Multiple liquids on a single rack: switching safely from irrigation water to preservative (cleaning, labelling, prevention of cross-contamination)

Multiple liquids on a single rack This is everyday life on a farm and in property maintenance: the same IBC container and rack are used for everything from irrigation water to washing water and, as the seasons change, even for preserving agents. When equipment is used efficiently, the greatest risk lies not with the rack itself but with the process: what’s left in the container, what’s left in the valve, and what the next user finds at the end of the hose. This article outlines a practical procedure for safely switching from irrigation water to preservative – covering cleaning, labelling and the prevention of cross-contamination, step by step.

Lootu Oy (Kempele, Pekurinpolku 3, 90450 Kempele) manufactures sturdy IBC container racks for tractors and wheel loaders. Once the rack has been designed for practical use, the next step is to make liquid handling just as systematic as load securing: a clear process reduces errors and keeps work running smoothly even during the busiest season.

Why does “multiple liquids on a single rack” require a process?

An IBC container (container + valve + caps + any hoses and pumps) forms a single unit in which even a small amount of residue can be transferred to the next liquid. Irrigation water is often a “low-risk” liquid, but in the case of preservatives, liquid fertilisers and detergents, even minor contamination can cause production disruptions, damage to materials or safety risks. Therefore, in a “multiple liquids on a single rack” system, the entire flow path must be taken into account, not just the internal surface of the tank.

Cross-contamination typically occurs at three points: (1) residue and sediment left at the bottom of the tank, (2) “dead spaces” in valves and fittings, and (3) hoses and dispensers that are used interchangeably when in a hurry. If these areas are managed through a clear routine, the same rack can be reused seasonally without compromising on safety or quality.

If you’d like to read more about the versatile uses of IBCs on a farm, please also see our in-house article: An IBC container on a farm: a versatile solution.

Cleaning: what needs washing (not just the tank)

When switching from irrigation water to a preservative, the rule of thumb is: wash everything that comes into contact with the liquid, and everything that might be splashed on. Washing the inside of an IBC container is just the start. Valves, seals, couplings, caps, filling funnels, hoses, any filters and dispensers are often more critical than the “large surface area” of the container itself, as they contain structural recesses and tight gaps.

In practice, washing should be divided into two stages: (A) a quick intermediate wash when the liquid is changed within the same “risk category” (e.g. clean water → washing water), and (B) a thorough wash and disassembly of parts when switching from irrigation water to a preservative or other chemical. During thorough washing, remove the external parts of the valve as far as the manufacturer permits, and also rinse the internal parts of the connector separately. If you use cleaning agents, ensure they are compatible with the IBC’s plastic and sealing materials.

As a general rule, when it comes to chemical safety, it is advisable to refer to the manufacturer’s Safety Data Sheet (SDS) and follow best practice. The Finnish Institute of Occupational Health has compiled a set of basic principles for chemical safety, which are worth referring to when a new preservative or detergent is introduced into the workplace: Finnish Institute of Occupational Health: Chemical Safety.

When changing the fluid, the most important thing is to manage the “last metre”: the valve, the fittings and the hose. Residue tends to accumulate there, and that is where it ends up in the next tank.

Labelling and locking: how do you ensure you use the right fluid every time?

“Multiple fluids on a single rack” only works if the labelling is so clear that even a stand-in or a contractor can understand the situation at a glance. A mere piece of tape isn’t enough if it comes off in the rain or gets dirty. I recommend a three-tier labelling system: (1) a large label on the container (contents + risk category), (2) an “instruction tag” attached near the valve (specifying the target and the hose to be used), and (3) an entry in a notebook or digital log (date, user, whether flushing has been carried out, next permitted fluid).

It is also advisable to introduce a mechanical or operational locking system: a warning tag that locks onto the valve handle, colour-coded caps or connectors, or simply a “key policy” (e.g. the preservative hose is stored in a locked cupboard). This ensures that the wrong fluid is not accidentally dispensed into the wrong place. If the rack is used with several machines (a tractor and a wheel loader), the labelling must also be visible from a distance and from all sides of the tank.

