Feed trucks move a lot of product, but the part of the vehicle that gets the most attention during an audit is often the outside of the tanker. A facility that asks "what counts as clean?" usually discovers that its current answer is "the driver says it looks clean." That answer does not survive a customer inspection, a veterinary audit, or an internal investigation after a disease concern. Setting written acceptance criteria for the exterior of feed transport trucks is one of the lower-cost biosecurity controls a feed mill, cooperative, or integrated farm group can put in place, and it changes the conversation from opinion to evidence.
Why the exterior needs its own criteria
Most feed operations already have rules for the cargo compartment: swept, washed, dried, sometimes disinfected, always documented. The chassis, wheels, wheel arches, mudguards, tank exterior, chute and the areas behind the fenders get much less definition, even though those surfaces travel between farms and can carry mud, spilled feed, and organic residue into clean zones. Acceptance criteria for the exterior exist for the same reason interior criteria do: they define when a truck is allowed to move on to the next task, and they give the person checking the truck something concrete to look at.
A useful set of criteria also protects the wash area itself. Without a defined standard, trucks leave while still wet and dirty, the wash bay drains get loaded with feed and mud, and the next truck starts in worse condition than the last one.
Start with the surfaces, not the method
Write the criteria surface by surface. A practical list for a feed tanker usually covers:
Wheels, tyres, rims and the inside face of the wheel arches
Chassis rails, cross members and the area around the axles
Tank or body exterior, including the underside of the tip and the discharge chute
Mudguards, step plates, ladders and handrails
Cab step wells and the driver entry area, which tracks barn and yard traffic
For each surface, decide what "acceptable" means in observable terms: no visible caked mud, no loose feed residue, no standing organic material in the arches, no film that a hand or a wipe would transfer. Then decide how each item is checked — visual inspection, a tactile check, a wipe of a defined area, or a photograph saved with the trip record.
Make the criteria observable and repeatable
Criteria that rely on adjectives like "thorough" fail in practice. Three things make them hold up:
A reference standard: photographs of an accepted truck, taken at each surface, pinned up where the wash happens. New drivers and wash staff calibrate against the same images.
A defined check point: who inspects, at what stage (before disinfection, after drying), and what happens when an item fails — re-wash the zone, then re-check, not a note in a logbook.
A record: truck number, date, wash location, inspector, pass or fail by surface. This is what lets you see that one shift or one truck consistently fails the wheel arches.
Match the criteria to the cleaning equipment you actually run
Acceptance criteria must be achievable with the equipment on site. If the yard only has a cold-water pressure lance, do not write a standard that assumes a hot, low-volume steam process; if the standard requires removal of caked feed and grease from chassis components, then specify the temperature and pressure capability the wash equipment must deliver. That is also the point at which truck steam cleaning equipment becomes relevant to the specification: high-temperature, low-volume processes soften bonded organic residue on chassis and tank surfaces without the water volumes and runoff of continuous high-flow washing, which matters in a yard where drainage and effluent handling are constrained.
PowerDe's fixed unit, PowerDe HW02 steam cleaner, is a 220 V unit with dry and wet steam modes, a stainless tank and a water gun with nozzle, positioned for vehicle exterior cleaning at stations and parking facilities. Its published parameters (heating power, steam temperature and vapor pressure) are exactly the kind of figures you place in your criteria so that the process being bought matches the standard being asked for. Confirm current specifications with the manufacturer, because the published values should be checked against the model and configuration you would order.
Write the pass/fail rules in one page
A workable criteria sheet is short. For each surface it states: what must be absent, how it is checked, and what the acceptable evidence is. It then states the release rule — the truck may enter the farm, the mill yard, or the clean zone only when all listed items pass, and any fail sends the vehicle back to a named re-clean step. Add a line on who is authorised to sign the release, so that time pressure from dispatch does not quietly lower the bar.
Pilot on one route, then adjust
Roll the criteria out on the route with the dirtiest trucks first. Run it for a few weeks, keep the fail records, and look at which surfaces fail most and whether the wash cycle is actually capable of clearing them. That evidence tells you whether to change the process, buy capability, or tighten the interval between washes. A set of acceptance criteria that has been revised once from real data is worth far more than a document that nobody has tested.
Common mistakes to avoid
Writing criteria only for what is visible from the cab, and skipping the arches, chutes and chassis.
Setting a standard the current equipment cannot reach, then quietly ignoring failures.
Inspecting before the truck has dried, which hides residue and gives a false pass.
Recording only overall pass/fail, which leaves no way to find the recurring problem surface.
For a feed operation, the exterior standard is part of the same chain as interior cleaning and traffic control. Define it, equip it properly, and check it the same way every time, and it becomes one of the controls you can actually defend in an audit. A supplier of commercial steam cleaning equipment can be brought into that conversation early, at the specification stage, rather than after the criteria have already been written around inadequate equipment.
