ASTM D6006-97a

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
An American National Standard
Designation: D 6006 – 97a
Standard Guide for
Assessing Biodegradability of Hydraulic Fluids
This standard is issued under the fixed designation D 6006; 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 D 5480 Test for Motor Oil Volatility by Gas Chromatogra-
phy
1.1 This guide provides information to assist in planning a
D 5864 Test Method for Determining the Aerobic Aquatic
laboratory test or series of tests from which may be inferred
Biodegradation of Lubricants and Their Components
information about the biodegradability of an unused fully
E 1196 Test Method for Determining the Anaerobic Biodeg-
formulated hydraulic fluid in its original form. Biodegradabil-
radation Potential of Organic Chemicals
ity is one of three characteristics which are assessed when
2.2 ISO Standards:
judging the environmental impact of a hydraulic fluid. The
ISO 9439:1990 Technical Corrigendum I, Water Quali-
other two characteristics are ecotoxicity and bioaccumulation.
ty–Evaluation in an Aqueous Medium of the Ultimate
1.2 Biodegradability may be considered by type of environ-
Biodegradability of Organic Compounds
mental compartment: aerobic fresh water, aerobic marine,
ISO 4259:1992(E) Petroleum Products–Determination and
aerobic soil, and anaerobic media. Test methods for aerobic
Application of Precision Data in Relation to Methods of
fresh water, aerobic soil and anaerobic media have been
Test
developed that are appropriate for the concerns and needs of
2.3 OECD Standards:
testing in each compartment.
OECD 301B (the Modified Sturm Test) Guidelines for
1.3 This guide addresses releases to the environment that
Testing Chemicals
are incidental to the use of a hydraulic fluid but is not intended
OECD 301F (the Manometric Respirometry Test) Guide-
to cover situations of major, accidental release. The tests
lines for Testing of Chemicals
discussed in this guide take a minimum of three to four weeks.
Therefore, issues relating to the biodegradability of hydraulic
3. Terminology
fluid are more effectively addressed before the fluid is used,
3.1 Definitions:
and thus before incidental release may occur. Nothing in this
3.1.1 aerobic, adj—1. taking place in the presence of
guide should be taken to relieve the user of the responsibility
oxygen; 2. living or active in the presence of oxygen.
to properly use and dispose of hydraulic fluids.
3.1.2 anaerobic, adj—1. taking place in the absence of
1.4 This standard does not purport to address all of the
oxygen; 2. living or active in the absence of oxygen.
safety concerns, if any, associated with its use. It is the
3.1.3 biodegradation, n—the process of chemical break-
responsibility of the user of this standard to establish appro-
down or transformation of a substance caused by organisms or
priate safety and health practices and determine the applica-
their enzymes.
bility of regulatory limitations prior to use.
3.1.3.1 Discussion—Biodegradation is only one mechanism
2. Referenced Documents by which materials are transformed in the environment.
3.1.4 biomass, n—any material, excluding fossil fuels,
2.1 ASTM Standards:
which is or was a living organism or component of a living
D 5210 Test Method for Determining the Anaerobic Bio-
organism.
degradation of Plastic Materials in the Presence of Mu-
3.1.5 blank, n—in biodegradability testing, a test system
nicipal Sewage Sludge
containing all system components with the exception of the test
D 5291 Test Methods for Instrumental Determination of
substance.
Carbon, Hydrogen, and Nitrogen in Petroleum Products
3.1.6 environmental compartment, n—a subdivision of the
and Lubricants
environment based on physical or chemical properties, or both.
This guide is under the jurisdiction of ASTM Committee D02 on Petroleum
Products and Lubricants and is the direct responsibility of Subcommittee D02.12 on
Environmental Standards for Lubricants. Annual Book of ASTM Standards, Vol 11.03.
Current edition approved Dec. 10, 1997. Published June 1998. Originally Available from American National Standards Institute, 11 W. 42nd St., 13th
published as D 6006–96. Last previous edition D 6006–97. Floor, New York, NY 10036.
