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644 Lubricant Additives: Chemistry and Applications
material. New bearing materials such as Cronidur-30
®
, Rex20
®
(CRU20
®
), and CCS42L
®
[25] have
been developed that are more corrosion resistant and harder than the traditional tool—steel bear-
ing materials such as M50 and 52100. Higher hardness of these new bearing materials gives them
higher load-carrying capability. For high-speed precision bearings, hybrid bearings, utilizing the
lower-density silicon nitride rolling elements, are gaining popularity.
The lack of reactivity of these materials with the environment (including the lubricant/additive
system) that makes them effective at corrosion resistance also inhibits the formation of the bene -
cial surface lms for enhanced boundary lubrication performance. The state-of-the-art boundary
additives such as tricresylphosphate are not optimized for the newer chemical composition bear-
ing steels. To completely realize the bene ts of the new corrosion-resistant/harder bearing steels,
new additives are currently being developed under U.S. Air Force sponsorship through a program
involving oil companies, engine companies, and contractors. Similar additive development will
be required for optimized performance of bearings utilizing hard coatings on the balls and races.
These hard, wear-resistant coatings such as titanium carbonitride (TiCN)- [26] and titanium carbide
(TiC)-coated balls have been shown to extend the lifetime of bearings in critical applications, but in
most cases, they have been used either with no liquid-grease lubricant or with lubricants optimized
for steel-to-steel contacts. Again, the chemistry of the lubricity additives was optimized to react with
fresh steel (iron) asperities caused by contact in boundary lubrications. With the changed chemistry
of the surface of the bearing material from iron-based alloys to a hard coating, the typical lubricity
additives may not effectively provide the signi cant increase in lifetime as is typically experienced
with the steel bearings. In many cases, improved lifetimes are experienced with hybrid bearings
that incorporate a coated or ceramic ball and a standard steel race. However, with a fully ceramic
bearing or one that uses coated surfaces on both the ball and the race, the maximum enhancement
in performance cannot be experienced unless new additives are developed. These new additives
will bene cially interact with these new bearing surfaces to produce the lubricious coatings that
are believed to be the main mechanism resulting in the currently experienced wear improvement in
steel bearings with the state-of-the-art lubricity additives.
REFERENCES
1. Snyder, C.E., Jr., L.J. Gschwender. Development of a non ammable hydraulic uid for aerospace
applications over a
−54°C to 135°C temperature range. Lub Eng 36: 458–465, 1980.
2. Snyder, C.E., Jr. et al. Development of high temperature (
−40° to 288°C) hydraulic uids for advanced
aerospace applications. Lub Eng 38: 173–178, 1982.
3. Beane, G.A., IV et al. Military lubricants for aircraft turbine engines. Proceedings of 60th Meeting of
Structures and Materials Panel, AGARD, NATO, 1985.
4. Snyder, C.E., Jr. et al. Development of a shear stable viscosity index improver for use in hydrogenated
polyalphaole n-based uids. Lub Eng 42: 547–557, 1986.
5. Gschwender, L.J., C.E. Snyder Jr., G.A. Beane IV. Military aircraft 4 cSt gas turbine engine oil develop-
ment. Lub Eng 42: 654–659, 1987.
6. Gschwender, L.J. et al. Advanced high-temperature air force turbine engine oil program. In
W.R. Herguth, T.M. Warne, eds., Turbine Lubrication in the 21st Century, ASTM STP 1407.
West Conshohocken, PA: American Society for Testing and Materials, 2001.
7. Gschwender, L.J. et al. Improved additives for multiply alkylated cyclopentane-based lubricants. J. Syn.
Lub. 25: 31–41, 2008.
8. Gschwender, L.J. et al. Computational chemistry of soluble additives for per uoropolyalkylether liquid
lubricants. Trib Trans 39: 368–373, 1996.
9. Snyder, C.E., Jr. et al. Liquid lubricants and lubrication. In B. Bhushan, ed., CRC Handbook of Modern
Tribology, Vol. I. Boca Raton, FL: CRC Press, 2000, pp. 361–382.
