Industry-wide regulations mean that gas oil can have FAME levels of up to 7%. There have been reports that FAME can cause problems for machinery and fuel tanks, but these can be avoided with proper storage and regular checks. By taking care of your tanks and filters, you can keep everything running smoothly when using gas oil

What is FAME?

Fatty Acid Methyl Esters, or FAME, are fatty acids that can be used as biodiesel. They come from renewable sources, including recycled cooking oils, animal fats and plant oils, which means they can help reduce CO2 emissions. However, FAME also absorbs and retains water which promotes bacteria and algae growth, that can lead to machinery problems, like contamination, clogged filters and lower performance, if coupled with poor fuel storage and maintenance.

Changing regulations around biodiesels

The Renewable Transport Fuel Obligation (RTFO) is one of the government’s main policies for reducing greenhouse gas emissions from fuel used in vehicles and machinery. It states that 8.5%of fuel used in these applications must come from sustainable and renewable sources, and this percentage will increase to 12.4% by 2032.

To meet these regulations, the make-up of gas oil incorporates a bio element, and British Standard fuel can now have up to 7% FAME content.

Potential risks of FAME

Due to FAME’s ability to attract and hold water, as well as its detergency properties, it can lead to problems if gas oil isn’t stored properly.

  • Degraded components – many common rubbers, plastics and surface coatings can degrade after contact with FAME
  • Contamination – due to its ability to hold water, bacteria, algae and mould can grow
  • Clogged filters – it can cause residual redeposits, leading to clogged filters
  • Shorter shelf life – discolouration, gum formation and separation of crude-derived biodiesel elements sometimes occur
  • Reduced performance – waxing issues can increase, leading to a lower performance in cold weather


Steps you need to take to keep your machinery in good condition

When using gas oil, there are ways to protect your machinery against FAME’s potential issues. Based on advice from the UK and Ireland Fuel Distributors Association (UKIFDA) and our own experience, we recommend that you:

  • Check your tank regularly – look for any signs of damage to your tank, including to the filters, pipework and seals. Our drivers will do this for you before each delivery, but you should also do it after delivery. If you need a new tank, please speak to your local depot or fuel account manager to discuss the range of static and transportable tanks available.
  • Clean your tank and remove any water – Over time condensation can cause water to build up inside the tank. Check your tank often and have a regular maintenance programme to remove any water.
  • Use your fuel – try to limit the storage time and keep tanks topped up to reduce air flow, which can attract moisture.
  • Look out for contamination –if you notice any water, dirt or mould in the tank or fuel, contact a specialist for assistance. The team at Watson Fuels can point you in the right direction.
  • Replace filters regularly – to avoid them getting clogged, replace filters every two to three deliveries.
  • Choose a reputable distributor – the UKIFDA advises that you should only buy fuel from a reputable distributor. At Watson Fuels, we are proud members of the UKIFDA, and you can trust that our fuels always meet British Standards and come from the highest quality UK-based suppliers.


Speak to our experts

If you have any concerns about your storage tank or looking after your machinery, please contact your local depot or fuel account manager.

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