SECTOR FOCUS: BIOLUBRICANTS


Biolubricants – biodegradable, biobased or both?


Dr. Jens Kubitschke, OXEA GmbH, Germany


When it comes to biolubricants, terminology can be confusing. This article should explain some of the relevant terms and provide an overview of the corresponding requirements according to current regulations.


Becoming more sustainable is one of the key tasks of today’s society – and for the lubricants industry as well. Accordingly, the use of biolubricants is increasing, especially in applications with potential loss to the environment, e.g. hydraulic fluids or railway greases. Even though definitions of the term biolubricant exist,1


The same is true for the EU Ecolabel.3 The new criteria common usage of this term shows


no consensus whether the respective substances have to be biodegradable, biobased or both. In general, biodegradable substances don’t necessarily have to be biobased and biobased substances don’t necessarily have to be biodegradable. It solely depends on the molecular structure whether a substance is biodegradable, not on its origin. Therefore, it is important to distinguish between biodegradable and biobased substances, especially as regulations refer to these terms. The term biolubricants in its common usage is not precise enough.


In contrast, the term Environmentally Acceptable Lubricant (EAL) is clearly defined in the Vessel General Permit (VGP) 20132


According to the Vessel Incidental Discharge Act (VIDA), signed into law December 2018, all provisions of the VGP remain in force. Correspondingly, EALs have to be biodegradable, minimally-toxic and not bioaccumulative. Lubricants with labels like the EU Ecolabel, Blue Angel, Nordic Swan and some others are accepted as compliant. A biobased content is not required by the VGP.


22 LUBE MAGAZINE NO.150 APRIL 2019


established in November 2018 no longer require biobased content. However, the main components of the lubricant need to be readily biodegradable and non-bioaccumulative. Furthermore, certain hazardous substances are restricted and specific requirements concerning aquatic toxicity apply. Precise values of the requirements can be found in the Annex of the Commission Decision (EU) 2018/1702.3


An excellent overview of the corresponding analytical methods can be found in an article by V. Bouillon in a previous edition of Lube magazine.4


Base oils and


additives that are in compliance with the EU Ecolabel criteria can be found in the Lubricant Substance Classification (LuSC) list.5


Concerning biodegradability, the degree of biodegradation (in a certain amount of time under certain conditions) is of high importance.


and encounters broad acceptance.


The main components of the lubricant have to be readily biodegradable, inherently biodegradable components are limited (<25% for partial loss lubricants (PLL) down to <5% for total loss lubricants (TLL)). To be accepted as readily biodegradable, respective substances need to show >60 % biodegradation within 28 days in tests based on oxygen depletion or carbon dioxide generation and >70% in tests based on dissolved organic carbon.


Continued on page 24


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