ASTM E645-07
(Test Method)Standard Test Method for Efficacy of Microbicides Used in Cooling Water Systems
Standard Test Method for Efficacy of Microbicides Used in Cooling Water Systems
SIGNIFICANCE AND USE
This test method determines potentially effective microbicides for use in cooling water systems using cooling water and deposits/biofilm obtained from the field. The addition of deposits/biofilms addresses the need to include the major source of microorganisms in cooling water systems. Even with this addition, laboratory results may not be totally predictive of microbicidal effectiveness in the field. This is because conditions in the field affecting microbicide effectiveness are difficult to mimic in the laboratory. These include blow down rate, addition of makeup water, water hardness, hydrocarbon leaks, pH, sediment loading, dissolved solids, microbes in slime, and deposits (biofilms) on surfaces. An additional factor is the difficulty in enumerating all microbes in the water due to the lack of adequate recovery media. Guidelines that address formation of and testing for surface-attached microbes (biofilms) may be found in Guides E 1427, while a guideline for unconventional measurement of microbes is found in Guide E 1326.
SCOPE
1.1 This test method outlines a procedure for evaluating the efficacy of microbicides (algicides, bactericides, and fungicides) that will be used for controlling microbial growth in cooling water systems. The microbicides will be evaluated using simulated or real cooling tower water against (1) microbes from cooling water, (2) microbes in microbiological deposits (biofilms) from operating cooling systems, or (3) microorganisms known to contaminate cooling water systems, or a combination thereof. This test method should be performed by individuals familiar with microbiological techniques.
1.2 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
Relations
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: E645 − 07
StandardTest Method for
1
Efficacy of Microbicides Used in Cooling Water 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 (´) indicates an editorial change since the last revision or reapproval.
3
1. Scope Biofilm (Withdrawn 2009)
1.1 This test method outlines a procedure for evaluating the
3. Terminology
efficacy of microbicides (algicides, bactericides, and fungi-
3.1 Definitions of Terms Specific to This Standard:
cides) that will be used for controlling microbial growth in
3.1.1 algicide, n—a chemical agent that kills algae; unicel-
cooling water systems. The microbicides will be evaluated
lular chlorophyll-containing plants.
using simulated or real cooling tower water against (1)
3.1.2 bactericides, n—aphysicalorchemicalagentthatkills
microbes from cooling water, (2) microbes in microbiological
deposits (biofilms) from operating cooling systems, or (3) bacteria, but not necessarily bacterial spores.
microorganisms known to contaminate cooling water systems,
3.1.3 biofilm, n—adynamic,self-organizedaccumulationof
or a combination thereof. This test method should be per-
microorganisms and environmental by-products immobilized
formed by individuals familiar with microbiological tech-
on a substrate and embedded in an organic polymer matrix.
niques.
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.
2
2.1 ASTM Standards:
3.1.6 cooling water, n—medium used to transfer heat in
D3731PracticesforMeasurementofChlorophyllContentof
cooling systems.
Algae in Surface Waters
3.1.7 fungicides, n—a physical or chemical agent that kills
D4012TestMethodforAdenosineTriphosphate(ATP)Con-
fungi;thatis,vegetativemyceliaand/orbuddingyeastsinclud-
tent of Microorganisms in Water
ing spores and/or conidia.
D4412TestMethodsforSulfate-ReducingBacteriainWater
3.1.8 microbial biofouling, n—the unwanted accumulation
and Water-Formed Deposits
of bacterial, fungal or algal cells, or any combination thereof
E1054Test Methods for Evaluation of Inactivators of Anti-
and their products on surfaces.
microbial Agents
Often this accumulation is accompanied by deposition of
E1326GuideforEvaluatingNonconventionalMicrobiologi-
organic and inorganic material.
cal Tests Used for Enumerating Bacteria
E1427Guide for Selecting Test Methods to Determine the
3.1.9 microbicides, n—a physical or chemical agent that
Effectiveness of Antimicrobial Agents and Other Chemi-
kills microorganisms.
cals for the Prevention, Inactivation and Removal of
4. Summary of Test Method
4.1 Microbicides are evaluated against microbes under con-
1
ditions simulating a cooling water system. Microbicides at
This test method is under the jurisdiction of ASTM Committee E35 on
Pesticides, Antimicrobials, and Alternative Control Agents and is the direct
concentrations that are expected to control the microbes are
responsibility of Subcommittee E35.15 on Antimicrobial Agents.
addedtocoolingwater.Atselectedtimeperiods,thenumberof
Current edition approved April 1, 2007. Published April 2007. Originally
microbes or measurable component of the microbes are deter-
approved in 1978. Last previous edition approved in 2002 as E645–02a. DOI:
10.1520/E0645-07. mined and compared to values at the start of the experiment.
2
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
3
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1
---------------------- Page: 1 ----------------------
E645 − 07
Bacteria (aerobic and anaerobic), fungi, and algae may be 6.10 Volumetric Flasks, 100 mL, are convenient for prepar-
detectedbyanumberofmethods,suchasplatecounting,Most ing
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.