United States Environmental Protection Agency

Office of Wastewater Management

Washington, DC 20460

EPA 800‐R‐11‐002

November 2011

Environmentally Acceptable

Lubricants
Exhaust Gas Scrubber Washwater Effluent Contents

ii 

CONTENTS 

Page 

1 INTRODUCTION .................................................................................................................... 1

1.1 Marketing and Labeling .......................................................................................... 3

2 TYPES OF ENVIRONMENTALLY ACCEPTABLE LUBRICANTS .................................................. 4

2.1 Vegetable Oils ......................................................................................................... 4

2.2 Synthetic Esters ....................................................................................................... 4

2.3 Polyalkylene Glycols .............................................................................................. 5

2.4 Water ....................................................................................................................... 5

3 CONSIDERATIONS FOR EALS IN THE AQUATIC ENVIRONMENT ............................................ 6

3.1 Thickening Agents .................................................................................................. 6

3.2 Advantages and Disadvantages of Vegetable-based EALs .................................... 6

3.3 Advantages and Disadvantages of Synthetic Ester-based EALs ............................ 7

3.4 Advantages and Disadvantages of Polyalkylene Glycol-Based EALs ................... 8

3.5 Availability and Cost of EALs ................................................................................ 8

4 DEFINING “ENVIRONMENTALLY ACCEPTABLE” ................................................................. 10

4.1 Biodegradability .................................................................................................... 10

4.2 Aquatic Toxicity ................................................................................................... 11

4.3 Bioaccumulation ................................................................................................... 13

4.4 Summary of Environmentally Acceptable Lubricant Characteristics .................. 14

5 ENVIRONMENTALLY ACCEPTABLE LUBRICANT LABELING PROGRAM ............................... 16

5.1 National Labeling Programs ................................................................................. 16

5.1.1 Blue Angel ................................................................................................ 16

5.1.2 Swedish Standard ...................................................................................... 16

5.2 International Labeling Programs........................................................................... 17

5.2.1 Nordic Swan.............................................................................................. 17

5.2.2 European Eco-label ................................................................................... 17

5.2.3 OSPAR ...................................................................................................... 19

5.3 Summary of Environmentally Acceptable Lubricant Labeling Programs ............ 19

6 CONCLUSION ...................................................................................................................... 21

7 REFERENCES ................................................................................................................... 7-22
Environmentally Acceptable Lubricants 

iii 

LIST OF TABLES 

Page 

1 Cost of EALs........................................................................................................................9

2 Internationally Standardized Test Methods for Measuring Biodegradability ....................11

3 Summary of Differential Biodegradation Rates by Lubricant Base Oils ..........................11

4 OECD Aquatic Toxicity Tests ...........................................................................................12

5 Summary of Comparative Toxicity of Base Oils ...............................................................12

6 Summary of Bioaccumulation Potential by Base Oil Types .............................................14

7 Comparative Environmental Behavior of Lubricants by Base Oil Type ...........................15

8 Comparison of EAL Labeling Programs ...........................................................................20

LIST OF FIGURES 

Page 

1 Annual Oil Inputs into the Marine Environment .................................................................2

The EPA contacts for this document are Ryan Albert (202) 564-0763 and Brian Rappoli (202) 

566-1548. 
Environmentally Acceptable Lubricants Section 1 - Introduction

1 

SECTION 1 

INTRODUCTION 

The purpose of this document is to describe the range of environmentally preferable 

lubricants that may be used as a best management practice (BMP) by operators of vessels 

covered under the Vessel General Permit for Discharges Incidental to the Normal Operation of 

Vessels (VGP)1

. Within this document, the term environmentally acceptable lubricant (EAL) is 

used to describe those lubricants that have been demonstrated to meet standards for 

biodegradability, toxicity and bioaccumulation potential that minimize their likely adverse 

consequences in the aquatic environment, compared to conventional lubricants. In contrast, 

lubricants that may be expected to have desirable environmental qualities, but have not been 

demonstrated to meet these standards, are referred to as environmentally friendly lubricants 

(EFLs) or biolubricants. 

Lubricants lost from a vessel enter the aquatic environment, where serious damage to the 

aquatic ecosystem can occur. Consequently, there has been an emphasis on encouraging the use 

of EALs on vessels to protect the environment (Carter, 2009). Although their use is increasing, 

EALs comprise only a small percentage of the total lubricant market. 

The significance of lubricant discharges (not accidental spills) to the aquatic ecosystem is 

substantial. The majority of ocean going ships operate with oil-lubricated stern tubes and use 

lubricating oils in a large number of applications in on-deck and underwater (submerged) 

machinery. Oil leakage from stern tubes, once considered a part of normal “operational 

consumption” of oil, has become an issue of concern and is now considered as oil pollution. 

Stern tube leakage is a significant source of lubricant oil inputs to the aquatic environment. A 

2001 study commissioned by the European Commission DG Joint Research Centre revealed that 

routine unauthorized operational discharges of oil from ships in the Mediterranean Sea created 

more pollution than accidental spills (Pavlakis et al., 2001). Stern tube leakage was identified as 

a major source of these discharges. 

An analysis of data on oil consumption performed by a lubricant supplier indicated a 

range of average daily stern tube lubricant consumption rates for different vessels (Etkin, 2010). 

The average rate across vessel types was 2.6 liters per day, but ranged from less than 1 liter per 

day to 20 liters per day. Because it is common practice to use the lubricant supplied for the 

vessel’s main engines as the stern tube lubricant to minimize the number of lubricants held on 

board, the amount which is used in stern tubes and released to the sea is not recorded. 

Engine oil formulations have the correct characteristics (e.g., viscosity) to fulfill the role 

of lubricants specifically formulated for stern tubes. However, engine oil additives, which can be 

up to 30% of the formulation, are strongly alkaline (to neutralize the acids formed during fuel 

combustion). Consequently, due to the nature of engine oil additives, this practice greatly 

increases the toxic effects of stern tube discharges. 

 

1

 The 2008 VGP encourages vessel owners and operators to use environmentally preferable lubricants whenever 

possible. 
Environmentally Acceptable Lubricants Section 1 - Introduction

2 

In addition to spills and stern tube leakage, there are “operational inputs” of lubricant oils 

that occur due to continuous low-level discharges and leakages that occur during normal vessel 

operations in port. The sources of operational discharges include deck machinery and in-water 

(submerged) machinery. There are a number of systems situated below the waterline that must be 

lubricated. The main systems to consider are the stern tube bearing, thruster gearboxes, and 

horizontal stabilizers. All of these have pressurized lubricating oil systems that maintain a 

pressure higher than the surrounding sea. This ensures that no significant amount of seawater can 

enter the oil system, where it would compromise the unit’s reliability. However, any leakage of 

lubricant oil flows into the sea. 