2 6
Annual Book of ASTM Standards, Vol 08.03. Available from the Organization for Economic Cooperation and Development,
Annual Book of ASTM Standards, Vol 05.03. 2 Rue Andre Pascal, S-75775, Paris CEDEX 16.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 6006 – 97a
3.1.6.1 Discussion—Examples of environmental compart- 5. Significance and Use
ments are aerobic fresh water, aerobic marine and aerobic soil.
5.1 This guide discusses ways to assess the likelihood that a
The results of test procedures may be applied to environmental
hydraulic fluid will undergo biodegradation if it enters an
compartments but the test systems do not constitute an envi-
environment that is known to support biodegradation of some
ronmental compartment.
substances, for example the material used as the positive
3.1.7 inoculum, n—spores, bacteria, single celled organisms
control in the test. The information can be used in making or
or other live materials that are introduced into a test medium.
assessing claims of biodegradability of a fluid formula.
3.1.8 preadaptation, n—the incubation of an inoculum in
5.2 Biodegradation occurs when a fluid interacts with the
the presence of the test substance which is done prior to the
environment, and so the extent of biodegradation is a function
initiation of the test and under conditions similar to the test
of both the chemical composition of the hydraulic fluid and the
conditions.
physical, chemical and biological status of the environment at
3.1.8.1 Discussion—The aim of preadaptation is to improve
the time the fluid enters it. This guide cannot assist in judging
the precision of the test method by decreasing variability in the
the status of a particular environment, so it is not meant to
rate of biodegradation produced by the inoculum. Preadapta-
provide standards for judging the persistence of a hydraulic
tion may mimic the natural processes which cause changes in
fluid in any specific environment either natural or man-made.
the microbial population of the inoculum leading to more rapid
5.3 If any of the tests discussed in this guide gives a high
biodegradation of the test substance, but it is not expected to
result, it implies that the hydraulic fluid will biodegrade and
change the final degree of biodegradation.
will not persist in the environmental compartment being
3.1.9 primary biodegradation, n—degradation of the test
considered. If a low result is obtained, it does not mean
substance resulting in a change in its physical or chemical
necessarily that the substance will not biodegrade in the
properties, or both.
environment, but does mean that further testing is required if a
3.1.10 primary biodegradation test, n—a test which follows
claim of biodegradability is to be made. Such testing may
the disappearance of a test substance by measuring some
include, but is not limited to, other tests mentioned in this guide
attribute of the substance.
or simulation tests for a particular environmental compartment.
3.1.10.1 Discussion—The extent to which the results of a
primary biodegradation test correspond to the biological con- 6. Test Methods
version of the test substance will depend on the attribute which
6.1 Aerobic Fresh Water Environment—The most com-
is being measured.
monly performed tests cover aerobic biodegradation in fresh
3.1.11 sonication, n—the act of subjecting a material to the
water. The tests conducted for this compartment may be
shearing forces of high-frequency sound waves.
ultimate biodegradation tests measuring CO production or
3.1.11.1 Discussion—Sonication of a two phase liquid sys-
primary biodegradation tests measuring the disappearance of
tem may result in the dispersal of one phase as fine droplets in
the test fluid. The test medium is based on high-grade,
the other phase.
carbon-free water. Some salts will be included as necessary for
3.1.12 ultimate biodegradation, n—degradation achieved
maintenance of solution pH and provision of trace minerals
when a substance is totally utilized by microorganisms result-
necessary for microbial life.
ing in the production of carbon dioxide (and possibly methane
6.1.1 The majority of ultimate biodegradation tests measure
in the case of anaerobic biodegradation), water, inorganic
produced CO . Examples of test procedures for ultimate
compounds and new microbial cellular constituents (biomass
biodegradability in an aerobic aquatic environment are: the
or secretions, or both).
Modified Sturm Test (OECD 301B); the Manometric
3.1.13 ultimate biodegradation test, n—a test which esti-
Respirometry Test (OECD 301F); the U.S. EPA Aerobic
mates the extent to which the carbon in a product is converted
Aquatic Biodegradation Test, which also is called the EPA
to CO or methane, either directly, by measuring the produc- 7
2 Shake Flask Test and was derived from the Gledhill Test (1);
tion of CO or methane, or, in the case of aerobic biodegrada-
Test Method D 5864; and the ISO Test 9439:1990. With the
tion, indirectly by measuring the consumption of O .
