kSIST-TP FprCEN/TR 18172:2025

SLOVENSKI STANDARD
01-april-2025
Določanje aerobne biološke razgradnje popolnoma formuliranih maziv v vodni
raztopini - Preskusna metoda na podlagi maziv, ki porabljajo O2 - Poročilo o študiji
Determination of aerobic biological degradation of fully formulated lubricants in an
aqueous solution — Test method based on O2-consumption Lubricants – study report
Bestimmung des aeroben biologischen Abbaus von fertig formulierten Schmierstoffen in
wässriger Lösung - Prüfverfahren auf der Grundlage des O2-Verbrauchs von
Schmierstoffen - Studienbericht
Ta slovenski standard je istoveten z: FprCEN/TR 18172
ICS:
75.100 Maziva Lubricants, industrial oils and
related products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

FINAL DRAFT
TECHNICAL REPORT
RAPPORT TECHNIQUE
TECHNISCHER REPORT
January 2025
ICS
English Version
Determination of aerobic biological degradation of fully
formulated lubricants in an aqueous solution - Test
method based on O2-consumption Lubricants - study
report
Bestimmung des aeroben biologischen Abbaus von
fertig formulierten Schmierstoffen in wässriger Lösung
- Prüfverfahren auf der Grundlage des O2-Verbrauchs
von Schmierstoffen - Studienbericht

This draft Technical Report is submitted to CEN members for Vote. It has been drawn up by the Technical Committee CEN/TC 19.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a Technical Report. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a Technical Report.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. FprCEN/TR 18172:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Background . 7
5 Principle of biodegradation testing . 8
6 Disturbance variables . 8
7 Test method EN 17181 . 9
8 Preparation of the ILS . 10
9 Results . 12
10 Precision results . 18
11 Discussion . 19
12 Conclusion and future method development . 24
Annex A (informative) Examples of a biodegradation curve . 25
Bibliography . 26

