How is AdBlue made?

How is AdBlue made?

How is AdBlue made a guide by Stephen Buckley, Sales Manager, Fleetmaxx Solutions Burnley

If you run diesel vehicles, you’ve almost certainly heard of AdBlue® — that clear, unassuming liquid that keeps your fleet compliant, your engines clean, and our air that little bit fresher. But have you ever wondered how it’s actually made?

At Fleetmaxx Solutions, we don’t just supply AdBlue® — we manufacture our own, right here in the UK, under the name FleetBlue. So, let’s lift the lid on what goes into making this vital fluid and why quality matters more than you might think.

What is AdBlue®?

AdBlue® — sometimes called Diesel Exhaust Fluid (DEF) — is the magic ingredient that helps modern diesel engines meet strict Euro 6 emissions standards.
It’s a simple but powerful mix: 32.5% high-purity urea and 67.5% de-ionised water. When injected into a vehicle’s exhaust system, it reacts with nitrogen oxides (NOx) to produce harmless nitrogen and water vapour — reducing harmful emissions that damage both health and the environment.

Step 1: How is AdBlue made?: Producing the urea

Urea doesn’t come from the farmyard anymore — it’s made synthetically.
Manufacturers combine ammonia and carbon dioxide under controlled pressure and temperature to form pure urea crystals. These are then melted and filtered to create a solution clean enough for automotive use.
Any trace of impurity here could damage your vehicle’s Selective Catalytic Reduction (SCR) system — which is why quality control starts right at the source.

Step 2: How is AdBlue made?: Purifying the water

Ordinary tap water just won’t cut it.
To produce AdBlue®, we use de-ionised or de-mineralised water, purified through ion-exchange resins to remove minerals and contaminants. This process ensures the water is as pure as possible — because even tiny traces of metal ions can shorten catalyst life or trigger costly maintenance issues.

Step 3: How is AdBlue made?: Precision blending

The two ingredients are then blended in exact proportions — 32.5% urea to 67.5% water — the sweet spot that ensures AdBlue® performs correctly in all temperatures.
The solution is gently mixed, tested for conductivity, and constantly monitored for consistency. In FleetBlue’s UK plant, every batch undergoes rigorous checks before leaving the production line.

Step 4: How is AdBlue made?: Testing and quality control

AdBlue® must meet the ISO 22241 standard, a strict global benchmark that governs everything from urea concentration to impurity thresholds.
Only products that pass these tests are licensed to carry the AdBlue® trademark, owned by the German Association of the Automotive Industry (VDA).
It’s the difference between a trusted product that protects your SCR system — and an inferior one that could cost you dearly.

Step 5: How is AdBlue made?: Storage and delivery

Once blended and certified, AdBlue® is stored in sealed tanks and distributed in containers, drums, IBCs, or bulk tankers, depending on customer needs.
FleetBlue’s own production and logistics network means we can supply businesses across the UK quickly, cost-effectively, and — most importantly — with complete confidence in the purity of the product.

Why purity matters

Off-specification water or contamination at any stage of production can clog injectors, damage catalysts, or trigger dashboard warnings. That’s why buying from a trusted manufacturer like Fleetmaxx Solutions makes all the difference.

Every litre of FleetBlue AdBlue® meets ISO 22241 standards — guaranteed.

A cleaner future, made locally

AdBlue® might not look like much, but it’s playing a huge part in cleaning up diesel emissions.

At Fleetmaxx Solutions, we’re proud to be doing our bit — manufacturing FleetBlue right here in the UK, supporting fleets nationwide with bulk tanks, containers in various sizes, drums, and telemetry Smart Tank systems to make AdBlue® management easy.

So next time you top up your tank, you’ll know exactly what’s inside — and that it’s helping your business stay compliant, efficient, and environmentally responsible.

Stephen Buckley, Sales Manager,

Fleetmaxx Solutions Burnley