A 2010 study estimated the marine inputs of lubricant oils within the 4,708 ports and 

harbors of the world through stern tube leakage and operational discharges from marine shipping 

(Etkin, 2010). The study results indicate that commercial vessels make over 1.7 million port 

visits each year and leak 4.6 to 28.6 million liters of lubricating oil from stern tubes. In addition, 

32.3 million liters of oil is introduced to marine waters from other operational discharges and 

leaks. In total, operational discharges (including stern tube leakage) input 36.9 to 61 million 

liters of lubricating oil into marine port waters annually – the equivalent of about one and a half 

Exxon Valdez-sized spills. Assuming that the higher estimate of stern tube leakage is 

representative of the inputs that may occur in port as well as in transit, the total estimated input 

of lubricating oil from leakage and operational discharges represents nearly 61 million liters 

annually worldwide. Leaks of lubricating oil represent 10 percent of the total oil inputs into 

marine waters, as estimated in the 2003 NRC Oil in the Sea study (see Figure 1). The total 

annual estimated response and damage costs for these leaks and operational discharges are 

estimated to be about $322 million worldwide. Total estimated costs for the U.S. are estimated to 

be $31 million annually (Etkin, 2010). 

Based on Etkin, 2010 and NRC, 2003 

Figure 1. Annual Oil Inputs into the Marine Environment 

The following sections of this document describe the main types of EALs in current 

production; considerations for EALs in the aquatic environment; the standards for 

biodegradability, toxicity and bioaccumulation potential of EALs; the potential advantages and 

disadvantages of using EALs on board commercial vessels; and labeling programs. 
Environmentally Acceptable Lubricants Section 1 - Introduction

3 

1.1 MARKETING AND LABELING

Although EALs have been in commercial production for years, they comprise a small 

portion of the total lubricant market and are still regarded as niche products (Habereder et al., 

2008). The market for EALs continues to expand, particularly in Europe, where the use of such 

lubricants is being encouraged through a combination of tax breaks, purchasing subsidies, and 

national and international labeling programs based on well-defined criteria. Many lubricants are 

advertised as being environmentally preferable; however, currently there are no regulatory 

standards for EALs, and no internationally accepted term by which they are defined. To 

distinguish lubricants which have been shown to be both biodegradable and non-toxic according 

to acceptable test methods from those lubricants that are simply marketed as being 

“environmental” (or similar terminology), in their 1999 Lubricants and Hydraulic Fluids Manual, 

the US Army Corps of Engineers recommended use of the term “environmentally acceptable” (a 

term commonly used by American Society for Testing and Materials (ASTM) committees) to 

address environmental lubricants. Bioaccumulation potential was not addressed within this 

definition of EALs. 

While numerous terms are presently used to advertise lubricants as having desirable 

environmental properties, there is growing consensus to use the term “environmentally 

acceptable” to denote a lubricant that is biodegradable, exhibits low toxicity to aquatic organisms 

and has a low potential for bioaccumulation. Although many tests for these qualities exist, there 

is also harmonization underway within the lubricant manufacturing community regarding the 

most appropriate standard testing methods for these and other qualities determined to be 

important for an EAL, such as the proportion of renewable (recyclable) materials used in 

manufacturing. An environmentally acceptable lubricant should still perform well in comparison 

to the conventional lubricant it replaces. This harmonization is being driven by national and 

international labeling programs, particularly in European nations where the testing procedures 

and criteria have been codified (Habereder et al., 2008 and IENICA, 2004). These labeling 

requirements, while not regulated by law, have helped to clarify the difference between EAL and 

EFL products in the marketplace. 

Because the majority of a lubricant is composed of the base oil, the base oil used in an 

EAL must be biodegradable. The three most common categories of biodegradable base oils are: 

1) vegetable oils, 2) synthetic esters, and 3) polyalkylene glycols. Due to the low toxicities of 

these three types of base oils, aquatic toxicity exhibited by lubricants formulated from them is 

typically a consequence of the performance enhancing additives or thickening agents (found in 

greases) used in the formulation, which can vary widely. 
Environmentally Acceptable Lubricants Section 2- Types of Environmentally Acceptable Lubricants

4 

SECTION 2 

TYPES OF ENVIRONMENTALLY ACCEPTABLE LUBRICANTS 

Environmentally acceptable lubricants are commonly classified according to the type of 

base oil used in their formulation. In general, lubricants consist of approximately 75 to 90 

percent base oil. Greases contain approximately 10 percent thickening agent, which is usually a 

soap (Gow, 2009), in addition to the base oil. The remaining fraction of a lubricant formulation 

consists of performance enhancing additives. A lubricant formulation can include hundreds of 

additives, which address performance issues specific to their application and performance 

shortcomings of the base oil. Additives are commonly used to address oxidative aging, corrosion, 

high pressure, low or high temperature conditions, phase transition, shear, foaming, and 

hydrolysis (particularly for vegetable and synthetic ester-based oils) (Habereder et al., 2008). 

The number of additives that are compatible with vegetable oils, synthetic esters, or 

polyalkylene glycols is small relative to the number of additives that are compatible with 

conventional (mineral) base oils. However, this is changing as a result of increased emphasis on 

EAL development. Additive manufacturers are working more closely with the lubricant industry 

to design additives that are suitable for improving the performance of EALs that are more 

environmentally benign (Aluyor et al. 2009). For some of the more stringent labeling programs 

(see Section 5), additives used in EAL must be both ashless (i.e., containing no metals other than 

Ca, Na, K, Mg) and non-toxic (Haberader et al. 2009). Among the soaps, calcium-based soaps 

are considered less toxic compared to other types (e.g., lithum-based), and soaps in general are 

considered less toxic than graphite thickeners (Gow, 2009). 

2.1 VEGETABLE OILS

The main components of vegetable oils are triglycerides (natural esters), the precise 

chemical nature of which is dependent on both the plant species and strain from which the oil is 

obtained (Haberader et al., 2008 and Nelson, 2000). Outside the U.S., rapeseed is the most 

commonly used crop for creating vegetable oil lubricants (Cuevas, 2005 and Habereder et al., 

2008). In the U.S., the most commonly used crops for producing vegetable oil lubricants are 

canola, soybeans, and sunflowers (Nelson, 2000). 

Largely because of performance issues related to low thermo-oxidative stability and poor 

cold flow behavior, pure vegetable oil-based lubricants comprise a relatively small fraction of the 

biolubricant market, although recent research developments have shown promise for overcoming 

these shortcomings (Erhan et al., 2006 and Kabir et al., 2008). Another reason is that vegetable 

oil-based lubricants are much less available than synthetic esters (Bremmer and Plonsker, 2008). 

To date, their most common commercial applications include hydraulic fluid and wire rope 

grease. 

2.2 SYNTHETIC ESTERS

Lubricants based on synthetic esters have been in production longer than any other class 

of biolubricant and were first used for jet engine lubrication in the 1950s. Synthetic esters can be 

prepared by the esterification of biobased materials (i.e., some combination of modified animal 

fat and vegetable oil). Because synthetic esters can be specifically tailored for their intended 
Environmentally Acceptable Lubricants Section 2- Types of Environmentally Acceptable Lubricants

5 

application, they have many performance advantages over pure vegetable oils, and are used as 

the base oil in lubricants for many vessel applications, including hydraulic oil, stern tube oil, 

thruster oil, gear lubricant, and grease (ACE, 1999 and Habereder et al., 2008). Synthetic estersbased EALs are developed and marketed by several major oil companies including British 

Petroleum, Chevron, Exxon/Mobil and Gulf, and are currently the most widely commercially 

available class of EAL. 

