B100 in a square

Biodiesel (FAME) up to 100%, that is, fuel that may be entirely biodiesel. On a vehicle, a B100 square means it can use it.

What to do

Fill from a B100 nozzle only if your filler-flap label or manual shows B100.

What it looks like: The characters B100 in bold inside a square, black on white. It is the only four-character diesel symbol in CEN's list.
Where you find it: On the nozzle and dispenser of a pump that sells it, and next to the filler cap and in the manual of a vehicle labelled for it.
Kind: diesel-type fuel
Set by: EN 16942:2016+A1:2021, identifier for diesel-type fuels (a square), required by Directive 2014/94/EU Article 7; in the UK, SI 2019/421 Schedule 1, Part 2

Can my car use it?

“The information inside the shape indicates the maximum biofuel content in the fuel that is recommended for use by the vehicle that is equipped with the new label.”
— European Commission, New EU fuel marking: questions and answers (MEMO/18/6102)

“Vehicle manufacturers do not recommend fitting the labels to older vehicles. Please contact your local dealer if you need advice on which fuel is recommended for use in your vehicle.”
— ACEA, ACEM, ECFD, FuelsEurope and UPEI, Fuel labelling for road vehicles: information for consumers (PDF)

Check your vehicle's manual or the label inside the filler flap. We do not say which makes or models can use this fuel.

Official guidance:

In detail

CEN lists B100 as an EN 16942 diesel-type identifier, with diesel-type fuel quality laid down in EN 590, EN 16734, EN 16709 or EN 14214.
UK law allows for the four characters: the font may be smaller (at least 13 points instead of 14) 'in the case of a four character symbol' (SI 2019/421, Schedule 1, Part 2, paragraph 2(e)).
We found no public consumer guidance on where B100 is sold.

What it does not mean

It is not a diesel grade any diesel car can use, and it is not the same as XTL: B100 is FAME biodiesel, XTL is paraffinic diesel.

Labels that go with it

B30 in a squareDiesel containing up to 30% biodiesel (FAME). On a vehicle, a B30…XTL in a squareParaffinic diesel fuel: diesel made by synthesis or hydrotreatment…

Sources

Each document was fetched and read on the date shown; the clause or section is the one that sets or explains this label.

CEN-CENELEC: European Labels: Fuel — Diesel-type fuels (EN 16942 identifiers B7, B10, B20, B30, B100): identifier for diesel-type fuel; quality laid down in EN 590, EN 16734, EN 16709 or EN 14214 Checked 2026-09-29.
UK Government (legislation.gov.uk): The Alternative Fuel Labelling and Greenhouse Gas Emissions (Miscellaneous Amendments) Regulations 2019 (SI 2019/421) — Schedule 1, Part 2, paragraph 2(e)-(f): 'BX' where X is the maximum FAME content in volume percentage; minimum 13 points for a four-character symbol Checked 2026-09-29.