10. Hellman, P.T., L. Gschwender, C.E. Snyder Jr. A review of the effect of metals on the thermo-oxidative
stability of per uoropolyalkylether lubricants, J Syn Lub 23: 197–210, 2006.
11. Hellman, P.T., J.S. Zabinski, L. Gschwender, C.E. Snyder Jr., A.L. Korenyi-Both. The effect of hard
coated metals on the thermo-oxidative stability of a branched per uoropolyalkylether lubricant. J Syn
Lub 24: 1–18, 2007.
CRC_59645_Ch025.indd 644CRC_59645_Ch025.indd 644 10/21/2008 2:24:42 PM10/21/2008 2:24:42 PM
Long-Term Additive Trends in Aerospace Applications 645
12. Liang, J., B. Cavdar, S.K. Sharma. A study of boundary lubrication thin lms produced from a per uo-
roplyalkylether uid on M-50 surfaces. I. Film species characterization and mapping studies. Trib Lett
3: 107–112, 1997.
13. Jensen, R.K. et al., Initiation in hydrocarbon autoxidation at elevated temperatures, Int J Chem Kinet 22:
1095–1107, 1990.
14. Sharma, S.K., N. Forster, L.J. Gschwender. Effect of viscosity index improvers on the elastohydrody-
namic lubrication characteristics of a chlorotri uoroethylene and a polyalphaole n uid. Trib Trans 36:
555–564, 1993.
15. Jones, W.R. et al. The tribological properties of several silahydrocarbons for use in space mechanisms.
NASA/TM–2001–211196, November 2001.
16. Gschwender, L.J., C.E. Snyder Jr., G.W. Fultz. Soluble additives for per uoropolyalkylethers liquid
lubricants. Lub Eng 49: 702–708, 1993.
17. Helmick, L.S. et al. The effect of humidity on the wear behavior of bearing steels with R
f
O(n–C
3
F
6
O)
x
R
f
per uoropolyalkylether uids and formulations. Trib Trans 40: 393–402, 1997.
18. Sharma, S.K., L.J. Gschwender, C.E. Snyder Jr. Development of a soluble lubricity additive for per uo-
ropolyalkylether uids. J Syn Lub 7: 15–23, 1990.
19. Tamborski, C., C.E. Snyder Jr. Per uoroalkylether substituted aryl phosphines and their synthesis, U.S.
Patent 4,011,267, March 1977.
20. MIL-PRF-5606H, Military speci cation, hydraulic uid, petroleum base; aircraft, missile and ordnance,
June 7, 2002.
21. MIL-PRF-83282D, Performance speci cation, hydraulic uid, re resistant, synthetic hydrocarbon
base, metric. NATO Code Number 537, September 30, 1997.
22. MIL-PRF-87257, Military speci cation, hydraulic uid, re resistant; low temperature synthetic hydro-
carbon base, aircraft and missile, December 8, 1997.
23. AS1241, Fire resistant phosphate ester hydraulic uid for aircraft, SAE, 1992.
24. MIL-H-53119, Military speci cation, hydraulic uid, non ammable, chlorotri uoroethylene base,
March 1, 1991.
25. Hoo, J.J.C., W.B. Green, eds. Bearing Steels: Into the 21st Century, ASTM STP 1327. West Con-
shohocken, PA, American Society for Testing and Materials, 1998.
26. Rai, A.K. et al. Performance evaluation of some pennzane-based greases for space applications.
Published in the 33rd Aerospace Mechanisms Symposium Proceedings, NAS/CP-1999-209259, 1999,
pp. 213–220.
