Follow one agency worker through a month and the problem stops being abstract. His payslip comes from the agency. His instructions come from whoever runs the floor that week. Those two organisations rarely speak about anything except hours and rates.
Week one: a packing hall
He starts on Monday at a food packer. The agency called him Friday afternoon. He gets a hi-vis, a badge and a five minute walk-through from a team leader with eleven other things to do. Nobody tells him which of the two doors is the emergency exit, because everyone else already knows.
Week three: a different address, different chemicals
The assignment ends early. On Wednesday he is at a chemicals warehouse. Different traffic plan, different PBM, different reporting line, different alarm. Nothing from week one transfers except the general habit of being careful, and nobody at site B knows what site A told him, because that record exists only in a folder at site A.
Three sites in a month is normal here. The instruction that matters is the part that changes at every gate, and that is exactly the part nobody owns.
Both legal systems point at the floor, not the office
In Belgium the split is written out. Codex art. X.2-11 puts the safety instruction specific to the workpost on the gebruiker (the user company), or the designated member of the hierarchical line: the risks there, the instructions for that workpost, and appropriate training in line with art. I.2-21. The agency office cannot deliver it, because it does not know the aisle.
The agency owns the record. Where a werkpostfiche (workstation record sheet) is required, and that is for workposts subject to compulsory health surveillance rather than every assignment, art. X.2-3 §2 makes the gebruiker draw it up; art. X.2-4 and X.2-5 make the agency complete its sections, keep a copy and hand a copy to the worker. Art. X.2-17 forbids both parties from placing a temp worker on a workpost with no fiche and no information given.
In the Netherlands the duty runs as a chain. Arbowet art. 5 lid 5 obliges the hirer to give the agency, in good time before the work starts, the description from its RI&E of the hazards and risk-limiting measures, so that the agency passes it to the worker. Waadi art. 11 repeats it on the agency side before the placement begins. The CAO voor Uitzendkrachten 2026-2028, art. 19, obliges the agency to inform the worker before the work starts about the required qualifications, the possible safety and health risks, and how to deal with them.
In both countries the person who knows the risk and the person who employs the worker are different people, and the law makes both of them act.
The figure that ends the discussion
The Nederlandse Arbeidsinspectie's Monitor Arbeidsongevallen 2024, published on 2 October 2025, found that in 18 percent of the investigated accidents the victim was an agency worker, while agency workers are roughly 4 percent of the working population. In industry it was almost 25 percent of victims against an estimated 8 percent of that sector's staff. Investigated accidents, not all accidents, and still the clearest argument for treating the first hour at a new address as the risky one.
Instruction that has to move with the worker
What this workforce needs is not a longer induction. It is short, site-specific instruction that reaches him before he arrives, in the language he reads, with a record both the agency and the client can produce.
Aristotl builds that from what you already hold: the site rules, the werkpostfiche content, the RI&E extract, the client's work instructions. Three to five minute courses on the worker's own phone, no laptop and no app installation, with a knowledge check, so a completion means something. Per client, per workpost and per version, separate from the general module he does once. When he moves to the next address he gets that site's course, not a repeat of the last one.
Pick one client site and one workpost. In a demo we build the instruction for it and show you the record on both sides of the split.