Guidance

Using drop-in fuels in combustion plant in place of gas oil: RPS 337

Published 4 July 2025

Applies to England

This regulatory position statement (RPS) does not change your legal requirement to comply with your environmental permit when you operate a combustion plant to which the Environmental Permitting regulations apply.

However, the Environment Agency will not normally take enforcement action against you if you do not comply with this legal requirement provided that:

  • your activity meets the description set out in this RPS

  • you comply with the conditions set out in this RPS

  • your activity does not cause (and is not likely to cause) pollution of the environment or harm to human health

1. Activity this RPS applies to

This RPS applies to combustion plant in England which are allowed to burn gas oil as a fuel under an Environmental Permit but wish to use alternative drop-in fuels.

2. Conditions you must comply with

You must:

  • hold an Environmental Permit that allows the combustion of gas oil

  • confirm with the original equipment manufacturer that the drop-in fuel is suitable for use in your combustion plant

  • comply with relevant emission limits and fuel specification in your permit

  • notify the Environment Agency before you use this RPS by contacting your local Regulatory Officer

  • only combust hydrotreated vegetable oil (HVO) that meets EN15940

  • keep records for 2 years from the date of the last use of the RPS to show that you have complied with this RPS and make these records available to the Environment Agency on request

You must not combust fuels other than those mentioned in your environmental permit or this RPS.

3. Things to note

The Environment Agency will amend environmental permits over time to allow the use of drop-in fuels without needing an RPS.

Replacing fossil fuels may affect your reporting requirements under the UK Emissions Trading Scheme (ETS). Check with your ETS regulator.  

3.1 Hydrotreated vegetable oil

HVO may be partially manufactured from Palm Oil. You should check that the HVO supply source meets your company’s sustainability criteria.  

4. When you must check back

The Environment Agency intends to review this RPS by 4 July 2028.

The Environment Agency can withdraw or amend this regulatory position before the review date if they consider it necessary. This includes where the activity that this RPS relates to has not changed.

You will need to check back from time to time, including at and before the review date, to see if this RPS still applies.

This RPS remains in force until it is removed from GOV.UK or is otherwise identified as having been withdrawn.

You can subscribe to email updates about this RPS. These will tell you if the RPS has changed and when it has been withdrawn.

5. If you cannot comply with this RPS

If you operate under this RPS but can no longer comply with it, you must stop the activity to which this RPS relates and must tell the Environment Agency immediately by emailing enquiries@environment-agency.gov.uk with RPS 337 in the subject. 

6. Contact the Environment Agency

If you have any questions about this RPS email enquiries@environment-agency.gov.uk with RPS 337 in the subject.