European foreword
This document (FprCEN/TR 18172:2025) has been prepared by Technical Committee CEN/TC 19
“Gaseous and liquid fuels, lubricants and related products of petroleum, synthetic and biological origin”,
the secretariat of which is held by NEN.
This document is currently submitted to the Vote on TR.
This document has been prepared under a Mandate M/430 of the European Commission, addressed to
CEN for the development of European standards for bio-lubricants in relation to bio-based product
aspects. It has been prepared by CEN/TC 19/WG 33 “bio-lubricants”, the secretariat of which is held by
DIN.
Introduction
[1]
Mandate M/430 of the European Commission addressed to CEN the development of a definition
[2]
standard for bio-lubricants. Currently, EN 16807 is the active standard to define a bio-lubricant.
EN 16807 defines a bio-lubricant as a lubricant fulfilling a minimum set of environmental requirements,
namely biodegradability, aquatic toxicity and content of renewable resources together with minimum
technical requirements depending on the application of the lubricant.
The aim of the definition standard was to create a transparent definition for a bio-lubricant and easy-to-
test parameters to enable customers to monitor products claiming to be a bio-lubricant, to ensure they
fulfil its requirements, independent of their composition or from third parties’ control.
For this reason, it is necessary to establish test methods which allow for the testing of these parameters
on finished formulated products.
Regarding the content of renewable resources and aquatic toxicity, existing standard test methods are
already suitable for finished formulated products. Due to the broad variety of water-soluble, emulsifiable
and poorly water-soluble organic substances these standard test methods offer various preparation
procedures enabling the testing of complex mixtures such as finished formulated products. In contrast,
existing test methods for measuring aerobic biodegradation are optimised for organic substances rather
than finished formulated products.
In TC19/WG 33 a new test method for measuring the biodegradation of finished formulated products,
namely EN 17181 [3], has been developed based on ISO 9439 [4] (itself based on OECD 301B [5]). The
new method includes improvements to sample preparation in order to overcome the difficulties of testing
poorly water-soluble organic substances, and aims to provide a standard method for measuring aerobic
biodegradation of finished formulated products with the best possible precision.
Additionally, it has been noted that most existing test methods lack a published precision statement.
Based on this new standard test method EN 17181, and with significant financial support from industrial
partners, an interlaboratory study was performed to determine the reproducibility (R) and the
repeatability (r) of this new test method.
Annex A provides an example of biodegradation curves
1 Scope
This document describes the background of test method EN 17181, its improvements compared to the
existing standard test methods for measuring aerobic biodegradation of organic substances and the
planning and execution of the interlaboratory study .
A variety of data collected in the development of the method and the interlaboratory study is provided in
this report, thereby supporting future activity associated with bio-lubricants and the definition of
standard requirements.
Aerobic biodegradation resulting in mineralisation of the organic material can be determined by
measuring released CO using an appropriate analytical technique.
EN 17181 specifies a procedure for determining the degree of aerobic degradation of organic material in
fully formulated bio-lubricants. This organic material is exposed in a synthetic aqueous medium under
laboratory conditions to an inoculum prepared from activated sludge. In contrast to existing test methods
measuring released CO this new method uses a precise sample preparation procedure for poorly water-
soluble organic material. Nevertheless, EN 17181 is also applicable to measuring the aerobic degradation
of organic material present within fully formulated lubricants which are water-soluble or emulsifiable.
NOTE In general, EN 17181 can be used to determine biodegradation of finished formulated lubricants, which
contain biobased material of unknown amount or do not contain biobased material at all.
All results and statistical data evaluation in this document are based on fresh water as test medium. Tests
in sea water are currently not part of EN 17181.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
organic material
total amount of all organic compounds present in a fully formulated lubricant.
3.2
aerobic biodegradation
consumption of organic materials by microorganisms in a biochemical process using oxygen resulting in
cleavage of chemical bonds and carbon dioxide (CO ) production providing energy and/or new biomass.
3.3
primary biodegradation
structural change (transformation) of an organic chemical compound by microorganisms resulting in the
loss of a specific property.
3.4
mineralisation / ultimate biodegradation
aerobic biodegradation of organic material by microorganisms to yield carbon dioxide, water and mineral
salts of any other elements present (mineralization) and new biomass
3.5
activated sludge
biomass produced in the aerobic treatment of wastewater by the growth of bacteria and other
microorganisms in the presence of dissolved oxygen
3.6
inoculum
sample of activated sludge used in degradation procedures described in this method
3.7
reference compound
organic compound of known biodegradability with a degradation degree of more than 60%
3.8
dissolved organic carbon
DOC
part of the organic carbon in water which cannot be removed by specified phase separation, for example
by centrifugation at 4000 rpm for 15 min or by membrane filtration using membranes with pores of 0,2
μm to 0,45 μm diameter
3.09
theoretically released amount of carbon dioxide
ThCO
theoretical maximum amount of CO released from total oxidation of a lubricant, calculated from TOC
content, expressed in this case as milligrams of CO evolved per milligram or gram of test compound
3.10
total organic carbon
TOC
amount of carbon bound in an organic compound
Note 1 to entry: Refer to ISO 8245 for further details<
3.11
lag phase
time from the start of a test until adaptation and selection of the degrading microorganisms is achieved
and the biodegradation degree of a chemical compound or organic matter has increased to about 10 % of
the theoretical maximum biodegradation
Note 1 to entry: It is expressed in days.
3.12
maximum level of biodegradation
Maximum biodegradation degree of a chemical compound or organic matter in a test, above which no
further biodegradation takes place during the test
Note 1 to entry: It is expressed as a percentage
3.13
biodegradation phase
time from the end of the lag phase of a test until about 90 % of the maximum level of biodegradation has
been reached
Note 1 to entry: It is expressed in days
3.14
plateau phase
time from the end of the biodegradation phase when the maximum level of biodegradation is reached
until the end of the test
3.15
pre-conditioning
pre-incubation of an inoculum under the conditions of the subsequent test in the absence of the test
chemical compound or organic matter, with the aim of improving the performance of the test by
acclimatization of the microorganisms to the test conditions
3.16
pre-exposure / pre-adaption
pre-incubation of an inoculum in the presence of the test chemical compound or organic matter under
test, with the aim of enhancing the ability of the inoculum to biodegrade the test material by adaptation
and/or selection of the microorganisms
3.17
repeatability
r
difference between two independent results obtained in the normal and correct operation of the same
method, for test material considered to be the same, within a short interval of time, under the same test
conditions, that is expected to be exceeded with a probability of 5 % due to random variation, can be
calculated using the following function:
r = fr(x)
where x is the average of the two test results being compared
3.18
repeatability
R
difference between two independent results obtained in the normal and correct operation of the same
method, for test material considered to be the same, under different test conditions, that is expected to
be exceeded with a probability of 5 % due to random variation, can be calculated using the following
function:
R = fR(x)
where x is the average of the two test results being compared.
4 Background
Test procedures to detect the elimination of surfactants in waste-waters were developed in the 1970s [6]
with the aim of reducing the amount of visible foamin
...