Guide
The hierarchy of controls
Not every control measure is worth the same. The hierarchy of controls ranks them by how reliably they protect people, from removing the hazard altogether to protective equipment as the last line. This guide explains the five levels with real examples from our hazard library, and what UK law expects.
What is the hierarchy of controls?
The hierarchy of controls is the order in which to choose control measures, most effective first: eliminate the hazard, substitute something less harmful, use engineering controls such as guards and barriers, use administrative controls such as permits, training and supervision, and use personal protective equipment last. UK law builds the same order into the general principles of prevention, which put avoiding risks first and collective measures before individual ones.
Last updated . Facts checked by the SiteSurvey team on 24 October 2026 against Management of Health and Safety at Work Regulations 1999, Schedule 1, HSE: COSHH good practice, the hierarchy of control options, Work at Height Regulations 2005, regulation 6 and HSE: Managing risks and risk assessment at work.
The five levels at a glance
- 1. Eliminate
- Take the hazard away altogether, usually by doing the job a different way or from a different place.
- 2. Substitute
- Swap the hazard for something less harmful: a quieter tool, a cold-applied method, a smaller pack.
- 3. Engineering control
- Keep people away from the hazard with a physical measure: a guardrail, a barrier, extraction, isolation.
- 4. Administrative control
- Change the way the work is done: a permit, a check, training, supervision, timing.
- 5. Personal protective equipment
- Protect the person as the last line: a harness, hard hat, gloves or respirator. Never the only control.
Why the order matters
A control near the top of the hierarchy changes the work so the hazard is gone or smaller for everyone, every time. A control near the bottom depends on a person doing the right thing, every time, while the hazard is still there. Removing a fragile rooflight from the route protects the whole crew. A harness protects one person, and only if they clipped on, to a rated anchor, with a rescue plan behind it.
That is why the general principles of prevention in Schedule 1 of the Management of Health and Safety at Work Regulations 1999 begin with avoiding risks and combating them at source, include replacing the dangerous with the non-dangerous or less dangerous, and give collective protective measures priority over individual ones. HSE's guidance on hazardous substances describes the same thing as a broad hierarchy ranked by reliability and effectiveness, says to always consider elimination first, and calls PPE the final control option. The Work at Height Regulations 2005 put it in three words: avoid, prevent, minimise.
The hierarchy does not mean you only use one level. Most real jobs need several: a scaffold with guardrails (engineering), a seven-day inspection and a permit (administrative) and hard hats in the zone below (PPE). It means you look from the top down, use the higher levels as far as is reasonably practicable, and do not rely on the lower ones alone.
Each level, with examples from real hazards
The examples are controls from our library of 25 hazards and 135 controls, the same ones the RAMS form offers as a tick list.
Take the hazard away altogether, usually by doing the job a different way or from a different place.
Do the work from the ground or inside the building instead
Excavation and underground services
Route changed to avoid the services or the excavation
Materials delivered to the point of use or moved by hoist, trolley or telehandler
Supply isolated, locked off and proved dead before work starts
Swap the hazard for something less harmful: a quieter tool, a cold-applied method, a smaller pack.
Loads broken down or smaller packs ordered
Slips, trips and falls on the level
Cordless tools so there are no trailing leads
Battery tools, or 110 V centre tapped to earth on construction sites
A less harmful product chosen where one does the job
Keep people away from the hazard with a physical measure: a guardrail, a barrier, extraction, isolation.
Tower, MEWP or scaffold with guardrails and toeboards rather than ladders
Exclusion zone below the work, fenced and signed
Excavation and underground services
Sides supported or battered back before anyone enters
Slips, trips and falls on the level
Leads and hoses run at high level or covered where they cross routes
Change the way the work is done: a permit, a check, training, supervision, timing.
Ladders only for short, light work with three points of contact
Tools tethered and materials kept back from the edge
Excavation and underground services
Service plans obtained and the area scanned with a CAT and Genny before and during digging
Two-person lifts for heavy or awkward items
Protect the person as the last line: a harness, hard hat, gloves or respirator. Never the only control.
Harness and lanyard clipped to a rated anchor where guardrails are not possible
Hard hats worn by everyone inside the zone
Slips, trips and falls on the level
Safety boots with a good grip worn
Insulating gloves and eye protection for live testing
Try it
See the hierarchy on a real hazard
Pick a hazard and tick controls. The bar shows which levels you have reached; tick only protective equipment and you get the same warning the RAMS form gives.
Interactive
Try it: choose the controls for a hazard
Works the same way as the RAMS form. Nothing you tick is saved or sent anywhere.
Your controls, by level
- Eliminatenot ticked
- Substituteno control at this level for this hazard
- Engineeringnot ticked
- Adminnot ticked
- PPEnot ticked
Nothing ticked yet.
3. Score the risk with these controls
Applying it on a job
Take each hazard in turn and start at the top. Ask whether the work can be done without the hazard at all: from the ground, from outside the confined space, with the supply dead, before the public arrive. If it cannot, ask whether something less harmful does the job: a cold-applied membrane instead of a torch, a quieter tool, smaller packs. Then put physical protection in place, then the permits, checks, training and supervision, and finally the protective equipment for what is left.
Write down what you chose and why the higher levels were not reasonably practicable where you skipped them. A principal contractor reading your RAMS will look for exactly that. In the SiteSurvey RAMS template, each hazard offers its controls as a tick list grouped by this order, asks how they apply on your job, and warns when protective equipment is the only control ticked. See how suggested controls work or what a control measure is.
Common questions
Is the hierarchy of controls a legal requirement?
The order is. Schedule 1 of the Management of Health and Safety at Work Regulations 1999 sets out the general principles of prevention, starting with avoiding risks, then combating them at source, replacing the dangerous with the less dangerous, and giving collective protective measures priority over individual ones. Specific regulations repeat it: the Work at Height Regulations say avoid, then prevent, then minimise, and COSHH guidance calls PPE the final control option.
Do I have to start at the top for every hazard?
You have to consider the top first. If the hazard can reasonably be removed or replaced, that is the answer. If not, you work down, and most jobs end up with a mix: a guardrail and a check and a harness, for example. What you should not do is go straight to PPE because it is quickest. The test the law uses is what is reasonably practicable, balancing the risk against the time, trouble and cost of each measure.
Why is PPE at the bottom when it is so widely used?
Because it only protects the person wearing it, only when it fits, is worn properly and is in good condition, and it does nothing to the hazard itself. A guardrail protects everyone near the edge without anyone having to remember anything. That is also why the SiteSurvey RAMS form warns you when the only control ticked for a hazard is protective equipment.
What is the difference between an engineering control and an administrative control?
An engineering control is physical and works without people having to do anything: a guardrail, a barrier, local exhaust ventilation, an interlock, isolating and locking off a supply. An administrative control changes how people work: a permit, a method statement, a check, training, supervision, signs, limiting time on a task. Engineering controls rank higher because they do not depend on someone following an instruction every time.
Hazards in the library
Library
Every hazard and its controls
25 hazards, 135 controls, each placed in the hierarchy.
Hazard
Working at height
Avoid, prevent, minimise: the hierarchy written into the law.
Hazard
Confined spaces
Where elimination, staying out, comes first by law.
Feature
Suggested controls
The tick list in the RAMS and risk assessment forms.
Controls in the right order, on every RAMS.
The RAMS template offers each hazard's controls from eliminate to PPE, and flags a hazard that relies on PPE alone.