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647
26
Eco Requirements for
Lubricant Additives
Tassilo Habereder, Danielle Moore, and Matthias Lang
CONTENTS
26.1 Biolubricants .......................................................................................................................647
26.2 Drivers for the Use of Biolubricants ...................................................................................649
26.2.1 Legislation .............................................................................................................649
26.2.2 Market Introduction Programs ..............................................................................650
26.2.3 National or International Labeling Schemes .........................................................650
26.2.3.1 German Blue Angel .............................................................................. 651
26.2.3.2 Swedish Standard ................................................................................. 652
26.2.3.3 Nordic Swan ......................................................................................... 652
26.2.3.4 Canadian Eco-Label—EcoLogo
M
........................................................ 654
26.2.3.5 European Eco-Label .............................................................................654
26.3 Base Fluids for Biolubricants .............................................................................................. 656
26.3.1 Triglycerides ..........................................................................................................657
26.3.2 Synthetic Esters ..................................................................................................... 657
26.3.3 Polyglycols .............................................................................................................658
26.3.4 Polyalphaole ns .....................................................................................................658
26.4 Additives for Biolubricants ................................................................................................. 659
26.4.1 Antioxidants ..........................................................................................................660
26.4.2 Metal Deactivators ................................................................................................ 661
26.4.3 Corrosion Inhibitors .............................................................................................. 661
26.4.4 Extreme-Pressure and Antiwear Additives ...........................................................662
26.4.5 Pour Point Depressants and Viscosity Index Improvers .......................................662
26.4.6 Antihydrolysis Agents ...........................................................................................663
26.4.7 Antifoam Agents, Demulsi ers, and Emulsi ers ..................................................663
26.5 Summary .............................................................................................................................663
References ......................................................................................................................................664
26.1 BIOLUBRICANTS
Amidst increasing public awareness, the Intergovernmental Panel on Climate Change (IPCC) has
recently nalized its Fourth Assessment Report “Climate Change 2007.” The report states that it
is very likely that human activities are the main cause of global warming in the past 50 years. One
reason for this is that global greenhouse gas (GHG) emissions have grown since preindustrial times,
with an increase of 70% between 1970 and 2004 [1].
Tribology by nature can play an important role in the reduction of greenhouse gas emissions.
The use of a suitable lubricant to reduce friction and prevent wear decreases the necessary energy
consumption and therefore has a direct impact on greenhouse gas emissions. In this sense, every
lubricant could be considered as environmentally friendly or as a biolubricant. This signi es how
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648 Lubricant Additives: Chemistry and Applications
dif cult it is to de ne the term biolubricant and is the only reason why there is not a single, generally
accepted de nition by the industry or by legislation. Biolubricants therefore tend to be characterized
by soft descriptions such as environmentally friendly, environmentally acceptable, environmentally
suitable, or more concrete claims such as possessing a high degree of biodegradability, produced
from renewable sources, and having a reasonable ecological and toxicological pro le.
The use of biodegradable and ecologically acceptable lubricants has traditionally been more
prevalent in industries such as agriculture, forestry, water treatment, and water management and in
areas of environmental interest such as national parks, tourist areas, and waterways.
In regard to the greenhouse gas emissions, renewability of a lubricant is an important factor.
Making a lubricant from biologically produced carbon-containing materials rather than using min-
eral oils enables to reduce the amount of new carbon released into the atmosphere. For this reason,
the use of biobased lubricants has a positive impact on the environment.
Våg et al. [2] undertook a comparative life cycle assessment study into base oils used in the
manufacture of hydraulic uids and calculated that the energy consumption per functional unit
during the production of a mineral oil–based uid (45,000 MJ) is greater than that for a synthetic
ester (22,000 MJ).
The use of biobased material is also recommended to conserve the limited resources of mineral
oil. To quantify the term biobased, methods such as ASTM D 6866-4 [3] using radiocarbon and
isotope ratio mass spectrometry analysis to determine the biobased content are used.
