Biodegradable lubricants

It is known that one litre of oil can pollute one million litres of water. If oil gets into drinking water or groundwater, it can cause great ecological damage. The smallest leak in a lubrication system can severely pollute a nature reserve. Therefore, it is particularly important that in sensitive areas such as forests, at water points or even in agriculture, only lubricants are used that do not pollute the ecosystem and are degradable within a manageable time horizon. Biodegradable lubricants with special properties are being developed to ensure that lubricants used as intended do not cause lasting damage in these sensitive areas.

Biodegradability of substances primarily describes the degradation caused by naturally occurring microorganisms, e.g., bacteria, yeasts or fungi. These decompose molecules to feed themselves, attacking chemical structures that are more vulnerable to microbial decay than others. This is why vegetable oils, for example, biodegrade faster than petroleum.

Biodegradable lubricants mostly consist of vegetable oils (rapeseed oil, sunflower oil) or synthetic esters. They must not contain any toxic heavy metals as additives.

Biodegradable lubricants must meet special requirements, which are defined e.g., in the EEL (European Eco Label), by the RAL-UZ (Blauer Engel eco-label) or the OECD (Organization for Economic Cooperation and Development). At least 95 % by weight of the lubricant used must be readily biodegradable and no more than 2 % by weight may be non-biodegradable components. Standardised OECD tests are used to prove biodegradation and to classify the product. For example, the entire product must be completely degraded within a reasonable period of time and no bioaccumulative substances must be formed. According to the OECD 301B test procedure, a lubricant must decompose by 60% in 28 days to be classified as "rapidly biodegradable".

Biodegradable lubricants are used in agriculture, forestry, water management, shipping or mining. Typical examples are:

• Saw chain oils in forestry
• Biodegradable hydraulic oils for construction machinery or harvesters, tractors or hydroelectric power plants
• Biodegradable lubricating greases e.g., for sewage treatment plants, sluices in waterworks, railways or hydrants