ASTM E645-02a

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Designation:E645–02a
Standard Test Method for
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Efficacy of Microbicides Used in Cooling Systems
This standard is issued under the fixed designation E645; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 3. Terminology
1.1 This test method outlines a procedure for evaluating the 3.1 Definitions of Terms Specific to This Standard:
efficacy of microbicides (algicides, bactericides, and fungi- 3.1.1 algicide, n—a substance that kills algae; unicellular
cides) that will be used for controlling microbial growth in chlorophyll-containing plants.
cooling water systems. The microbicides will be evaluated 3.1.2 bactericides, n—anagentthatkillsbacteria.Thisterm
using simulated or real cooling tower water against microbes is applied to chemical agents that kill all bacteria, but not
from cooling water, microbiological deposits (biofilms) from necessarily bacterial spores.
operating cooling systems, or microorganisms known to con- 3.1.3 biofilm, n—anaccumulationofcellsimmobilizedona
taminatecoolingwatersystems,oracombinationthereof.This substratum and frequently embedded in an organic polymer
test method should be performed by individuals familiar with matrix of microbial origin.
microbiological techniques. 3.1.4 cooling system, n—an assemblage of equipment for
1.2 This standard does not purport to address all of the the removal of heat from processes or equipment, or both.The
safety concerns, if any, associated with its use. It is the most common medium used for removal or transfer of heat is
responsibility of the user of this standard to establish appro- water.Theheatedwaterthencanbedischargedintoareceiving
priate safety and health practices and determine the applica- body (once through cooling system) or it can be cooled and
bility of regulatory limitations prior to use. reused (recirculating cooling system).
3.1.5 cooling tower, n—a structure used to dissipate heat in
2. Referenced Documents
open recirculating cooling systems.
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2.1 ASTM Standards:
3.1.6 cooling water, n—medium used to transfer heat in
D3731 Practices for Measurement of Chlorophyll Content cooling systems, usual water.
of Algae in Surface Waters
3.1.7 fungicides, n—an agent that kills fungi (molds and
D4412 Test Methods for Sulfate-Reducing Bacteria in
yeasts) including fungal vegetative cells and spores.
Water and Water-Formed Deposits 3.1.8 microbial biofouling, n—the unwanted accumulation
E1054 Practices for Evaluating Inactivators of Antimicro-
of bacterial, fungal or algal cells, or any combination thereof
bialAgents Used in Disinfectants, Sanitizer,Antiseptic, or and their products on surfaces.
Preserved Products
Often this accumulation is accompanied by deposition of
E1326 Guide for Evaluating Nonconventional Microbio- organic and inorganic material.
logical Tests Used for Enumerating Bacteria
3.1.9 microbicides, n—an agent that kills microbes: bacte-
E1427 GuidesforSelectingTestMethodstoDeterminethe rial vegetative cells, fungal vegetative cells and spores, algae,
Effectiveness of Antimicrobial Agents and Other Chemi-
and protozoa.
cals for the Prevention, Inactivation, and Removal of
4. Summary of Test Method
Biofilm
4.1 Microbicides are evaluated against microbes under con-
ditions simulating a cooling water system. Microbicides at
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This test method is under the jurisdiction of ASTM Committee E35 on
concentrations that are expected to control the microbes are
Pesticides and is the direct responsibility of Subcommittee E35.15 onAntibacterial
addedtocoolingwater.Atselectedtimeperiods,theamountof
and Antiviral Agents.
microbes in the water is determined and compared to values at
Current edition approved October 10, 2002. Published January 2003. Original-
lyapproved 1978. Last previous edition approved in 2002 as E645–02.
the start of the experiment. Bacteria (aerobic and anaerobic),
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
fungi or algae, or both, may be detected by a number of
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
methods, such as plate counting, Most Probable Number
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. (MPN),adenosine-58-triphosphate(ATP).Theinvestigatorwill
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E645–02a
determine the minimal microbicide concentration for efficacy 6.12 Microscope,providesamagnificationof400to10003
based upon laboratory registration needs. and is comp
...