However, the greenhouse gas balance might not be the most important impact of a lubricant for
the environment. According to literature reports, at present ∼50% of all lubricants sold worldwide
end up into the environment through total loss applications, spills, volatility, or various other ways
[4]. Estimates for the loss of hydraulic uids are as high as 70–80% [5,6]. These lubricants can
contaminate the soil, the surface- and groundwater, as well as the air. To protect the environment
against the pollution by lubricants, the best approach would be, of course, rst to prevent the loss
of the lubricant. If this is not possible, environmentally acceptable uids have to be used. Environ-
mentally acceptable or environmentally friendly lubricants are described as those that are rapidly
biodegradable, have a low ecotoxicity, and do not harm water. Of course, these uids could also
be biobased, but this is not mandatory—in principle, some products derived from petrochemicals
could achieve the aforementioned environmental criteria.
The situation is made even more complex by the fact that terms such as being biodegradable
are not described by one single de nition. Biodegradation can be measured in a number of ways
and is usually undertaken indirectly by the measurement of the amount of oxygen consumed or the
amount of carbon dioxide produced by microorganisms. Typically, tests according to the Organisa-
tion for Economic Co-operation and Development (OECD) are used, such as the following:
301: Ready Biodegradability
A: Dissolved Organic Carbon (DOC) Die-Away Test
B: CO
2
Evolution Test
C: Modi ed Ministry of International Trade and Industry (MITI), Japan Test (I)
D: Closed Bottle Test
E: Modi ed OECD Screening Test
F: Manometric Respirometry Test
302A: Inherent Biodegradability: Modi ed Semi-continuous Activated Sludge (SCAS) Test
302B: Inherent Biodegradability: Zahn-Wellens/Eidgenössische Materialprüfungs-und
Versuchsanstalt für Industrie, Bauwesen und Gewerbe (EMPA) Test
302C: Inherent Biodegradability: Modi ed MITI Test (II)
303: Simulation Test—Aerobic Sewage Treatment
A: Activated
B: Bio lms
304A: Inherent Biodegradability in Soil
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Eco Requirements for Lubricant Additives 649
305: Bioconcentration: Flow-through Fish Test
306: Biodegradability in Seawater
307: Aerobic and Anaerobic Transformation in Soil
308: Aerobic and Anaerobic Transformation in Aquatic Sediment Systems
309: Aerobic Mineralization in Surface Water—Simulation Biodegradation Test
310: Ready Biodegradability—CO
2
in Sealed Vessels (Headspace Test)
311: Anaerobic Biodegradation of Organic Compounds in Digested Sludge—Method by
Measurement of Gas Production
312: Leaching in Soil Columns [7]
The determination of the ecotoxicity is normally based on the extrapolation of results obtained for
aquatic organisms (algae, daphnia, and sh) using de ned assessment factors. Such an evaluation
results in a concentration limit. A tested substance is then believed to have no negative impact on
an ecosystem, as long as the concentration of the substance is below the set limit. Additionally, in
some countries such as Germany, the so-called water hazard classes exist [8]. According to their
potential for being hazardous to waters, substances are classi ed into three different categories:
from class 1 (water hazardous class, WGK 1 = slightly hazardous to water) to class 3 (WGK 3 =
severely hazardous to water) [9].
With different de nitions applicable for a biolubricant, it is important to clarify the exact
requirements and speci cations to be met before starting to formulate such a uid. A good bio-
lubricant must not only comply with the environmental requirements but also has to meet neces-
sary technical requirements for the intended application. Ideally, a biolubricant should have at
least the same technical performance compared with a mineral oil–based uid and should meet
all relevant original equipment manufacturer (OEM) speci cations and national and interna-
tional norms.
26.2 DRIVERS FOR THE USE OF BIOLUBRICANTS
For many years, the raw materials for biolubricants have been relatively expensive compared with
mineral-based uids. Moreover, the rst generation of biolubricants was found to be de cient in
performance and acquired a poor reputation among end users. As cost and performance have been,
and still are, the major market drivers for lubricants, the success of biolubricants in the market was
retarded. On the contrary, many politically motivated initiatives have been undertaken to increase
the market share of environmentally friendly lubricants. These initiatives have become one of the
dominant market drivers for biolubricants. In general, these biolubricant initiatives can be roughly
distinguished into three main groups: legislation, market introduction programs, and national or
international labeling schemes.
