A Failed Domestic Oil Storage Tank Risk Assessment - The Facts

I've carried out a Domestic Oil Tank Spillage & Fire Risk Assessment for your oil tank and it failed on one or more issues and you are now wondering...

"What should I do?"

Obviously an official form with 'failed' written on it does not always go down well with the customer and some of the points may seem to be pedantic - you may even think that I'm angling for more business, but please "don’t shoot the messenger”, read on and all will become apparent.

Why Did I Do A Risk Assessment?

As an OFTEC (Oil Fired Technical Association) registered Professional I am required to carry out a Domestic Oil Tank Spillage & Fire Risk Assessment as a part of each annual service and for each new oil appliance installation. If from that risk assessment I am aware that your oil tank does not comply with current regulations (even if it was installed long before these regulations came into being) and I do not make you aware - as 'the professional' - I could be considered negligent or even liable if a problem occured such as the one pictured above.

So the TI133 Domestic Oil Tank Spillage & Fire Risk Assessment report has two purposes;

Firstly for your information. I'll give you what I think are the facts, so YOU are able to make an informed decision about what action, if any, you should take.

Secondly to cover my assets (to be polite) & livelihood.

Your Home Insurance

It is possible that your household/buildings insurance policy could have a clause that you may not be covered in the event of a fire or a pollution incident if your tank does not comply with current regulations. Does you policy cover you for the clean up oil leaks?

If you do nothing else I urge you check your insurance policy!

PROTECTION FROM FIRE (To comply with current regulations)

Adequate fire protection must be given to protect the oil tank from a fire originating within a building or garden or neighbouring property. Therefore unless the tank is situated at least;

  • 1.8m from a flue terminal, window or door,

  • 1.8m from a wall of a building, or the eaves of a building, that has less than a 30 minute fire resistance - a ‘building’ can be any building in which a fire could start such as a house, garage, greenhouse, garden shed, even a derelict building in your garden.

  • 760mm from a non-fire-rated boundary line (fire-rated means 30 minute fire resistance and at least 300mm higher than the top and 300mm past the ends of the tank).

  • 600mm away from screening, for example a trellis or foliage that does not form part of the boundary – to allow inspection of the oil tank.

…then a fire barrier with a minimum of a 30 minute fire resistance must be installed to give protection to the tank and must be at least 300mm bigger in every direction of the side and top of the tank.

Regardless of any of the above, the installation should incorporate a non-combustible base for the oil tank which should extend a minimum of 300mm from each side of the tank (to stop weeds/grass growing too close to the tank and creating a fire risk).


(The current regulations state) that any new or replacement oil storage tanks should incorporate Secondary Containment (secondary containment means a double skinned (or ‘bunded’) tank, or a leak-proof containment pit under the tank that will hold a minimum of 110% of the tanks total contents). However, since 2002 a Domestic Oil Tank Risk Assessment has been available to check whether a single skinned Oil tank Installation would be deemed legal.

Single skinned (un-bunded) tanks are permitted as long as they are not:

  • Within 10 meters of controlled water (rivers, lakes, canals, the sea, ditches that may run off into rivers).

  • In a location where if a spillage occurred the oil will not enter any open drains or loose fitted (not sealed and fixed down) manhole or inspection covers to drains.

  • In a location where a hard surface or hard ground could enable an oil spillage to reach controlled water (including onto a road where there are rainwater drains or gullies).

  • Located where the vent pipe cannot be seen from the fill point (i.e. if a remote filling pipe is fitted).

  • Located in a ‘Groundwater source Protection Zone 1’ Click here for a map

  • Within 50 meters of a bore hole Click here for a map

Again, oil tanks should be fitted with a solid non-combustible base, suitable to carry the weight of a fully filled tank (to prevent listing and eventual spillage) and built in accordance with the manufacturer’s instructions (to prevent stress fractures occurring through inadequate support).


The owner of a domestic oil tank of less than 3501 litres cannot be forced to bring their installations in line with the current regulations, unless they move or replace the oil tank. However, your tank will need changing eventually - single skinned or bunded it is advisable to budget for your tank to be replaced at 20 year of age.


The Building Regulations and Control of Pollution Regulations 2002 includes that…

Any installation or movement of an Oil fired Appliance (includes an oil storage tank) in England and Wales requires a formal application for planning permission to the relevant Local Authority Building Control unless the Installer has the relevant registration with OFTEC (Oil fired Technical Association) or other recognised Competent Person Schemes that enables the Installer to Self-Certify their OWN work and register the installation with Local Area Building Control.


Any Domestic Oil Storage tank with a capacity of 3501 litres or more is classed as a Commercial or Non-Domestic installation and falls under the Control of Pollutions Regulations and Commercial Fire Regulations and therefore MUST incorporate a Bund for secondary containment of the fuel in the event of an Oil leak or overfill situation or it will be deemed an illegal installation, leaving the owner liable to prosecution with a fine of up to £20,000. In addition, any cost relating to damage or clean-up costs will be solely liable by the owner of the tank.

This short video from OFTEC explains your responsabilities.

This 'Blog' is designed only to give the most basic guide and should only be used as such. For full details please see the Building Regulations Approved Document J and BS5410 part 1, 2 & 3 and OFTEC Technical book 3 and any amendments made to them.

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