15 Jun What is the Hierarchy of Controls?
When it comes to protecting workers, not all safety controls are created equal. Many businesses make the mistake of relying too heavily on PPE or training alone, when more effective options may exist.
The Hierarchy of Controls is a structured approach used in New Zealand workplaces to manage risks by prioritising the most effective control measures first. Under the Health and Safety at Work Act 2015 (HSWA), businesses are expected to eliminate risks where reasonably practicable, or minimise them using the most effective methods available.
What is the Hierarchy of Controls?
The Hierarchy of Controls is a ranked system for controlling workplace hazards, ordered from the most effective to the least effective:
1. Elimination (Most Effective)
Completely remove the hazard from the workplace.
Examples:
- Removing a dangerous chemical from a process;
- Redesigning the task so workers do not need to work at height; or
- Replacing faulty equipment entirely.
Why it works:
If the hazard no longer exists, the risk is removed altogether.
2. Substitution
Replace the hazard with something safer.
Examples:
- Using non-toxic cleaning products instead of hazardous chemicals;
- Switching to quieter machinery; or
- Replacing manual lifting with mechanical aids.
Why it works:
Reduces the level of risk while maintaining productivity.
3. Isolation
Separate people from the hazard.
Examples:
- Machine guarding;
- Restricted access zones;
- Enclosed spray booths; or
- Physical barriers.
Why it works:
Prevents direct worker exposure.
4. Engineering controls
Use physical changes or equipment to reduce risk.
Examples:
- Ventilation systems;
- Safety interlocks;
- Fall arrest systems; or
- Automated processes.
Why it works:
Controls risk at the source rather than relying on worker behaviour.
5. Administrative controls
Change how work is done through policies and procedures.
Examples:
- Safe Operating Procedures (SOPs);
- Training;
- Signage;
- Job rotation;
- Fatigue management schedules; and/or
- Permit-to-work systems
Why it works:
Improves safety, but depends on workers consistently following procedures.
6. Personal Protective Equipment (PPE) (Least Effective)
Use equipment to protect workers.
Examples:
- Gloves;
- Helmets;
- Safety glasses;
- Respirators; and/or
- High-vis clothing.
Why it works:
Provides individual protection, but should only be used when higher-level controls cannot fully manage the risk.
Why is the Hierarchy of Controls important?
For businesses, the hierarchy helps ensure:
- Better legal compliance;
- Reduced workplace injuries;
- Lower long-term costs;
- Stronger safety culture; and
- More reliable risk reduction.
Relying only on PPE or policies often leaves businesses vulnerable because these controls depend heavily on human behaviour. Higher-order controls are generally more reliable and sustainable.
Here’s a practical example…
Hazard: Workers are exposed to dust from cutting concrete.
Applying the Hierarchy:
- Elimination: Use pre-cut materials.
- Substitution: Use lower-dust materials.
- Isolation: Restrict access to cutting area.
- Engineering: Install dust extraction systems.
- Administrative: Schedule cutting during low-traffic times.
- PPE: Provide respirators.
The more layers of control used, the stronger the protection.
Common mistakes businesses make
Many small businesses:
- Default straight to PPE;
- Skip proper risk assessments;
- Fail to review controls regularly;
- Over-rely on worker behaviour; and
- Neglect documentation.
This can increase both legal and operational risks.
How Hasmate helps businesses
Managing controls effectively can become complex, especially as your business grows. Platforms like Hasmate help businesses:
- Track hazards;
- Document control measures;
- Maintain SOPs;
- Manage corrective actions;
- Monitor compliance; and
- Keep records audit-ready.
This makes it easier to consistently apply the hierarchy while reducing compliance stress.
The Hierarchy of Controls is one of the most important foundations of effective workplace safety. By focusing on elimination and higher-level controls first, businesses can create safer workplaces, reduce incidents, and meet their obligations under New Zealand law.
If your business is serious about improving safety, understanding and applying the hierarchy correctly is essential. PPE should never be your first solution – it should be your final layer of defence.
Other suggested articles:
- How often should you review health and safety documentation?
- Training with Safe Operating Procedures
- Safe Operating Procedures to purchase
- What Should A Health and Safety Budget Include?
Please contact us if you would like to discuss.