2 exception of Test Method D 5864, these tests were originally
3.1.13.1 Discussion—The measurement of new biomass
designed for water-soluble pure compounds and so the test
usually is not attempted.
procedures allow some procedural options that are not suitable
for water-insoluble substances, such as addition of the test
4. Summary of Guide
substance in an aqueous solution or calculation, rather than
4.1 This guide gives two kinds of information which relate
measurement, of carbon content. In other tests, such as the
to testing of hydraulic fluids for biodegradability. First, it gives
Manometric Respirometry Test, oxygen consumption is mea-
information of a general nature relating to biodegradability. For
sured as a surrogate for CO production. Oxygen consumption
example, it includes definitions of terms not traditionally used
is not a direct measure of ultimate biodegradation but is
by users or producers of hydraulic fluids (Section 3) and a brief
expected to correlate closely with it. The procedures listed are
discussion of some of the technical issues which are common
screening tests suitable for laboratory evaluation of the hydrau-
to most biodegradability tests when they are applied to
lic fluid. Although all the tests referred to above specify that the
hydraulic fluids (Section 7). Second, the guide gives more
specific information on the methods, advantages, and disad-
vantages of several of the biodegradation tests frequently used 7
The boldface numbers in parentheses refer to the list of references at the end of
for hydraulic fluids (Section 6). this standard.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 6006 – 97a
length of the test is 28 days, a high level of biodegradation in is typically the microbial community that naturally resides in
longer time frames can be taken as evidence that the hydraulic the soil sample used for the test. No further augmentation
fluid is ultimately biodegradable and nonpersistent in fresh generally is required. The sources of the soil samples should be
water. reported with test results. A low result in any soil test may not
mean that the hydraulic fluid will persist in an aerobic soil
6.1.1.1 If the biodegradability of a hydraulic fluid with a
environment, but does mean that more testing is required.
nonnegligible vapor pressure is measured in any one of these
tests, except the OECD 301F, a false negative may result. The 6.3.1 With modifications, published tests for aerobic bio-
hydraulic fluid could vaporize from the test solution before degradation in soils could be suitable for hydraulic fluids, but
conversion to CO . In this case a biodegradable fluid would none of the available standardized tests can be used as written.
have a low measured percent theoretical CO . If the aerobic In some cases only minor changes are necessary, such as
aquatic biodegradability of a volatile hydraulic fluid is to be development of a method for introduction of a water insoluble
measured, the OECD 301F test should be used. substance. Tests of soil biodegradation that currently are
available fall into three categories.
6.1.2 Tests for primary biodegradation must be designed for
specific classes of test substances. The results of a primary 6.3.1.1 First are those tests that follow CO production by
chemical means. An example of this kind of test has been
biodegradation test should not be considered equivalent to or
substitutable for the results of an ultimate biodegradation test. published by the U.S. FDA (8). These tests are suitable for
adaptation to assess the biodegradability of a hydraulic fluid in
6.1.2.1 The most commonly performed primary biodegra-
aerobic soils. Such adaptation may include different sample
dation test for lubricants is the CEC L-33-A-94 test, developed
handling procedures or changes in sample concentration. The
by the Coordinating European Council in the early 1980s and
U.S. FDA test is not suitable for testing volatile hydraulic
approved by the CEC in 1993. This test, which was called the
fluids.
CEC L-33-T-82 test prior to approval, measures the IR
6.3.1.2 Second are those that use test substances labeled
absorption spectrum of saturated carbons found in the test
materials. It was designed specifically for two-stroke outboard with radioactive tracers and follow the production of radioac-
tive CO , for example OECD 304A (6). These tests have the
engine lubricants; however, it is frequently used for measuring
the biodegradability of other lubricants. It is suitable for advantage of allowing the use of very low concentrations of
test substance, but are inappropriate for hydraulic fluids be-
measuring the primary biodegradation of hydraulic fluids if
cause hydraulic fluids are complex mixtures of many chemical
they have methylene hydrogens (-CH -) in their chemical
compounds, so the selection of an appropriate site for the label
structures. CEC results for some materials have
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