When planning your labelling procedure, you should also take into account the overall safety of using the rack. This involves, for example, loading and securing – you can find useful background information on these topics on the Lootu Oy website: Transporting an IBC container safely on a tractor.

Prevention of cross-contamination: hoses, connectors and “dead spaces”

The “a separate route for each fluid” approach helps to prevent cross-contamination. Ideally, the preservative should have its own hose, its own connectors and its own dispenser. If this is not realistic, at the very least the critical parts (the end of the hose, the quick-connect coupling, the nozzle/dispenser and the valve connector) should be standardised and kept separate. It is often the last 20–50 cm of the hose that cause the most problems, as they get dirty and dry out easily.

“Dead spaces” refer to areas from which fluid will not drain out simply by draining the system: the internal channels of valves, T-branches, the recesses of quick-release couplings and filter cups. When switching from irrigation water to preservative, carry out a separate ‘connector flush’: disconnect the connector, rinse it separately and drain it dry. In practice, this can be a separate step that takes a few minutes but prevents the worst cases of contamination. Also, always keep absorbent material and splash protection close to the filling and draining points.

If you’d like to learn more about the practical aspects of using preservatives, please also read: The transport and dosing of preservatives in practice.

The exchange process step by step: irrigation water → preservative

When a process is documented, it becomes something that can be understood and measured. The model below is particularly suitable for farms where the same rack is used for everything from dust suppression and irrigation in the spring to the handling of preservatives in the autumn. The aim is for everyone to know what needs to be done, in what order, and according to what criteria the tank is “cleared” for the next liquid.

It’s a good idea to start the replacement process before you even begin washing: choose a place where wash water and splashes can be contained, and make sure you have the right protective equipment to hand. Even small splashes of preservatives can be a nuisance, and using the wrong detergent or following the wrong sequence of steps can compromise the seals. If you are unsure about the handling requirements for a chemical, refer back to the SDS and check for compatibility.

Finally, carry out a quick functional test before filling: check that the valve is tight, that the connector is securely fastened, and that you are definitely using the correct hose. In filling and draining systems, small details can make all the difference when it comes to the risk of leaks – read more about this here: Filling and emptying solutions for IBC containers.

Set-up and day-to-day routines: how to keep the stand and tank in good condition

When “multiple liquids on a single rack” is a standard operating procedure, maintenance is not a separate project but part of day-to-day operations. Splash areas and fixing points on the rack collect dirt, and chemical splashes can, in the long term, cause surface damage or increase the risk of slipping. Carry out a quick weekly check: welds, fastenings, any warping, and ensure that the container always fits onto the rack in the same way without having to be “forced” into place.

It is also a good idea to incorporate a “zoning of liquids” into your daily routines: where the preservative is filled, where the watering can is filled and where washing is done. When these areas are fixed, the correct equipment is always to hand (protective gloves, absorbent material, warning signs, spare hoses). This is particularly useful on farms in the Oulu region and in the conditions of Northern Finland, where the weather and dirt take a heavy toll on equipment.

If you’re considering which rack to choose or want to check the dimensions, take a look at Lootu Oy’s product pages and instructions. For example, Water tank for a tractor On this page, you will find examples of use and guidance on how to choose a rack, and, if required, Lootu can advise you on the solution best suited to your specific application (Kempele, Oulu, Vaasa, Joensuu, Kuopio, Liminka, Tyrnävä, Raahe, Kajaani, Kokkola).

Summary: If you want to switch safely from irrigation water to preservative, set up a changeover process: clean the “last metre” as well, make clear markings, and separate the hoses and connectors. This way, the same IBC container and Lootu rack can be used from one season to the next without unnecessary risks – and work runs smoothly even when things get busy.