2.3 POLYALKYLENE GLYCOLS

Polyalkylene glycols (PAG) are synthetic lubricant base oils, typically made by the 

polymerization of ethylene or propylene oxide (Brown, 1997). Depending on the precursor, they 

can be soluble in either oil (propylene oxide) or water (ethylene oxide) (Greaves, 2008 and 

Habereder et al., 2008). Although they are made from petroleum-based materials, PAGs can be 

highly biodegradable, particularly the water soluble PAGs (Greaves, 2008; Sada et al., 2008; and 

Sada et al., 2009). 

2.4 WATER

At least one company has developed a completely seawater-lubricated stern tube system 

that uses non-metallic bearings in place of metal bearings. This system is currently in place in 

over 500 commercial vessels, including several Carnival Corporation cruise ships (Carter, 2009). 
Environmentally Acceptable Lubricants Section 3- Considerations for EALs in the Aquatic Environment

6 

SECTION 3 

CONSIDERATIONS FOR EALS IN THE AQUATIC 

ENVIRONMENT 

A number of factors must be considered when selecting lubricants for use in the aquatic 

environment. Vessels require a variety of lubricants for different applications and on-ship storage 

can be limited. Consequently, the most useful lubricants are those that can perform well in a 

variety of applications (Rana, 2001). Additionally, lubricants must be widely available; in the 

case of some larger ocean going vessels, compatible lubricants must be available at ports around 

the globe (Blanken, 2006). 

Marine environments are characterized by high humidity conditions, and seawater ingress 

can pose serious lubrication problems in sealed compartments, such as stern tubes and hydraulic 

systems (Rana, 2001). Stern tube seals are highly susceptible to leakage, both from normal 

operations, including vibrations and misalignment, and from contact with nets or fishing lines 

(Sada et al., 2008 and Carter, 2009). The constant presence of seawater increases the potential 

for corrosion, requiring thicker greases to repel water and corrosion inhibitors to minimize 

corrosion following seawater ingress. In addition, lubricants subject to frequent contact with 

water have a greater likelihood of undergoing some degree of biodegradation (ACE, 1999).

3.1 THICKENING AGENTS

Stiffer greases (i.e., National Lubricating Grease Institute grade 3 or higher) are typically 

used in marine applications as they repel water more effectively. Lithium-based thickeners are 

the most commonly used thickening agents, as they are considered to have the best all-purpose 

formulation. Although they comprise a much smaller fraction of the grease market, calciumbased thickeners do perform well under cool, wet conditions, and are used in formulations for 

some marine applications (e.g., propeller housing and water pumps). Anhydrous calcium-based 

greases are becoming increasingly common in Europe, where there is a greater emphasis on 

adoption of EALs, because of their relatively low toxicity and better performance at higher 

temperatures (Gow, 2009). 

3.2 ADVANTAGES AND DISADVANTAGES OF VEGETABLE-BASED EALS

In addition to their environmental benefits (i.e., high biodegradability and low aquatic 

toxicity), vegetable oils possess several advantageous performance qualities compared to mineral 

oils. They have a higher viscosity index (meaning they do not thin as readily at high 

temperatures) and they have a higher lubricity, or ability to reduce friction (Nelson, 2000; 

IENICA, 2004). Vegetable oil-based lubricants also have a high flash point, meaning they 

combust at higher temperatures than conventional mineral oils. They perform well at extreme 

pressures, and do not react with paints, seals, and varnishes (ACE, 1999). 

Vegetable oils possess several major performance drawbacks, however, which have 

limited their use in the formulation of EALs. The primary limitations are (1) poor performance at 

both low and high temperatures and (2) oxidative instability (Erhan et al., 2006 and Habereder et 

al., 2008). Vegetable oils thicken more than mineral oils at low temperatures and are subject to 
Environmentally Acceptable Lubricants Section 3- Considerations for EALs in the Aquatic Environment

7 

increased oxidation at high temperatures, resulting in the need for more frequent oil changes. 

These shortcomings can be addressed with the use of selected additives for a formulation or 

through the selective breeding and use of high-oleic oils (i.e., oils that contain more oleic acid, a 

monounsaturated fat, and less polyunsaturated fats) that are less susceptible to oxidative 

instability. The use of selected additives can increase production costs and may decrease the 

overall environmental acceptability of the product (Nelson, 2000; Bremmer and Plonsker, 2008). 

In addition, vegetable oils remove mineral oil deposits, resulting in the need for more frequent 

oil filter service. 

Vegetable oil lubricants are more expensive than comparable mineral oil lubricants, as a 

function of both higher base oil costs, as well as higher costs for the base oil-compatible 

additives (ACE, 1999). Although Miller (2008) stated that vegetable oil lubricants cost 

approximately double that of mineral base oils, more recent information obtained through 

personal communication with a major lubricant supplier suggests that the current cost premium 

for these biolubricants may be only 20% more. Changing from a mineral to a vegetable oil 

lubricant is relatively simple, as vegetable oils and mineral oils are compatible and vegetable oil 

lubricants will perform properly if some mineral oil residue remains. Because the overall 

formulations are less toxic, disposal costs are generally lower; however, this may not always be 

the case, as fewer disposal stations are able to accept spent biobased lubricants (ACE, 1999; 

Nelson, 2000; and Bremmer and Plonsker, 2008). 

3.3 ADVANTAGES AND DISADVANTAGES OF SYNTHETIC ESTER-BASED EALS

Synthetic esters perform well across a wide range of temperatures, have a high viscosity 

index, possess high lubricity, provide corrosion protection, and have high oxidative stability 

(ACE, 1999 and Habereder et al., 2008). Because they contain biobased material, many synthetic 

esters satisfy testing requirements for biodegradability and aquatic toxicity, although they tend to 

be less readily biodegradable than pure vegetable oil-based lubricants (WISE Solutions, 2006). 

Synthetic ester-based lubricants can be more or less toxic than vegetable oil-based lubricants, 

depending on the aquatic toxicity of the additives used in the formulation. The only notable 

performance issue with synthetic esters is that they are incompatible with some paints, finishes, 

and seal materials (ACE, 1999). 

Synthetic esters are generally the most expensive class of EAL (Miller, 2008). Synthetic 

ester-based biolubricants cost approximately 2-3 times that for comparable conventional mineral 

oil-based lubricants. As the availability of synthetic ester-based EALs increases, this cost 

differential is expected to decline. 

The relatively higher cost of synthetic esters is somewhat mitigated by their high 

oxidative stability, which results in longer lubricant life. This is particularly applicable to areas 

of the vessel that require more frequent lubricant changes (e.g., engine oil, hydraulic fluid, stern 

tube-thruster fluid). Synthetic esters are compatible with mineral oil, which reduces changeover 

costs, but similar to vegetable oils in that their effectiveness at removing mineral oil deposits can 

cause filters to clog during the period initially following lubricant changeover (ACE, 1999). 

