Biodiesel: What you need to know

13 April 2022

A picture of a fuel tank being topped up.

Very few reports of fuel filter blocking issues have been received by the NFU and NFU Scotland over the past year, but the NFU is aware of a small number of new incidents.

The NFU has been working with a group of industry stakeholders and government representatives to address the problem. One output from the working group has been a new upper limit on the number of contaminant particles in fuel supplied to the UK market of 10,000 parts per million or less.

What advice is available?

  • The NFU’s science and regulatory affairs team has written a briefing for members providing information on the issue and an update on actions to investigate the causes and solutions. This is available to download at the end of this page.
  • The responses previously received from the NFU's biodiesel survey have been analysed. A report of the results was presented to the Agricultural Filter Blocking Taskforce, of which both the NFU and NFU Scotland are members, alongside the Department for Transport, British Standards Institute and various fuel producers, suppliers and trade associations.

The report was greatly appreciated by the taskforce, as a way of better understanding the nature and scope of the problem. The results will be used to inform the direction of future testing and actions.

What exactly has happened?

The reports are of fuel filters in farm machinery blocking up unusually quickly, needing to be replaced far more frequently than expected. The substance found to be blocking the filters varies between reports but commonly consists of a black slime or a clear wax. Affected machinery includes a range of makes and models, costing members both time and money.

What is the NFU doing?

The NFU and NFU Scotland have been in discussions with the Department for Transport, as well as a range of industry experts and stakeholders to try to understand the cause of the issue.

Representatives of both fuel producers and distributors acknowledge that agricultural users of diesel are experiencing problems with material becoming trapped in filters causing fuel starvation, however, to date, there has been no definitive answer to the cause.

NFU NFUS logo_71081

The NFU is aware that numerous fuel samples have been tested and the results show that samples are within specification.

We would like to make members aware that, as this is a complex problem, and the exact causes and solutions to the problem are still to be fully identified.

What to do if you've experienced issues

Email us directly: [email protected]

File downloads

Biofuel Transport

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