26.2.1 LEGISLATION
With legislation, government regulates the use of certain ingredients positively or negatively—
either there is an obligation or mandate to use special components or a ban on some ingredients
or chemical classes. To enforce the use of biolubricants by law, however, is still somewhat of an
exception, more common being the obligation to use. The rst obligation to use biodegradable
lubricants was mandated in Portugal in 1991 [10]. This obligation required for outboard two-stroke
engine oils a degree of biodegradability of 66% (according to CEC-L-33-T-82 [11]), but stopped
short of further specifying the base uid to be used. Austria made another approach in 1992, when
it banned mineral oil–based chainsaw oils and mandated to end users the use of oils that are at least
90% biodegradable [12]. In Sweden, the Swedish Standard is mandatory, for example, for hydraulic
equipment in forestry application [13]. As the Swedish Standard also provides a labeling scheme, it
will be described in more detail in Section 26.2.3.2.
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650 Lubricant Additives: Chemistry and Applications
26.2.2 MARKET INTRODUCTION PROGRAMS
To promote the use of biolubricants, governments introduce programs in which, for example, the
expenses for the oil itself and the labor costs required to change to biolubricants, are subsidized. A
successful establishment of such market introduction programs has taken place in Germany (German
MIP Biobased Fuels and Lubricants [14]). The current funding to the market introduction program
(MIP) in Germany equates to ∼10 million euros every year [15]. In the framework of this program, the
government attempts to negate the price difference between mineral bases and biobased lubricants,
with end users being able to apply for funds to compensate for the additional costs. Lubricants eligible
for this program—of which qualifying categories are hydraulic uids, multifunctional oils, gear oils,
engine oils, and total loss lubricants—are declared on a positive list [14]. Qualifying lubricants on the
positive list must be made at least from 50% of renewable resources, being at least 60% readily bio-
degradable according to OECD 301 B, C, D, or F, and as ecotoxicological criteria, a classi cation of
WGK 1 (low hazardous to water) is required. According to H. Theissen, ∼90% of the subventions are
requested for applications in hydraulic equipment (H. Theissen, Personal Information).
In the United States, the U.S. Farm Bill [16] has been introduced to strengthen the farm econ-
omy over the long term [16], the main focus of which is to ensure a high degree of renewability of
used components. In the United States, a biobased product describes a commercial or industrial
product (other than food or feed) that is composed, in whole or in signi cant part, of biological
products or renewable domestic agricultural materials (including plant, animal, and marine materi-
als), or forestry materials [17].
The American program requires differing biobased content, depending on the application [18,19]:
Mobile equipment hydraulic uids: 44%
Penetrating lubricants: 68%
Cutting, drilling, and tapping oils: 64%
Firearm lubricants: 49%
To support the use of ecological products and services, the U.S. government also passed the Federal
Bio-based Product Preferred Procurement Program
[20], also known as FB4P [20], which creates
a federal market for biobased products. This type of green procurement requires federal agencies
to buy preferentially biobased products, provided the same technical performance can be achieved
in comparison with conventional products. A test tool was developed, called Building for Environ-
mental and Economic Sustainability (BEES [21]), which measures environmental performance,
economic performance, and human health aspects. BEES also provides a computer program [22],
which will calculate a score to aid selection of the correct biolubricant, as shown in Figure 26.1.
Aspects such as aquatic toxicity, content of dangerous components, CO
2
balance, and life cycle
analysis are also considered using BEES.
In the BEES calculation model, the environmental performance score results from a combina-
tion of product performances, across 12 different environmental impacts on a single score—the
lower the score, the better is the product’s overall environmental performance. BEES scores eco-
nomic performance on the basis of a product’s life cycle cost—all cost from purchase to disposal.
The lower the life cycle cost, the better is the product’s overall economic performance [23].
The United States currently does not have a biobased product labeling program, in the sense
of being awarded with a special label (Jessica Riedl, Center for Industrial Research and Service
(CIRAS), Private Communication, e-mail, July 3, 2007).