Disposal costs are similar to those for vegetable oil-based lubricants. 
Environmentally Acceptable Lubricants Section 3- Considerations for EALs in the Aquatic Environment

8 

3.4 ADVANTAGES AND DISADVANTAGES OF POLYALKYLENE GLYCOL-BASED EALS

Lubricants consisting of polyalkylene glycols (PAGs) have the best overall low- and 

high-temperature viscosity performance among all of the classes of biolubricants. For marine 

applications, water soluble PAG EALs are attractive because, in addition to their high 

biodegradability, they retain their performance characteristics following water influx better than 

other EALs; as a result, PAG EALs have received consideration as a stern tube lubricant (Sada et 

al., 2008; Sada et al., 2009). The water solubility of ethylene oxide-derived PAGs can improve 

performance relative to other lubricants by maintaining viscosity following some fraction of 

water influx (up to 20% in some laboratory tests), which can be of great importance for stern 

tube lubrication (Sada et al., 2008; Carter, 2009). PAGs also perform well in terms of lubricity, 

viscosity index, and corrosion protection. The relatively high viscosity and lubricity of PAGs has 

resulted in the recent development of PAG-based thruster lubricants (Sada et al., 2009). 

Disadvantages associated with PAGs are that they are incompatible with mineral oils, as 

well as most paints, varnishes, and seals (ACE, 1999; Sura et al., 2008). Because of this 

incompatibility, they have the highest changeover costs of any class of EAL (Sada et al., 2008). 

Additionally, water soluble PAGs may demonstrate increased toxicity to aquatic organisms by 

directly entering the water column and sediments rather than remaining on the water column 

surface as a sheen (Habereder et al., 2008). 

3.5 AVAILABILITY AND COST OF EALS

At the present, the global availability of EALs for different marine applications is 

growing. One manufacturer of marine EALs, Castrol Bio Range, provided data demonstrating 

that stern tube and thruster lubricant, hydraulic fluids, gear lubricants and grease were available 

in the following global regions and countries (Pearce et al., 2010; Castrol Marine, 2011): 

 Americas: USA; 

 Northern Europe: Belgium, Denmark, Finland, France, Germany, Netherlands, 

Norway, Sweden, UK; 

 Mediterranean: Italy, Spain, Turkey, UAE; and 

 Asia-Pacific: China, Japan, Hong Kong, Singapore, Korea. 

Market cost data for EALs are unavailable, because manufacturers consider such data to 

be proprietary marking information. The purchase prices of EALs are guarded closely by the 

manufacturers, and EPA has generally been unable to obtain publicly available cost information 

from EAL manufacturers. Operating costs for ship-owners and charterers using environmentally 

preferable lubricants are expected to increase modestly relative to conventional products, 

although there can be efficiency gains from longer life (e.g., reduced corrosive properties, 

enhance water contamination performance). However, the benefit of using environmentally 

preferable lubricants can be considerable in terms of reduced environmental impacts. 

Some indication of the cost of EALs relative to conventional lubricants was provided by 

a major lubricant vendor and is tabulated in Table 1. Some specialized lubricants may have 

higher costs. 
Environmentally Acceptable Lubricants Section 3- Considerations for EALs in the Aquatic Environment

9 

Table 1. Cost of EALs 

Lubricant Base Oil 

Ratio of EAL cost to 

Conventional Mineral Oil 

Lubricant Cost 

Mineral Oil 1 

Vegetable Oils 1.2 

Synthetic Esters 2 to 3 

Polyalkylene Glycols 2 to 3 

An informal survey of websites for the boating supply distributors West Marine, 

Jamestown Distributors, Aerospace Lubricants, Inc. and Aqua Lube, demonstrates that semisynthetic ester and full synthetic ester engine oil, gear oil, and greases are the most commonly 

available biolubricants for recreational vessel owners. The costs of full synthetic ester 

formulations (primarily two cycle and four stroke engine oils) range from 1.4-1.8 times the costs 

of comparable conventional (mineral oil) formulations. These distributor websites do not provide 

information as to whether any of the synthetic ester-based biolubricants meet certification 

standards that would classify them as EAL. For commercial vessels, relative pricing information 

for Gulf Oil marine lubricants reveals that costs for biolubricants advertised (synthetic gear oil, 

compressor oil, and coolant oil, the three synthetic lubricants), ranged from approximately 1.3-

2.5 times (coolant oil) to 3.5-4.3 times (gear oil and compressor oil) the cost for comparable 

mineral oil products (Gulf Marine, 2010). It may be reasonable to assume that the cost premium 

for EALs is similar to these price ratios. 

Many countries, primarily in Europe, encourage the manufacture and consumption of 

EALs. Examples are through tax exemptions on environmentally acceptable base oils, taxes on 

mineral oils, subsidies to consumers to cover the price difference between conventional and 

EALs, or preferential purchasing programs that require a percentage of certain classes of product 

to be made from renewable resources (Habereder et al., 2008; IENICA, 2004; and WISE 

Solutions, 2006). 
Environmentally Acceptable Lubricants Section 4 - Defining “Environmentally Acceptable”

10 

SECTION 4 

DEFINING “ENVIRONMENTALLY ACCEPTABLE” 

Lubricants may be labeled using a variety of terms to signify that they are 

environmentally friendly. Although EFLs are most likely to be tested for biodegradability, 

aquatic toxicity and bioaccumulation potential, there are numerous other methods, which vary in 

their sensitivity. 

4.1 BIODEGRADABILITY

Biodegradability is a measure of the breakdown of a chemical (or a chemical mixture) by 

micro-organisms. Primary biodegradation is the loss of one or more active groups in a chemical 

compound that renders the compound inactive with regard to a particular function (Betton, 

2009). Primary biodegradation may result in the conversion of a toxic compound into a less toxic 

or non-toxic compound. Ultimate biodegradation, also referred to as mineralization, is the 

process whereby a chemical compound is converted to carbon dioxide, water, and mineral salts 

(Betton, 2009). 

In addition to primary and ultimate biodegradation, biodegradation is also defined by two 

other operational properties: inherent biodegradability and ready biodegradability. A compound 

is considered inherently biodegradable so long as it shows evidence of biodegradation in any test 

for biodegradability. Readily biodegradable is an operational definition that some fraction of a 

compound is ultimately biodegradable within a specific timeframe, as specified by a test method. 

Common test methods, such as those developed by the Organization for Economic 

Cooperation and Development (OECD), the Coordinating European Council (CEC), and the 

American Society for Testing and Materials (ASTM), for determining lubricant biodegradability 

are OECD 301B (the Modified Strum test), ASTM D-5864, and CEC L-33-A-934. Both OECD 

301B and ASTM D-5864 measure ready biodegradability, defined as the conversion of 60% of 

the material to CO2 within a ten day window following the onset of biodegradation, which must 

occur within 28 days of test initiation (Willing, 2001). In contrast, the CEC method tests the 

overall biodegradability of hydrocarbon compounds and requires 80% or greater biodegradability 

as measured by the infrared absorbance of extractable lipophilic compounds (CEC, 1997 and 

WISE Solutions, 2006). Unlike the OECD and ASTM methods, the CEC method does not 

distinguish between primary and ultimate biodegradability, and is considered to be a less 

stringent test (Blanken, 2006). 

