The product identity and the hazard information required locally - and the specific requirements differ by jurisdiction.

Most workplace chemical regimes require a container of decanted or diluted product to identify the contents and convey the hazards, typically through pictograms and short hazard statements.

Many also require enough information to locate the full safety data sheet, and some specify precautionary statements.

Some regimes provide a lighter alternative for containers used entirely within one shift by the person who filled them, but that exemption is narrow and rarely applies to a cleaning trolley.

The safest approach is to label fully rather than rely on an exemption.

Establish the local requirement, because pictogram systems and wording obligations vary between markets even where the underlying classification is similar.

Because the labels do not survive the environment - and an illegible label is an unlabelled bottle.

Paper labels in wet areas, in washrooms and in kitchens become unreadable within days. Adhesive fails, ink runs, and the label peels.

Chemical contact accelerates it, and the labels most exposed to chemical are the ones on chemical bottles.

Handwritten labels fade and are often illegible from the start.

The fixes are straightforward: laminated or synthetic waterproof labels, printed bottles from the chemical supplier, or engraved and moulded markings.

Whatever is used, the audit question is whether every bottle in the building is legible today - not whether labels were applied when the bottles were issued.

No - colour conveys area or product family, not hazard information, and regulators expect the label.

Colour coding is a genuinely useful operational control. It prevents a washroom bottle being used in a kitchen and helps staff who do not share a first language.

What it does not do is tell anyone what the chemical is, what its hazards are, or what to do after an exposure.

The two work together: colour for area and product family, label for identity and hazard.

The colour scheme itself should be documented and trained, because an undocumented scheme is interpreted differently by each new member of staff.

Where colour is also used to indicate abrasive grade or dilution strength, those conventions must be reconciled, or the same colour will carry two meanings in one building.

A label set that mirrors the dilution station outlets, so the bottle filled at a given tap always carries the corresponding label.

Dilution stations dispense several products from labelled outlets. Supplying matching bottle labels means the operator has nothing to decide.

Most chemical suppliers provide these as part of a dilution system, often with printed bottles as an alternative.

Printed bottles are the most durable option, since the marking cannot peel off, though they tie the bottle to one product for its life.

Where bottles are refilled with different products, a labelling station with a small printer or a set of pre-printed waterproof labels keeps it manageable.

Build labelling into the refill routine rather than treating it as a separate task - the bottle should not leave the dilution area unlabelled.

Treat the contents as unknown, do not use them, and dispose of them safely rather than guessing.

An unlabelled bottle of clear liquid could be anything, including something that will react with whatever it is combined with next.

Smelling it to identify it is a genuinely bad idea and has caused injuries.

The correct handling is to isolate it, treat it as unknown hazardous waste, and dispose of it in accordance with the site's waste procedure.

Emptying it down a sink is not safe unless the contents are known.

Recurrence is the real problem: a site that finds unlabelled bottles regularly has a process failure at the dilution station, and the fix is there rather than in enforcement.

Yes - the marking has to survive the chemical it identifies, which ordinary marker ink usually does not.

Standard permanent markers are removed by solvents, and many are dissolved by the cleaning chemicals they are used to label.

Solvent-resistant markers are available and are the right choice where handwritten marking is used.

Label adhesives fail on wet, cold or oily bottles, and the label falls off in storage.

Synthetic label stock resists tearing and water where paper does not.

The test is simple and worth doing: apply the label, wipe it with the chemical it will identify, and see whether it survives. If it does not, it will not survive in service.

The employer, in practice - the obligation sits with whoever controls the workplace, and it is discharged through procedure and training.

Workplace chemical regimes generally place the duty on the employer to ensure containers are labelled and that staff understand what the labels mean.

That is discharged by providing labels, building labelling into the dilution procedure, training staff, and auditing.

Individual staff are responsible for following the procedure, but a process that depends on someone finding a label is a process that will fail.

Contract cleaning adds a wrinkle: the contractor brings the chemicals and the client controls the premises, and both usually have obligations. The contract should say who does what.

In audited environments - healthcare, food, education - unlabelled bottles are a recurring finding, and the corrective action is nearly always a process change at the point of dilution.