A well-attended meeting held at the East Mendip Study Centre heard John Cranshaw, technical manager of Fuchs Lubricant (UK) plc talk about biodegradable oils. His thought provoking title of 'What about global warming?' began by explaining where our 'conventional' oil comes from and when it is likely to run out. For example the reserves of oil and gas in the North Sea have been in decline since 2000 and expected to end by 2025. We now consume as much oil in six weeks as we used in the whole of 1950. Energy costs are rising steeply and oil-based products will never be cheap again. John then described what is meant by biodegradable oils, which are mainly derived from oilseed rape, the yellow fields being a common sight in the UK. In order to be classified as biodegradable they must do so within twenty-one days by the action of bacteria, leaving only water and carbon dioxide. Replacing mineral oils with such liquid vegetable oils could reduce the carbon footprint of the lubricants industry. They can be used in all types of applications across a wide range of industries. Currently over 90% are derived from crops but they can now be made synthetically so this figure will drop to around 60%.

John then explained the claimed advantages of these oils, such as high temperature capabilities and low toxicity. Because they have very good ageing stability compared to mineral oils (which will deteriorate due to oxidisation) then less oil changes would be required, leading to cost savings.

John concluded his talk with a case study of how the Eden Project in Cornwall now use biodegradable oils in over sixty items of plant and equipment, ranging from hydraulic excavators to chainsaws.

The lively question and answer session touched on the relative costs of both types of oils, the difficult issue of balancing food versus fuel when growing these crops, the possibility of recycling rather than allowing it to degrade and the reluctance of some engine manufacturers to extend oil changes.

Andy Shakeshaft gave the vote of thanks for a highly topical subject from a very accomplished and knowledgeable speaker.