Table 2 lists some of the internationally standardized test methods that measure 

biodegradability. 
Environmentally Acceptable Lubricants Section 4 - Defining “Environmentally Acceptable”

11 

Table 2. Internationally Standardized Test Methods for Measuring Biodegradability 

Test Type Test Name Measured 

Parametera 

Pass 

Levelb Method 

Ready Biodegradability 

(A substance is considered 

to be inherently 

biodegradable using any 

of these tests if it shows 

>20% biodegradability 

within the test duration) 

DDAT DOC >70% OECD 301A 

Strum test CO2 >60% OECD 301B 

MITI test DOC >70% OECD 301C 

Closed bottle test BOD/COD >60% OECD 301D 

MOST DOC >70% OECD 301E 

Sapromat BOD/COD >60% OECD 301F 

Strum test CO2 >60% ASTM D-5864 

Shake flask test CO2 >60% EPA 560/6-82-003 

BODIS test BOD/COD >60% ISO 10708 

Hydrocarbon degradability CEC test Infrared 

Spectrum 

>80% CEC L-33-A-934 

Screening tests (semi-official) CO2 headspace test CO2 >60% ISO 14593 

Source: modified from Willing, 2001 

a. DOC – dissolved organic carbon; CO2 – carbon dioxide; BOD – biochemical oxygen demand; COD – chemical oxygen 

demand 

b. Ready biodegradability is defined as complete mineralization of a compound into water, carbon dioxide, and mineral salts 

according to a specific test criterion. Pass levels indicate the percentage of complete mineralization (or ultimate biodegradation) 

as indicated by the “Measured Parameter” that must occur for a product to be classified as readily biodegradable. 

Table 3 summarizes biodegradation rates for different lubricant base oils. Ester-based oils 

have a much greater inherent biodegradation rate due to the presence of carboxylic acid groups 

that bacteria can readily utilize (Mudge, 2010). These compounds are also more water soluble 

than compounds that do not contain polar functional groups, the absence of which can reduce 

their bioaccumulation potential. 

Table 3. Summary of Differential Biodegradation Rates by Lubricant Base Oils 

Lubricant base oil Base oil source Biodegradation 

Mineral oil Petroleum Persistent / Inherently 

Polyalkylene glycols (PAG) Petroleum - synthesized hydrocarbon Readily 

Synthetic Ester Synthesized from biological sources Readily 

Vegetable Oils Naturally occurring vegetable oils Readily 

Source: Mudge, 2010 

4.2 AQUATIC TOXICITY

In addition to possessing a certain percentage of readily biodegradable material, an EAL 

must also demonstrate low toxicity to aquatic organisms. Test methods to demonstrate toxicity 

include the OECD tests series 201-4, and 209-212; and corresponding USEPA environmental 

effect test guidelines from EPA 560/6-82-002. The most common aquatic toxicity tests for 

assessing EALs are the 72-hour growth test for algae (OECD 201), the 48-hour acute toxicity test 

for daphnia (OECD 202), and the 96-hour toxicity test for fish (OECD 203). Analogous USEPA 

tests are sections EG-8, EG-1, and EG-9 of EPA 560/6-82-002 for algae, daphnia, and fish, 

respectively. A listing of all of the OECD aquatic toxicity tests is included in Table 4. 
Environmentally Acceptable Lubricants Section 4 - Defining “Environmentally Acceptable”

12 

Table 4. OECD Aquatic Toxicity Tests 

Test Title, with Species Test Number 

Growth Inhibition Test, Alga OECD 201 

Acute Immobilization Test, Daphnia sp. OECD 202 

Acute Toxicity Test, Fish OECD 203 

Prolonged Toxicity Test: 14-Day Study, Fish OECD 204 

Respiration Inhibition Test, Bacteria OECD 209 

Early-Life Stage Toxicity Test, Fish OECD 210 

Reproduction Test, Daphnia magna OECD 211 

Short-term Toxicity Test on Embryo and Sac-fry Stages, Fish OECD 212 

In general, the vegetable oil and synthetic ester base oils have a low toxicity towards 

marine organisms with the LC50 for fish toxicity reported as being ~10,000 ppm for fatty acid 

esters and glycerol esters (see Table 5) (van Broekhuizen, 2003). Water soluble PAGs may 

demonstrate increased toxicity to aquatic organisms by directly entering the water column and 

sediments rather than remaining on the water column surface as a sheen (Habereder et al. 2008). 

Table 5. Summary of Comparative Toxicity of Base Oils 

Lubricant base oil Base oil source Toxicity 

Mineral oil Petroleum High 

Polyalkylene glycols (PAG) Petroleum - synthesized hydrocarbon Lowa

Synthetic Ester Synthesized from biological sources Low 

Vegetable Oils Naturally occurring vegetable oils Low 

Source: Mudge, 2010 

a. Solubility may increase the toxicity of some PAGs 

As with many oily chemicals, the toxicity in some tests is not measureable as the LC50

exceeds the water solubility of the compound (Mudge, 2010). In such cases, it is possible to 

induce physical effects such as smothering but this is not a chemical toxic effect. Some 

methodologies use the water-accommodated fraction, the part of the oil that disperse or dissolves 

in water, although this is not a true reflection of the entire oil behavior in the marine 

environment. 

The petroleum-based oils have a greater toxicity to biota in the marine food chain 

compared to the other base oil sources (Mudge, 2010). This is related to the more rapid 

breakdown of petroleum-based oils once in the sea, which ultimately affects the potential for 

bioaccumulation. The toxicity of petroleum-based oils is also dependent upon additives used in 

formulations and metabolites produced in biodegradation. 

The use of additives is dependent on the choice of base oil and the intended function of 

the lubricant (Mudge, 2010). However, several of the more toxic compounds in formulations are 

also the ones with poor degradability. The overall product toxicity may be significantly reduced 

by switching to a biologically-sourced base oil used in conjunction with low toxicity additives. 
Environmentally Acceptable Lubricants Section 4 - Defining “Environmentally Acceptable”

13 

4.3 BIOACCUMULATION

The propensity of a substance to bioaccumulate is another property of a lubricant that is 

often considered in the qualification of a product as an EAL (Mudge, 2010). Bioaccumulation is 

the build-up of chemicals within the tissues of an organism over time. The longer the organism is 

exposed to a chemical and the longer the organism lives, the greater the accumulation of the 

chemical in the tissues (Mudge, 2010). If the chemical has a slow degradation rate or low 

depuration rate within an organism, concentrations of that chemical may build-up in the 

organism’s tissues and may eventually lead to adverse biological effects. It is, therefore, 

desirable to use compounds in formulations that do not bioaccumulate. It may not be possible to 

phase out all bioaccumulating compounds, but it is feasible to use chemicals that have a lower 

bioaccumulation potential, either through not being taken up as readily or by degrading more 

quickly both in the environment and in the organism. 

