankside addition. It
define the need operationally. This is achieved by determining
also protects high water-content formulations from spoilage
the answers to the needs analysis questions, for example:
during storage and transport.
6.2.1 What type of metalworking fluid formulation requires
7.1.1.2 When formulated into coolant, microbicides are
microbicidal augmentation? Antimicrobials vary in their re-
added at concentrations sufficient to provide adequate a.i. once
spective oil and water solubilities. Moreover, chemical incom-
the formulation has been diluted to end-use strength. In-drum
patibilities exist between certain antimicrobials and other
demand may reduce the residual microbicide concentration
metalworking fluid constituents. Microbicides that are deemed
availablebythetimecoolantconcentrateisdilutedforend-use.
inappropriate based on their incompatibility with the other
7.1.1.3 With coolants intended for a variety of end-use
formulation components need not be considered further (see
applications, each requiring different final coolant concentra-
9.1).
tions, it may be difficult to blend a single microbicide concen-
6.2.2 What are the desired performance-life and biodegrad-
tration in-drum. For example, assume that the target end-use
ability criteria for the finished formulation? Bioresistance and
microbicide concentration is 1,000 ppm and the expected
biodegradability need to be balanced. Waste treatability and
coolant finished dilution range is 5 to 10-percent. Blending
extended sump life are both important considerations. (see
microbicide into the formulation at 2-percent will yield the
Section 8).
desired1,000ppmwhenthecoolantisdilutedto5 %and2,000
6.2.3 What respective roles should antimicrobial pesticides
ppm when the coolant is diluted to 10-percent. The latter
and bioresistant performance additives play in achieving those
concentration may exceed the maximum microbicide concen-
criteria? Metalworking fluid formulators can select from a
tration permitted under the microbicide’s U.S. EPA pesticide
growing number of bioresistant corrosion inhibitors and other
registration. Using less microbicide in
...