What is the hierarchy of controls, and how should it be applied?

The hierarchy of controls is an essential framework in occupational health and safety (OHS) designed to effectively reduce or eliminate exposure to workplace hazards. This framework provides organisations with a clear roadmap for safeguarding their employees against potential risks. By ranking control measures based on their effectiveness, the hierarchy highlights the most impactful methods at the top and the least effective ones at the bottom.

Central to this approach is the focus on tackling hazards at their source rather than depending solely on individual behaviour or protective equipment. By adopting this organised strategy, organisations can significantly improve workplace safety while also implementing long-term and effective risk-reduction measures. This proactive approach not only ensures worker protection but can also enhance productivity and boost morale, as employees feel more secure and appreciated in their work environment. Furthermore, embracing the hierarchy of controls cultivates a safety-oriented culture within the organisation, promoting ongoing improvement and vigilance in managing hazards.

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The Hierarchy of Controls Explained

1. Elimination

   • Definition: Removing the hazard entirely from the workplace, eliminating any associated risks.
   • Example: Replacing manual heavy lifting tasks with automated machinery.
   • Effectiveness: Most effective as it removes the hazard completely, but often challenging due to feasibility or cost.

2. Substitution

   • Definition: Replacing a hazardous material, process, or activity with a safer alternative.
   • Example: Using water-based paint instead of solvent-based paint to reduce exposure to toxic fumes.
   • Effectiveness: Highly effective but requires careful consideration to ensure the substitute does not introduce new risks.

3. Engineering Controls

   • Definition: Physically isolating people from the hazard or altering the work environment.
   • Example: Installing guards on machinery or adding ventilation systems.
   • Effectiveness: Reduces risk at the source and does not rely on worker behaviour, making it more reliable than administrative controls or PPE.

4. Administrative Controls

   • Definition: Implementing policies, procedures, or training to reduce exposure to hazards.
   • Example: Rotating workers to minimise repetitive strain injuries or conducting safety training programs.
   • Effectiveness: Relies on consistent adherence by workers, making it less effective than elimination or engineering controls.

5. Personal Protective Equipment (PPE)

   • Definition: Providing workers with protective gear to reduce exposure to hazards.
   • Example: Hard hats, gloves, eye protection, or respiratory masks.
   • Effectiveness: Least effective as it depends entirely on proper use and maintenance by workers. Should be used as a last line of defense.

 

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How to Apply the Hierarchy of Controls

1. Assess the Hazard

   • Identify and evaluate the nature, likelihood, and severity of the hazard.
   • Use risk assessments to prioritise hazards that require immediate action.

2. Select Control Measures

   • Start at the top of the hierarchy (elimination) and work downwards.
   • Consider combining controls for more comprehensive risk reduction (e.g., engineering controls with administrative measures).

3. Implement Controls

   • Ensure proper installation or enactment of the chosen measures.
   • Provide training and support for new processes or equipment.

4. Monitor Effectiveness

   • Regularly inspect and test controls to ensure they remain effective.
   • Gather feedback from workers to identify potential gaps or unintended consequences.

5. Review and Adapt

   • Update controls in response to new hazards, operational changes, or incidents.
   • Continuously seek opportunities to move higher in the hierarchy.

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Practical Application Examples

• Noise Control:

  • Elimination: Cease operations causing excessive noise.
  • Substitution: Use quieter machinery.
  • Engineering Controls: Install soundproof enclosures.
  • Administrative Controls: Limit time spent in high-noise areas.
  • PPE: Provide hearing protection devices.

• Chemical Hazards:

  • Elimination: Discontinue use of harmful chemicals.
  • Substitution: Use non-toxic alternatives.
  • Engineering Controls: Install fume hoods.
  • Administrative Controls: Establish protocols for safe handling.
  • PPE: Provide gloves and respirators.

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Summary

The hierarchy of controls is a systematic approach to reducing workplace hazards.

The hierarchy prioritises elimination, substitution, and engineering controls ahead of administrative measures and personal protective equipment (PPE). This organised framework not only assists organisations in effectively managing risks but also highlights the critical importance of addressing hazards directly at their source. By methodically navigating through the hierarchy, businesses can pinpoint the most effective strategies for risk reduction, leading to sustainable solutions that are less dependent on individual behaviours.

At the top of this hierarchy, elimination emphasises the vital goal of achieving a hazard-free environment whenever feasible. Substitution motivates organisations to explore safer alternatives, which, in turn, encourages innovation and ongoing enhancements in work processes. Engineering controls contribute to safety by establishing physical barriers between workers and potential hazards, thereby significantly diminishing exposure risks.

While administrative controls and PPE are crucial elements of a comprehensive safety program, they function as supplementary measures to be employed only after higher-level controls have been thoroughly evaluated. This methodology not only fosters a culture of safety within the workplace but also empowers employees by actively involving them in the identification and mitigation of risks.

Implementing this hierarchy enables organisations to prioritise sustainable solutions that align with occupational health and safety regulations while simultaneously boosting overall productivity and employee morale. A safer work environment leads to reduced absenteeism, lower healthcare costs, and heightened job satisfaction, resulting in a mutually beneficial situation for both employers and employees. Consequently, adopting the hierarchy of controls transcends mere regulatory compliance; it represents a strategic commitment to cultivating a resilient and safety-focused workplace culture.