The bioaccumulation potential of a compound is directly related to its water solubility; 

chemicals that are not water soluble tend to move into fatty tissues rather than to staying in 

water. These lipophilic chemicals include most of the compounds used in the manufacture of the 

base oil in lubricants. The water solubility of a compound is related to the type of atoms in the 

molecule; compounds comprised solely of carbon and hydrogen tend to have the lowest 

solubility in water. Compounds of this type includes alkanes, which form almost 90% of the 

current base oil in conventional lubricant formulations. The inclusion of one or more oxygen 

atoms in a molecule will, in general, increase the water solubility and reduce bioaccumulation. 

Compounds with oxygen also tend to degrade more quickly in the environment or be excreted 

faster from organisms. 

Many naturally-derived base oils used in lubricants are formulated around carboxylic 

acids, which increase water solubility and degradation; therefore, their bioaccumulation potential 

is reduced in comparison to alkane-based oils. 

It has been assumed for some time that larger molecules are not bioaccumulated as they 

are unable to physically pass through the membranes of cells and be incorporated into the living 

cells (Arnot et al., 2010). Therefore, when designing lubricant formulations, the molecular size 

of the components of the base oil are considered as they will directly affect the rate of uptake. 

There has been several criteria proposed over the past few years to describe the point at which 

chemicals are no longer taken up in the body and bioaccumulated (Arnot et al., 2010). In an 

evaluation of data for esters, there was a strong link between the log Kow (the logarithm of the 

partitioning coefficient of a substance in n-octanol and water) and the log BCF (a measure of the 

bioconcentration from water into aquatic organisms), while the other factors had less welldefined relationships. The selection criteria chosen by the Canadian Government and United 

Nations Environment Program (UNEP) (Canada, 2000 and UNEP, 2001) and the U.S. 

Environmental Protection Agency (USEPA, 1999) led to cut-off log Kow values of ~5. There is 

no single criterion to adequately describe the BCF; one study proposes a holistic approach 

integrating several factors, including measured uptake and elimination rates (Arnot et al., 2010). 

Certain labeling programs, most notably the European Eco-label (see Section 5), require 

demonstration that a product is not bioaccumulative. This can be accomplished in a number of 

ways for organic compounds, such as measuring log Kow, or BCF. The two most common test 
Environmentally Acceptable Lubricants Section 4 - Defining “Environmentally Acceptable”

14 

methods for establishing bioaccumulation potential are OECD 117 and 107. For these tests, the 

test substance is added to a mixture of octanol and water and its dissolution in each phase is 

detected using gas chromatography or an infra red detector. The bioaccumulation of the 

substance is measured by establishing its partition coefficient (expressed as log Kow) in octanol 

and water. Substances that have a tendency to bioaccumulate will preferentially dissolve in the 

octanol rather than the water, and octanol mimics the fatty tissue in an organism. Therefore, the 

greater the log Kow, the greater the likelihood that the substance will bioaccumulate. 

Partition coefficients for the marine environment are normally measured on a log scale 

between 0-6. Substances with log Kow <3 are deemed not to bioaccumulate and those with log 

Kow >3 are deemed to be bioaccumulating. 

Seawater may increase the likelihood of uptake by organisms in comparison to freshwater 

due to “salting out” of lipophilic substances. Therefore, although freshwater is used in these test 

methods, as long as conservative acceptance limits are set, they can be used as an indicator of 

bioaccumulation potential in the marine environment. The use of these test methods as an 

indicator of a substance’s bioaccumulation potential can negate the need to carry out in vivo or in 

vitro fish or mussel testing. 

In summary, the level to which a component of the product is bioaccumulated in an 

organism is dependent on the environmental and biological half-lives of the compounds (some 

will degrade before being incorporated into an organism and some will be metabolized within the 

organism), as well as the lipophilic nature of the compounds (as measured by water solubility). 

Any component that has low water solubility may potentially bioaccumulate in an organism. In 

the case of lubricants, fatty acid-containing components have reduced bioaccumulation potential 

due to greater water solubility and higher biodegradation rates. This is one distinct advantage in 

using esters over the other carbon and hydrogen alone base oil types (see Table 6). 

Table 6. Summary of Bioaccumulation Potential by Base Oil Types 

Lubricant base oil Base oil source Potential for 

Bioaccumulation 

Mineral oil Petroleum Yes 

Polyalkylene glycols (PAG) Petroleum - synthesized hydrocarbon No 

Synthetic Ester Synthesized from biological sources No 

Vegetable Oils Naturally occurring vegetable oils No 

Source: Mudge, 2010 

4.4 SUMMARY OF ENVIRONMENTALLY ACCEPTABLE LUBRICANT CHARACTERISTICS

A summary of the major factors regarding biodegradation, toxicity and bioaccumulation 

potential, for each of the base oil types is shown in Table 7. In this table, the three major criteria 

are presented for each base oil and color-coded to indicate the environmental outcome. The 

biodegradability of a lubricant reflects that of the lubricant’s base oil, while the degree of aquatic 

toxicity is typically a consequence of the performance enhancing additives (or thickening agents) 

within the formulation. The base oils that degrade quickly are considered more preferable than 

those that do not rapidly degrade, although there might be a trade-off with regard to the depletion 

of oxygen during compound metabolism. The compounds that do not bioaccumulate and are 
Environmentally Acceptable Lubricants Section 4 - Defining “Environmentally Acceptable”

15 

relatively less toxic are considered more preferable than those that bioaccumulate and have 

higher toxicities. 

Table 7. Comparative Environmental Behavior of Lubricants by Base Oil Type 

Lubricant base 

oil Base oil source Biodegradation Potential for Bioaccumulation Toxicity

Mineral oil Petroleum Persistent / 

Inherently Yes High 

Polyalkylene 

glycols (PAG) 

Petroleum - synthesized 

hydrocarbon Readily No Lowa

Synthetic Ester Synthesized from 

biological sources Readily No Low 

Vegetable Oils Naturally occurring 

vegetable oils Readily No Low 

Source: Mudge, 2010 

a. Solubility may increase the toxicity of some PAGs

Currently, a majority of lubricant base oils (mineral oils) have the lowest biodegradation 

rate, a high potential for bioaccumulation, and a measurable toxicity towards marine organisms. 

In contrast, the base oils derived from oleochemicals (vegetable oils and synthetic esters) 

degrade faster, have a smaller residual, do not bioaccumulate appreciably and have a lower 

toxicity to marine organisms. PAG-based lubricants are also generally biodegradable and do not 

bioaccumulate; however, some PAGs may be more toxic due to their solubility in water. On the 

basis of this simple comparison, lower environmental impacts will arise if a greater proportion of 

base oils are manufactured from biologically-sourced materials. 
Environmentally Acceptable Lubricants Section 5 - Environmentally Acceptable Lubricant Labeling Program

16 

SECTION 5 

ENVIRONMENTALLY ACCEPTABLE LUBRICANT LABELING 

PROGRAM 

To minimize confusion in the marketplace and to increase public awareness and create 

sensitivity for environmentally preferable products, national and international labeling programs 

have been developed, primarily in Europe (Habereder et al., 2008). These labeling programs 

have defined and established methods to measure the properties of a lubricant that would qualify 

it as being environmentally acceptable. The labeling programs can aid the purchasing decisions 

of a vessel operator by helping to remove uncertainty. The principal national and international 

labeling certification programs for biolubricants and EALs are presented below. 