26.2.3 NATIONAL OR INTERNATIONAL LABELING SCHEMES
Companies can apply at different, mostly nongovernmental, organizations to have their products
and services certi ed with a specially created label for environmental friendly lubricants (European
Eco-label, German Blue Angel, Nordic Swan, Swedish Standard, etc.). The labeling schemes are not
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Eco Requirements for Lubricant Additives 651
intended to grant subsidies, but to provide a commonly recognized promotional tool and to increase
public awareness and create sensitivity for environmentally friendly products and services. Cur-
rently, several such labels exist worldwide.
26.2.3.1 German Blue Angel
The general Blue Angel label was founded in 1977/1978 [24], and the rst voluntary environmen-
tal standard speci cally for lubricants (RAL-UZ 48 [25]) came into effect in 1988. The German
Eco-label Blue Angel now contains three standards for the use of lubricants:
RAL-UZ 48 Readily Biodegradable Chain Lubricants for Power Saws [25]
RAL-UZ 64 Readily Biodegradable Lubricants and Forming Oils [26]
RAL-UZ 79 Readily Biodegradable Hydraulic Fluids [27]
According to VDMA 24568 [28], not only technical performance requirements, but also the environ-
mental effect of the used lubricants play an important role. As can be deduced from the naming of the
standards or norms, biodegradability plays an important role for this label. For example, hydraulic
uids must have a biodegradability of 70% according to OECD 301—B, C, D, or F [27]. In addition,
hydraulic uids must not contain among others, any substances that are listed in Annex I to Direc-
tive 67/548/EEC [29] and that are classi ed according to Section 4a, Gefahrstoffverordnung [30]
(Ordinance on Hazardous Substances) as very toxic (T+) or toxic (T) and which according to Annexes
III and VI to Directive 67/548/EEC have to be marked with the following risk phrases: R 45 (may
cause cancer), R 46 (may cause heritable genetic damage), R 48 (danger of serious damage to health
by prolonged exposure), and R 68 (possible risk of irreversible effects). Furthermore, they must not
be water-hazardous (Water Hazard Class 3). An additional point is that the German label explicitly
includes technical performance requirements. To be awarded, the hydraulic uids are required to
ful ll at least the minimum technical requirements under ISO 15380 [29,31].
Indoor air quality
Habitat alteration
Water intake
Critical air pollutants
Human health
Smog
Ozone depletion
Ecological toxicity
First cost
Future costs
Economic performance score
Environmental performance score
Overall score
Carbon dioxide
Methane
Nitrous oxide
Global warming
Acidification
Eutrophication
Fossil fuel depletion
FIGURE 26.1 Impacts on environmental and economic performance score. (Based on http://www.bfrl.nist.
gov/oae/software/bees/model.html.)
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652 Lubricant Additives: Chemistry and Applications
Broadly, this German Eco-label focuses on aquatic toxicity, biodegradation, bioaccumulation,
content of dangerous components, and technical performance for the different categories of lubri-
cants. Other characteristics such as renewability, CO
2
balance, or life cycle analysis are not con-
sidered in detail. Nevertheless, it can be stated that the Blue Angel requirements are much harsher
than the requirements of the German Market Introduction Program. This can also be derived from
the fact that only 14% of the lubricants currently listed on the MIP positive list also bear the Blue
Angel label.
26.2.3.2 Swedish Standard
The Swedish standard [13] has been developed from a starting point of an environmental project
in the city of Gothenburg [32]. Since then, two standards—SS 155434 for hydraulic uids and
SS 155470 for greases—have been put into place. The environmental requirements in both stan-
dards are focused on individual chemical substances regarding sensitizing properties, acute
toxicity, and biodegradability [33]. The Swedish standard SS 155434 is a legal requirement for
hydraulic equipment in forestry application. Version 4 of SS 155434, which came into effect in
July 2000, introduced new and more stringent ecological requirements. Depending on the appli-
cable method, the biodegradability of the base uid must meet at least 60% (ISO 9439 [34], ISO
9408 [35], ISO 10707 [36], ISO 10708 [37]) or more than 70% (ISO 7827 [38]). The biodegrad-
ability of the oil and the toxicity of the oils and the additives are considered. To be awarded with
this label, technical application requirements—that is, to offer nearly the same performance as
mineral oil–based lubricants—must be ful lled. According to Willing [39], only products that
are listed on a positive list and then automatically ful ll diverse requirements are allowed to be
marketed. In addition, in certain Scandinavian countries, a tax exemption on biolubricants is in
place [40].