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FAQ: What Is the Hierarchy of Controls, and How Should It Be Applied?

1. What is the hierarchy of controls?

The hierarchy of controls is a structured framework used in occupational health and safety (OHS) to manage and reduce workplace hazards.
It ranks control measures from most to least effective, guiding organisations to eliminate risks at their source rather than relying on worker behaviour or personal protective equipment (PPE).

This framework is referenced in:

• WHS Regulations 2011 – Regulation 36, which requires duty holders to apply the hierarchy when managing risks.

• ISO 45001:2018 – Clause 8.1.2, which emphasises eliminating hazards and applying controls according to effectiveness.

Tip: Always start at the top of the hierarchy—elimination and substitution deliver the most sustainable safety improvements.

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2. Why is the hierarchy of controls important?

It provides a systematic and defensible approach to risk management that:

• Prioritises proactive, sustainable controls.

• Reduces dependence on individual behaviour.

• Supports regulatory compliance and due diligence.

• Improves safety culture, trust, and morale.

By following the hierarchy, organisations can ensure that controls are both effective and aligned with long-term safety objectives.

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3. What are the five levels of the hierarchy of controls?

1. Elimination

Definition: Remove the hazard completely from the workplace.
Example: Replace manual handling with automated lifting.
Effectiveness: Most effective, as it removes risk entirely.
Limitation: May not always be practical due to operational constraints.

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2. Substitution

Definition: Replace the hazardous process or material with a safer alternative.
Example: Use water-based paint instead of solvent-based.
Effectiveness: Highly effective, but must ensure the substitute doesn’t introduce new hazards.

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3. Engineering Controls

Definition: Design or modify equipment, processes, or the workplace to isolate people from hazards.
Example: Install machine guards or ventilation systems.
Effectiveness: Reliable and consistent, as it reduces exposure without relying on worker behaviour.

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4. Administrative Controls

Definition: Implement work methods, policies, and training to reduce exposure.
Example: Job rotation, safety signage, or procedural changes.
Effectiveness: Moderately effective, but depends on consistent compliance.

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5. Personal Protective Equipment (PPE)

Definition: Provide protective clothing or equipment to reduce harm if exposure occurs.
Example: Helmets, gloves, eye protection, respirators.
Effectiveness: Least effective because it relies entirely on correct use and maintenance.

Caution: Avoid over-reliance on PPE—it’s a last line of defence, not a substitute for hazard control.

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4. How should the hierarchy of controls be applied?

1. Assess the Hazard

• Identify hazards and evaluate their likelihood and potential severity.

• Prioritise significant risks using a structured risk assessment process.

2. Select Control Measures

• Start at the top of the hierarchy and work down.

• Combine controls where appropriate (e.g. engineering + administrative).

3. Implement Controls

• Plan for installation, communication, and worker training.

• Integrate into operating procedures and supervision practices.

4. Monitor Effectiveness

• Inspect and review controls regularly.

• Gather worker feedback to detect gaps or unintended risks.

5. Review and Adapt

• Reassess when there are changes in processes, incidents, or new technology.

• Aim to move higher in the hierarchy over time.

Caution: Don’t dismiss higher-level controls due to cost or complexity—these often deliver long-term savings and risk reduction.

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5. Can multiple levels of control be used together?

Yes. Combining controls provides layered protection and accounts for potential failures.
For example:

• Install ventilation (engineering)

• Limit exposure times (administrative)

• Provide respirators (PPE)

Tip: Integrate multiple controls to build redundancy and resilience into your safety system.

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6. What are some practical examples of applying the hierarchy?

Noise Control Example

Level	Control	Example
Elimination	Stop or redesign noisy process	Remove high-noise tasks entirely
Substitution	Use quieter machinery	Replace pneumatic tools with electric ones
Engineering	Install soundproofing or enclosures	Add acoustic barriers
Administrative	Limit time in noisy areas	Rotate workers, schedule breaks
PPE	Provide hearing protection	Issue earplugs or earmuffs

Chemical Hazard Example

Level	Control	Example
Elimination	Cease use of hazardous substance	Discontinue toxic chemical use
Substitution	Replace with safer alternative	Use biodegradable cleaning agent
Engineering	Isolate or ventilate	Install fume extraction
Administrative	Implement safe work procedures	Training, labeling, storage rules
PPE	Supply gloves and respirators	For residual exposure

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7. How does this align with ISO 45001 and WHS laws?

Applying the hierarchy of controls supports compliance and continual improvement through:

• ISO 45001 Clause 8.1.2: Emphasises elimination and control hierarchy.

• WHS Regulation 36 (Model): Requires duty holders to implement the highest reasonably practicable control.

• WHS Act Section 19: Mandates providing safe systems of work.

By embedding the hierarchy in your risk management and incident response processes, you demonstrate both due diligence and commitment to worker consultation under the WHS framework.

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8. What are the benefits of using the hierarchy of controls?

• Reduced risk exposure through targeted hazard control.

• Increased worker confidence and morale.

• Improved productivity from safer, more efficient processes.

• Lower long-term costs by preventing injuries and reducing reliance on PPE.

• Stronger safety culture through proactive hazard management.

Tip: Embedding the hierarchy into every risk assessment helps normalise safe decision-making at all levels of your organisation.