5.1 NATIONAL LABELING PROGRAMS 

5.1.1 Blue Angel 

The first national labeling scheme for lubricants was the German Blue Angel label, 

developed in 1988. Criteria have been developed for several classes of lubricants, including 

hydraulic fluids, lubricating oils, and greases. In order to qualify for certification, a lubricant 

must possess the following characteristics: biodegradability; low toxicity to aquatic organisms; 

non-bioaccumulative; and no dangerous components (such as carcinogens or toxic substances as 

defined by Germany’s Ordinance on Hazardous Substances). A product must also pass technical 

performance characteristics appropriate for its use. Biodegradability can be demonstrated using 

OECD tests 301B-301F to measure ultimate biodegradability or CEC L-33-A-934 to measure 

primary biodegradability. Blue Angel’s requirement for ultimate biodegradability is the primary 

difference between the Blue Angel labeling certification program and other national and 

international certification programs. Aquatic toxicity is determined according to OECD 201-203. 

Products receiving the Blue Angel certification must also pass a series of technical 

performance requirements that depend on the class of lubricant. Unlike some of the other 

labeling programs, the Blue Angel certification does not have any requirements for renewability; 

consequently, lubricants comprised completely of petroleum-sourced components can receive 

Blue Angel certification. Nevertheless, Blue Angel certification is considered rather stringent, 

and the proportion of lubricants receiving this certification remains low, with the majority being 

hydraulic fluids (Habereder et al., 2008). A complete list of all lubricants that carry the Blue 

Angel certification can be found at http://www.blauer-engel.de/en/products_brands/ 

search_products/search_for_products.php. 

5.1.2 Swedish Standard 

Another national labeling scheme for lubricants is the Swedish Standard, which includes 

standards for hydraulic fluids (SS 155434) and greases (SS 155470). Evaluation of a lubricant 

under the Swedish Standard involves testing for biodegradability and aquatic toxicity, as well as 

sensitizing properties of a lubricant formulation and its components (Habereder et al., 2008). The 

Swedish Standard evaluates biodegradability using ISO test methods (e.g., ISO 9439), and has 

varying requirements, depending upon class, for renewable resources content (SP 2010). The 
Environmentally Acceptable Lubricants Section 5 - Environmentally Acceptable Lubricant Labeling Program

17 

Swedish Standard is unique because it was conceived and developed as a collaborative project 

between government and industry. This program has more listed lubricant products, particularly 

hydraulic fluids, than any other national labeling program (IENICA, 2004). 

5.2 INTERNATIONAL LABELING PROGRAMS

5.2.1 Nordic Swan 

The first international labeling program for EALs was the Nordic Swan program, 

encompassing Norway, Sweden, Finland, Iceland, and Denmark. This program was initially 

introduced for hydraulic oil, two-stroke oil, grease, and transmission and gear oil (IENICA, 

2004). The Nordic Swan certification addresses biodegradability, aquatic toxicity (OECD 201 

and 202), technical performance, and renewability. The renewability requirements are the highest 

of all the labeling programs (e.g., at least 65% renewable content for hydraulic fluid, 

transmission fluid, gear oil, or grease, and at least 50% for two-stroke oil). Consequently, very 

few lubricants bear the Nordic Swan label (Habereder et al., 2008). 

5.2.2 European Eco-label 

The European Union has adopted a single European Eco-label. The Eco-label is 

considered to be the first major advancement towards creating a single international standard, 

and is becoming the most generally accepted label. The Eco-label for lubricants was established 

in 2005, and includes hydraulic fluids, greases, and total loss lubricants, such as two-stroke oils. 

This labeling scheme consists of seven criteria encompassing biodegradability, aquatic toxicity, 

bioaccumulation, and the presence of certain classes of toxic substances (Habereder et al., 2008). 

A complete list of all lubricants that carry the European Eco-Label can be found at 

http://www.eco-label.com/default.htm. 

The ecological criteria for Eco-label lubricants aim at promoting products that have a 

reduced impact on the water and soil during their use and contain a large fraction of biologicallybased material. Since this is the most widely accepted labeling program, the requirements for this 

labeling scheme are described in detail below. 

5.2.2.1 Dangerous Materials 

Before a lubricant can be considered for the Eco-label, it is determined that neither the 

formulation nor any of the main components are on the list of R-phrases (risk phrases) pertaining 

to environmental and human health hazards according to the European Union Dangerous 

Preparations Directive (IENICA, 2004). These include qualities such as explosiveness, 

flammability, carcinogenic potential, volatility, potential to cause birth defects, etc. 

5.2.2.2 Toxicity 

Aquatic toxicity can be evaluated either for the complete formulation and main 

compounds (those compounds comprising at least 5% of the formulation) or for each constituent 

substance. Greases must be evaluated for each constituent substance unless it can be shown that 

the thickening agent is at least inherently biodegradable (see below). All formulations and 

components must pass both OECD 201 and 202 for acute toxicity testing, and OECD 210 or 211 

for chronic toxicity testing. If evaluated for the formulation and main constituents, the LC50 (i.e., 
Environmentally Acceptable Lubricants Section 5 - Environmentally Acceptable Lubricant Labeling Program

18 

concentration of a compound or mixture that will kill half of the sample population of a specific 

test-organism in a specified period) of hydraulic fluids must be at least 100 mg/L and the LC50 of 

greases, two-stroke oils, and all other total loss lubricants must be at least 1000 mg/L (European 

Commission, 2009). If the evaluation is based on each constituent substance, then constituents 

that comprise less than 20% of hydraulic fluids can have an LC50 of 10-100 mg/L or have a no 

observed effect concentration (NOEC) of 1-10 mg/L; constituents that comprise less than 5% of 

hydraulic fluids can have an LC50 of 1-10 mg/L or have a NOEC of 0.1-1 mg/L; and constituents 

that comprise less than 1% of hydraulic fluids can have an LC50 of less than 1 mg/L or have a 

NOEC of 0-0.1 mg/L. For greases, two-stroke oils, and other total loss lubricants, the respective 

percentages are 25%, 1%, and 0.1% (European Commission, 2009). 

5.2.2.3 Biodegradability and Bioaccumulation 

Ninety percent or more of the total hydraulic oil formulation (75% for greases or twostroke oils) must be ultimately biodegradable, as determined according to any of OECD tests 301 

A-F, or equivalent. Less than 5% of the hydraulic oil formulation (20% for greases or two-stroke 

oils) must be inherently biodegradable. Inherent biodegradability can be defined as at least 20%, 

but less than 60% or 70% biodegradable (depending on the test), for any of OECD 301 A-F, or it 

can be defined as greater than 70% biodegradation in the OECD 302C test (or equivalent), or 

greater than 60% biodegradation in the ISO 14593 test (European Commission, 2009). 

