Measuring the environmental
friendliness of lubricants
|Ecolabels are mainly geared towards loss lubricants or products that may cause damage to the environment as a result of accidents. Biolubricants have a lower impact on the environment because they pose little threat to surface and marine life (and contain fewer health risks); preferably, they consist primarily of renewable raw materials.
Pollution can be limited by using biolubricants. Biolubricants are also safer with regard to occupational health; they cause less skin irritation, have a higher flash point while also retaining the correct viscosity, contain lower levels of volatile organic compounds (VOCs) and have a lower emission of VOCs. The use of biolubricants can have a positive influence on costs such as environmental fines, safety fines, by reducing liability and cleaning costs in the event of spills and accidents.
Using biolubricants based on renewable raw materials decreases the dependence on fossil fuels. The current climate crisis has increased awareness of the influence of the application of lubricants on the use of energy by hydraulic engineering objects and installations. And with good reason, too: it is claimed that applying certain lubricants (regardless of whether they carry an ecolabel) may reduce energy costs by as much as 10% to 25%. However, no ecolabel has introduced any such requirement yet.
However, there are criteria that dictate the renewable raw material content. In the European Ecolabel for lubricants, this requirement is set to 50% for hydraulic fluids, 45% for greases and 70% for loss lubricants. The Blue Angel Ecolabel states that the base oil of greases, which constitutes approximately 80% of the final product, needs to consist of either vegetable or synthetic esters. This limits the amount of fossil raw materials and CO2 that are released into the ecosystem. Concerns about the sustainable production of feedstock for base oils has resulted in the development of certification systems for certain feedstocks. Palm oil can be bought certified by the RSPO Soya oil can be bought certified by the RTRS.
The use of biolubricants can, in addition, save more energy because of a higher viscosity index and improved heat transfer. The advantage of a higher viscosity index is that there is a wider range of products available with lower viscosity classes for certain applications of biolubricants. This is not the case with mineral lubricants. The lower viscosity of biolubricants, combined with its improved heat transfer, will sharply reduce energy consumption.
The influence of the applied lubricant on the energy consumption of installations (and on the greenhouse effect and CO2 emissions) is determined primarily by friction. Eventually, wear of parts and the lubricant's life span can also have an effect. If these effects can be sufficiently and reliably quantified, this could for instance be included in the next revision of the European Ecolabel's criteria by means of Life Cycle Analysis (LCA) studies.
In various European countries and regions, ecolabel institutions have drawn up criteria that lubricants have to meet in order to be allowed to carry an ecolabel. Lubricants can be considered for ecolabels (such as Blue Angel, Swedish Standard or Nordic Swan ) if they meet criteria regarding: biodegradability (biodegradation, persistence and bioaccumulation potential), (aquatic) toxicity, renewable raw material content and other environmental and health risks.
A comparison between ecolabels shows that no two labels are the same. In order to harmonise the various definitions, the European Ecolabel for lubricants was created in 2005. Within the current market supply, two classes of biolubricants may be distinguished. For more information refer to: Placing sustainability requirements on purchasing biolubricants (PDF).
Loss lubricants are products with a lubricating and sealing function and are meant to prevent wear from friction or to prevent contamination by particles, such as sand during excavation works. (and are, therefore, constantly applied under pressure). This method of application makes emission into the environment inevitable. This particularly applies to the use of greases and oils to lubricate (semi-) open systems such as stern tubes and gearboxes, but also to concrete release agents.
Renewable Raw Materials
Materials from non-fossil sources such as plants or animals. Among other materials, vegetable and animal fats and oil are used to manufacture biolubricants.
The flash point of a substance is the lowest temperature at which the substance generates enough vapour to be able to ignite when it comes into contact with an ignition source.
Viscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. The less viscous a lubricant the easier it flows (fluidity).
The viscosity index indicates how an oil reacts to high and low temperatures. The higher the viscosity index, the less the properties of the oil change under the influence of temperatures. An oil with a high viscosity index thickens less at low temperatures and does not dilute as much at high temperatures compared to oils with a low viscosity index. A high viscosity and a high viscosity index are two entirely different things. The viscosity index relates to the width of the range, not to the highest value. 5W50 oil, for instance, has a higher viscosity index than 20W50. 5W50 retains its properties through a wider range of temperatures than 20W50. Furthermore, 5W50 is a thinner oil than 20W50.
Biodegradation is a property of all organic materials that will gradually disintegrate into components that can serve as nutrients to plants and animal life. Micro-organisms that stimulate this disintegration are very important for this process. In other words, biodegradation is the metabolic degradation of all organic materials by living organisms.
This property indicates the amount of time a substance remains in the environment.
The accumulation of chemicals in living organisms such as plants or animals in the food chain.
The potential of a substance to adversely affect the physiological process in an organism. Two main toxic effects are distinguished: direct or acute toxicity and long-term or chronic toxicity.