26.2.3.3 Nordic Swan
Another well-known European Eco-label is the Nordic Swan [41], which is awarded by Norway,
Sweden, Finland, Iceland, and Denmark. These countries decided to introduce a neutral, inde-
pendent, and the world’s rst multinational label with the intention of assisting consumers in the
selection of environmentally friendly and nonhazardous products (see Ref. 42, p. 139). Beginning
in the late 1970s, the rst biodegradable outboard marine engine oils were developed for the Scan-
dinavian and the North American markets, for use not only in boats but also in snowmobiles and
golf carts.
The Nordic Swan itself was introduced as a voluntary Eco-label in 1989 and can be awarded for
chain oil, mold oil, hydraulic oil, two-stroke oil, lubricating grease, metal cutting uid, and trans-
mission/gear oil. For chain oils, mold oils, hydraulic oils, lubricating greases, and two-stroke oils, a
certain percentage of renewable raw materials is imposed.
As base uids, virgin mineral oil, white oil, severely hydrotreated oil, synthetic oil, synthetic
esters, polyalphaole ns (PAO), dibasic acid esters, polyol esters, alkylated aromatics, polyalkylene
glycols, phosphate esters, vegetable oil, animal oil, and re-re ned mineral oil, as well as mixtures
of these oils are all potential options.
“The eco-labelling criteria acknowledge that lubricating oils must function satisfactorily and
that for this purpose, some lubricant types might need to contain higher levels of potentially haz-
ardous components” [43]. Conversely, products labeled with the Nordic Swan are not allowed to
represent a hazard to the environment or to the health, must function satisfactorily, and must have a
minimum content of renewable resources. The requirements are listed in Table 26.1.
In accordance with OECD 201 and 202 or equivalent methods, aquatic toxicity must be mea-
sured [7]. Short- and medium-chained chloroparaf ns and alkylphenoletoxylates and other known
endocrine disrupters must not be present in the product. Aerosol products must not contain halogen
hydrocarbon [43].
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Eco Requirements for Lubricant Additives 653
TABLE 26.1
Environmental Criteria by Type of Lubricating Oil to Meet Nordic Swan Requirements
Amount of Renewable
Substances in the
Product (%)
Amount of Refi ned
Substances in the
Product
Base Oil Fulfi lling
R50, R51/53, R52/53,
R53 (%)
Additives Classifi ed with
Risk Phrase R50 or
R50/53 (%)
Additives Classifi ed
with Risk Phrase
R51/53 (%)
Additives Classifi ed
with Risk Phrase
R52/53 or R53 (%)
Chain oil Minimum 85 No requirement 0.0 Maximum 1.0 Maximum 1.0 Maximum 3.0
Mold oil Minimum 85 No requirement 0.0 Maximum 1.0 Maximum 1.0 Maximum 3.0
Hydraulic oil Minimum 65 No requirement 0.0 Maximum 2.0 Maximum 1.0 Maximum 3.0
Lubricating grease Minimum 65 No requirement 0.0 Maximum 1.0 Maximum 1.0 Maximum 2.0
Two-stroke oil Minimum 50 No requirement 0.0 Maximum 1.0 Maximum 1.0 Maximum 15
Metal cutting uid Minimum 65 or
minimum 65%
0.0 Maximum 2.0 Maximum 2.0 Maximum 5.0
Gear/transmission uid Minimum 65 or
minimum 65%
No requirement No requirement No requirement No requirement
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