In addition to being biodegradable, a lubricant must not have the potential to be 

bioaccumulative. A lubricant is considered not potentially bioaccumulative if one of the 

following conditions is met: it has a molar mass greater than 800 g/mol or a molecular diameter 

greater than 1.5 nm; it has a log Kow less than 3 or greater than 7; or it has a measured BCF less 

than 100 L/Kg (European Commission, 2004). Log Kow , which can be assessed using OECD 

107, 117, or 123, or calculated, can be used to demonstrate bioaccumulation potential for organic 

compounds only. For all other compounds, BCF must be measured using the flow-through fish 

test given by OECD 305 (European Commission, 2004). 

5.2.2.4 Restricted Substances 

Lubricant formulations must not include certain specific substances, including 

halogenated organic compounds, nitrite compounds, metals or metallic compounds (with the 

possible exception of sodium-, potassium-, magnesium-, lithium-, aluminum-,and calcium-based 

soaps) (European Commission, 2004). 

5.2.2.5 Renewable Content 

At least 50% of hydraulic oils and two-stroke oils, and at least 45% of greases, must 

consist of renewable materials, with renewable defined as vegetable oils or animal fats 

(European Commission, 2004). Given that 70-90% of a lubricant or lubricant grease is the 

formulation’s base oil, this requirement effectively excludes mineral oil lubricants from Ecolabel certification. 

5.2.2.6 Other 

The final criteria for the Eco-label are for technical performance, which are specific to 

the lubricant class in question. 
Environmentally Acceptable Lubricants Section 5 - Environmentally Acceptable Lubricant Labeling Program

19 

5.2.3 OSPAR

The offshore oil and gas industry is highly regulated, particularly in the North Sea, 

compared to other marine industries (Pearce et al, 2010). Considerable attention is given to the 

chemicals used on and discharged from offshore oil facilities. Some of these chemicals, such as 

well chemicals, are deliberately discharged during normal use, similar to the discharge of total 

loss lubricants by the marine industry. 

The Convention for the Protection of the Marine Environment of the North-East Atlantic 

(OSPAR Convention)2 is the current legal instrument guiding international cooperation on the 

protection of the marine environment of the North-East Atlantic. Work under the Convention is 

managed by the OSPAR Commission, which is made up by representatives of 15 contracting 

Governments and the European Commission (represents the European Union). 

The standards for environmental compliance, which are defined within the OSPAR 

Harmonized Mandatory Control Scheme (HMCS) regulations, require component level testing of 

chemicals released to the marine environment for biodegradation, bioaccumulation, and toxicity. 

These standards, which apply to the North Sea, are being adopted by most other oil and gas 

regulators around the world (including Australia, Canada, India, Indonesia and New Zealand) as 

they are considered to be the most appropriate for measuring the overall impact of a substance – 

not just its persistence (Pearce et al., 2010). Although these regulations do not cover the shipping 

industry, they may be considered the most appropriate standards for measuring the impact of 

released chemicals in the marine environment. 

The OSPAR standards measure environmental performance of chemicals in terms of 

persistence (biodegradation in seawater over a 28-day period, by OECD 306), bioaccumulation 

(evaluation by measuring Kow using OECD 117 or 107) and marine toxicity to four North Sea 

species (algae, copepods, sediment reworkers and bottom-dwelling fish). Testing is carried out 

on each component, and must be conducted by an approved third-party laboratory. The OSPAR 

protocols for methods for the testing of chemicals used in the offshore oil industry are available 

online (OSPAR, 2006). The mechanisms set out in the HMCS to ensure and actively promote the 

continued shift towards the use of less hazardous substances (or preferably non-hazardous 

substances) are described in the OSPAR Decision 2000/2 on a Harmonised Mandatory Control 

System for the Use and Reduction of the Discharge of Offshore Chemicals (OSPAR, 2000). 

5.3 SUMMARY OF ENVIRONMENTALLY ACCEPTABLE LUBRICANT LABELING PROGRAMS

A summary of the major EAL labeling programs discussed in this section (including 

biodegradation, toxicity, bioaccumulation potential and other criteria) is provided in Table 8. 

 

2

 www.ospar.org 
Environmentally Acceptable Lubricants Section 5 - Environmentally Acceptable Lubricant Labeling Program

20 

Table 8. Comparison of EAL Labeling Programs 

EAL 

Labeling 

Program 

Biodegradability Aquatic 

Toxicity Bioaccumulation Other Criteria 

Blue Angel 

(Germany) 

OECD 301B-F (ultimate 

biodeg.) or CEC L-33-A934 (primary biodeg.) 

OECD 201-203 OECD 305 

A-E or Kow

Dangerous materials; 

Technical 

performance 

Swedish 

Standard 

ISO 9439 NA None Renewable content; 

Sensitizing properties 

Nordic Swan NA OECD 201-202 None Renewable content; 

Technical 

performance 

European 

Eco-label 

OECD 301 A-F (ultimate 

biodeg.), OECD 302C or 

ISO 14593 

OECD 201 and 

202 (acute) & 

OECD 210 or 

211 (chronic) 

OECD 107, 117 or 123 

(Kow for organic 

compounds) or OECD 

305 

Dangerous materials; 

Restricted substances; 

Renewable content; 

Technical 

performance 

OSPAR OECD 306 (degradation 

under marine conditions) 

Marine toxicity 

to 4 species 

OECD 117or 107 (Kow) 

NA - Not available 
Environmentally Acceptable Lubricants Section 6 - Conclusion

21 

SECTION 6 

CONCLUSION 

Because much of the lubricant lost from a vessel directly enters the aquatic environment, 

there is a greater focus on encouraging the implementation of EALs on vessels (see 2008 VGP, 

page 24) (Carter, 2009). For all applications where lubricants are likely to enter the water, EAL 

formulations using vegetable oils, biodegradable synthetic esters or biodegradable polyalkylene 

glycols as oil bases instead of mineral oils can offer significantly reduced environmental impacts 

across all applications. Although their use is increasing, EALs continue to comprise only a small 

percentage of the total lubricant market. 

Among types of EALs used in vessels, hydraulic fluids are the most prevalent. Along 

with chain saw oil, more hydraulic fluids carry the Blue Angel and European Eco-label than any 

other class of lubricant. A major reason for the success of environmentally acceptable hydraulic 

fluid is that some of the performance issues associated with EALs in open systems (particularly 

those formulated with vegetable oil derived base oils), such as oxidation, temperature sensitivity, 

and biodegradation following exposure to water, are less problematic in this closed system 

(ACE, 1999). 

Stern tube leakage is a significant source of lubricant oil inputs to the aquatic 

environment; therefore, the benefit of replacing mineral-oil-based stern tube lubricants with 

EALs is expected to be considerable. Because of the inevitability of leaks, stern tube lubricants 

are also subject to water influx and increased biodegradability associated with water contact. 

While still a niche market, environmentally acceptable stern tube lubricants formulated from 

PAGs have shown to perform as well as a conventional stern tube lubricant, with the additional 

benefit of maintained viscosity following water influx (Sada et al., 2009). 
Environmentally Acceptable Lubricants List of Figures

SECTION 7 

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