The Hierarchy of Controls is a structured framework used to eliminate, reduce, or manage workplace risks in a logical and prioritised way. Rather than treating all risk control measures as equal, the Hierarchy of Controls ranks controls from most effective to least effective. When applied correctly, it assists organisations to reduce risks, prevent incidents, and improve compliance.
What is the Hierarchy of Controls?
The Hierarchy of Controls is a structured approach used to determine how workplace risks should be managed or controlled. It ranks control measures in order of effectiveness.
The five levels are:
1. Elimination: Remove the hazard entirely
2. Substitution: Replace the hazard with something safer
3. Engineering controls: Isolate people from the hazard
4. Administrative controls: Change the way work is performed
5. Personal Protective Equipment (PPE): Protect the individual worker
The higher the control appears on the list, the more effective or reliable it is at preventing harm. Controls at the bottom of the hierarchy depend heavily on human behaviour and are therefore less dependable as standalone solutions.
Why the order of controls matters
The Hierarchy of Controls is intentionally structured to list control measures from most effective to least effective. Organisations should strive to use the most effective risk control measures wherever reasonably practicable. This means that if a hazard can be eliminated, it should not simply be managed through the use of PPE. Relying only on PPE means that protection depends on workers wearing and using their PPE correctly every time. By contrast, eliminating the hazard removes the risk completely.
This structured prioritisation ensures that organisations do not default to the easiest solution, but instead consider the most effective one first.
Understanding each level of the Hierarchy of Controls
1. Elimination: Remove the hazard completely
Elimination means physically removing the hazard from the workplace. This is the most effective form of risk control because the risk no longer exists.
Example: During a safety inspection, it is discovered that a redundant cutting machine with an exposed blade is still stored on the workshop floor. Rather than fencing it off or posting warning signs, the organisation removes the machine entirely from the workspace.
2. Substitution: Replace the hazard with something safer
When elimination is not possible, substitution involves replacing the hazard with a less dangerous alternative.
Example: A cleaning solvent produces strong fumes that irritate workers’ lungs. The organisation switches to a non-toxic, water-based product that performs the same function but significantly reduces exposure risks.
3. Engineering controls: Isolate people from the hazard
Engineering controls change the physical workplace environment to reduce workers’ exposure to identified risks. Engineering controls are highly effective because they do not rely solely on workers remembering to follow safety instructions.
Example: In a warehouse where forklifts and pedestrians share space, the company installs fixed barriers and clearly separated walkways, thereby physically separating workers from dangerous moving machinery.
4. Administrative controls: Change how work is done
Administrative controls adjust policies and procedures, and introduce training to reduce exposure to risks. These may include:
- Rotating shifts to reduce time exposed to noise
- Introducing safe work procedures
- Providing health and safety training
- Displaying warning signage
Example: In an office environment where repetitive strain injuries are increasing, the organisation implements an ergonomics programme, including ergonomics training for all employees.
5. Personal Protective Equipment (PPE): Last line of defence
PPE includes items such as gloves, safety goggles, helmets, respirators, and protective footwear. PPE is essential in many environments, but it should not be the primary risk control in place if higher-level controls are feasible.
Example: Workers handling hazardous chemicals wear respirators or masks to prevent them from inhaling toxic fumes. A more effective control would be substituting hazardous chemicals for non-toxic substances, however, where this is not possible, PPE is used.
How the Hierarchy of Controls fits into risk assessments and HIRA
The Hierarchy of Controls is an important tool in a Hazard Identification and Risk Assessment (HIRA) process. Once hazards are identified and risks evaluated, the Hierarchy of Controls provides a useful framework for selecting the most appropriate and effective control measures. Instead of simply asking, “What protective gear do we need?” the first question becomes, “Can we eliminate or substitute this hazard first?” This mindset process results in more reliable risk control measures in the workplace.
How applying the Hierarchy of Controls improves compliance and long-term health and safety
The Occupational Health and Safety Act requires employers to eliminate hazards and reduce workplace risks as far as reasonably practicable. The Hierarchy of Controls provides a structured framework for demonstrating that the employer has implemented the most effective and reliable control measure possible.
From a compliance perspective, documentation showing that elimination, substitution, or engineering solutions were evaluated shows that an organisation has performed due diligence.
The benefits of using the Hierarchy of Controls go well beyond compliance. Applying the framework properly:
- Reduces workplace injuries
- Lowers compensation and insurance costs
- Improves operational efficiency
- Builds employee trust
- Strengthens the organisation’s overall health and safety culture
Learn how to identify workplace hazards, assess risks, and implement controls by attending HIRA training.
The Hierarchy of Controls is a powerful risk management tool frequently used to identify appropriate control measures during risk assessments. In our one-day HIRA (Hazard Identification and Risk Assessment) training, we teach delegates the skills needed to identify hazards, evaluate and prioritise risks using a risk matrix, suggest control measures, and document their findings. Regularly conducting comprehensive, logical risk assessments not only improves your compliance status, it also makes your workplace fundamentally safer for everyone.
Find out more about our HIRA training here or contact us to book your spot.