Hierarchy of controls explained: what actually reduces risk on a factory floor

What is the hierarchy of controls?

The hierarchy of controls ranks workplace risk controls from most to least effective: eliminate the hazard first, then reduce risk through substitution, isolation or engineering controls, then administrative controls, with personal protective equipment (PPE) as the last resort. On a Victorian factory floor, the biggest safety gains come from acting as high up that list as reasonably practicable.

Why does the order matter?

Under the Occupational Health and Safety Act 2004 (Vic), employers have a duty to eliminate risks to health and safety, so far as is reasonably practicable. If elimination isn't reasonably practicable, the employer must reduce the risk, so far as is reasonably practicable (WorkSafe Victoria). The hierarchy of controls helps employers work through that duty systematically, starting with the most reliable option and only falling back to weaker controls when better ones genuinely aren't available.

What are the four levels of the hierarchy of controls?

1. Eliminate the hazard

The most effective control is removing the hazard entirely — not managing it, removing it. Examples include doing work at ground level instead of at height, or disposing of a chemical you no longer need. Elimination is cheapest and easiest to design in at the planning stage of a new process or layout, before equipment is bought and workflows are locked in (WorkSafe Victoria).

2. Reduce the risk — substitution, isolation, engineering

If you can't eliminate the hazard, the next tier is reducing the risk through:

• Substitution — swap the hazard for something safer, such as water-based paint instead of solvent-based paint, or a cordless drill instead of one with a power cord near moving parts.
• Isolation — physically separate people from the hazard, such as guard rails around holes, concrete barriers between pedestrians and forklifts, or remote controls for machinery.
• Engineering controls — physical or mechanical changes such as machine guarding, pedestrian-sensing systems, hoists for heavy loads, or speed-governing devices (WorkSafe Victoria).

3. Administrative controls

Administrative controls change how people work rather than the hazard itself — procedures for operating machinery safely, limiting exposure time to a hazardous task, or warning signage. They're a lower level of protection because they depend on people following them correctly, every time, under supervision (WorkSafe Victoria).

4. Personal protective equipment (PPE)

PPE — earmuffs, respirators, safety footwear, harnesses and the like — is the last line of defence. It only works if it's worn correctly and consistently, and it does nothing to control the hazard at its source. WorkSafe Victoria treats administrative controls and PPE as measures to use as a last resort, as an interim fix while a better control is introduced, or layered on top of higher-order controls for extra protection (WorkSafe Victoria).

Can you combine controls?

Yes — in practice, most real risk controls on a factory floor are combinations. WorkSafe Victoria's own example: protecting workers from flying debris on a concrete cutting saw might involve isolating the work area, guarding the saw blade, and using PPE such as face shields, all at once (WorkSafe Victoria). The hierarchy isn't a checklist you tick once and move on from — it's a decision framework for choosing the most effective combination that's reasonably practicable for your situation.

Who decides which controls to use?

The employer is responsible for selecting risk controls, but the OHS Act 2004 (Vic) requires consultation with employees and their health and safety representatives (HSRs), where they exist, before deciding on those controls (WorkSafe Victoria). Workers doing the job every day often know exactly where a machine guard gets in the way or where a procedure gets skipped under time pressure — that input changes what actually gets implemented, not just what looks good on paper.

Where this trips manufacturers up

The most common mistake I see on Victorian factory floors is jumping straight to PPE or a new sign because it's fast and cheap, without asking whether the hazard could have been isolated or engineered out instead. WorkSafe inspectors expect to see that higher-order controls were genuinely considered — not just PPE issued and forgotten. If you want a second set of eyes on how your current controls stack up against the hierarchy, book a site assessment.

FAQ

Is PPE ever an acceptable primary control? Only when it's genuinely not reasonably practicable to eliminate, substitute, isolate, engineer or administratively control the risk first, or as a temporary measure while a better control is put in place.

Does the hierarchy of controls apply to every hazard type? It's the general framework under the OHS Act 2004 (Vic) for physical hazards such as plant, noise, chemicals and manual handling. Victoria's new psychosocial hazard regulations use a similarly structured but differently worded hierarchy tailored to psychological risks.

Who created the hierarchy of controls? The hierarchy of controls model is promoted nationally by Safe Work Australia and adopted by WorkSafe Victoria as the standard approach for meeting the risk elimination and reduction duties in the OHS Act 2004 (Vic).

This article is general information for Victorian manufacturers, not legal advice. Last updated: 10 August 2026.