The recent cold snap has thrown into focus the varying quality standards of biodiesel, and the different behaviour of the recycled materials in them in cold weather conditions.

Generally, biodiesel has a slightly higher freezing point than standard diesel. It is generally believed that biodiesel made from vegetable oil behaves very similarly to standard diesel, freezing at around -12 degrees. Blends made from 'tropical oils' such as palm oil, or fuel made from animal fat struggle in the northern European climate, with a freezing point much nearer to zero degrees. But due to the number of different production methods, there are no standards for production of biodiesel. Only expensive high-end rapeseed oil-based biodiesel has a set European standard - EN 14214