Empty IBCs are everywhere: on farms, at depots, on the back of classified ads. It's tempting to rinse one out and use it for AdBlue®, either to decant bulk product or as a spare storage tank. It looks like a sensible saving. In practice, it's one of the most common routes for contamination, and the savings are small compared with what can go wrong.
Residue you can't wash out
AdBlue has extremely tight purity limits. Under ISO 22241-1, metals such as copper and zinc are limited to 0.2 mg/kg, and calcium, iron, magnesium, sodium and potassium to 0.5 mg/kg each. Insoluble matter is limited to 20 mg/kg. Those are tiny amounts, and a reused IBC can exceed them easily.
- Plastic absorbs. HDPE is a good material for AdBlue, but it can take up small amounts of what it previously held, particularly oils, solvents and some chemicals. That residue can leach back out into the next contents.
- Films and sediment cling. Oily films, surfactants and fine sediment stick to the inside walls and corners, and are very hard to reach through a top lid.
- Valves and gaskets hold on. Old product sits in the valve body and gasket, where rinsing rarely reaches it.
Previous contents aren't always what the label says, either. A second-hand IBC may have been refilled several times with different products, and old labels are often left on or peeled off.
If the IBC held diesel, oil, coolant, detergent, fertiliser or an unknown chemical, it shouldn't be used for AdBlue. Full stop.
Rinsing often makes it worse
Most people rinse a second-hand IBC with a hose. Tap water contains calcium, magnesium and other minerals far above the levels AdBlue allows. Water left in the bottom also dilutes the urea. So even an IBC that held something harmless can end up contaminating the AdBlue simply through the way it was cleaned.
Detergents bring their own problems: they leave surfactant residue and often sodium or phosphate, both of which are limited in the AdBlue specification.
What about an IBC that held AdBlue?
This is lower risk than an IBC from another product, but it still isn't a clean container. Once it has been emptied and opened:
- Dust and moisture get in through the open lid and valve.
- Any AdBlue left in the bottom dries to urea crystals and may have been sitting hot.
- The bottle may be sun-aged after months outside, and the valve and seals worn.
- Tamper seals are gone, so there is no way to know what else has been in it.
A clean IBC for AdBlue should be dedicated to AdBlue, sealed, with intact tamper seals, a clean valve and no residue, odour or discolouration. A used one no longer meets that description.
Weighing up the cost
The saving from reusing an IBC is the cost of the container. The downside is a batch of contaminated AdBlue going into your fleet. That can mean blocked filters and injectors, damage to the SCR catalyst, fault codes and reduced power until the problem is fixed. A single catalyst repair can cost far more than a lifetime of new IBCs, and a fleet-wide contamination event means vehicles off the road while it's sorted out.
Reconditioned IBCs, which are washed and fitted with new valves, reduce some of these risks. The bottle's history is still unknown, though, and general washing processes aren't designed around AdBlue's purity limits.
There is also a traceability cost. With a sealed IBC from a licensed producer, you have a batch number and can get a Certificate of Analysis. With a refilled second-hand container, if something goes wrong you have no way of showing where the problem started.
A practical alternative you can set up today: if you're reusing IBCs because you buy bulk and need somewhere to put it, look at a dedicated on-site tank instead. If it's because a full IBC is more than you need, smaller packs such as 210 L drums may suit better. Either way, mark any second-hand IBC on site as not for AdBlue so it can't end up in use by accident.
How Liquidia can help
Liquidia supplies AdBlue in new, sealed 1,000 L IBCs with intact tamper seals, as well as bulk delivery into dedicated on-site tanks for sites that use larger volumes.