Understanding the Hierarchy of Control: A Practical Guide for High-Risk Work

Introduction

Workplace safety is a top priority in high-risk industries such as mining, oil and gas, manufacturing, and power generation. To effectively manage risks, organisations must follow a structured approach to hazard control. The hierarchy of controls is a framework used in industrial safety to prioritise risk reduction measures. It ranks strategies from most to least effective.

The hierarchy of control is more than just a guideline; it is an internationally recognized safety framework that helps companies prioritise risk mitigation by implementing the most effective control measures first. It forms the foundation of workplace safety regulations such as OSHA (Occupational Safety and Health Administration) and standards such as ISO 45001.

Understanding and correctly applying the hierarchy of control is crucial for process engineers, design engineers, safety managers, operations leaders, and frontline workers. When applied correctly, this framework can prevent accidents, improve compliance, and enhance overall workplace safety. However, many organizations fail to apply the hierarchy effectively—often skipping steps and relying too heavily on personal protective equipment (PPE) instead of eliminating hazards as early as possible in the design and operation of a facility.

In this guide, we’ll break down the five levels of the hierarchy of control, explore real-world examples, and explain how IntelliPERMIT’s digital safety solutions help organisations implement effective risk control measures.

What is the Hierarchy of Control?

The hierarchy of control is a systematic approach used to manage workplace hazards by prioritising risk reduction measures throughout the lifecycle of the facility, from conceptual design to operations. It is intended to help organisations implement the most effective safety controls first, minimising the likelihood of accidents and injuries.

This framework is widely used across industries where hazardous work conditions exist, including mining, oil and gas, construction, manufacturing, and power generation. It ensures that companies follow a logical order in managing risks, beginning with the most effective control measures and only using less effective methods when necessary.

The hierarchy consists of five levels, arranged from the most effective to the least effective:

1. Elimination – Completely removing the hazard
2. Substitution – Replacing the hazard with a safer alternative
3. Engineering Controls – Isolating people from the hazard using physical changes
4. Administrative Controls – Changing work policies and procedures to reduce risk
5. Personal Protective Equipment (PPE) – Using safety gear to minimise exposure to hazards

Each level plays a crucial role in reducing safety risk, but not all are equally effective. The goal is always to implement the highest level of control possible before relying on lower levels like administrative controls or PPE.

The Six Steps of the Hierarchy of Control Explained

The hierarchy of control is structured to address workplace hazards in a prioritised manner, ensuring that the most effective safety measures are applied first. Below, we examine each level in detail, along with examples of how they are used in high-risk industries.

3.1 Elimination (Most Effective)

Elimination is the highest and most effective level of control, as it removes the hazard entirely. By eliminating the source of danger, the risk is reduced to zero, making the workplace significantly safer.

Example:

• In a chemical processing plant, instead of handling hazardous substances manually, an automated system is installed to mix and dispense chemicals, eliminating direct worker exposure.
• In construction, redesigning a process so that workers never have to work at height removes the risk of falling completely.
• In a refinery, removing lead-based additives in fuel production by shifting to processes that don’t require any additive for octane boosting (e.g., relying on advanced refining techniques like catalytic reforming). This removes the lead hazard from the refinery altogether. Although elimination is the most effective control, it is not always feasible. In cases where the hazard cannot be removed entirely, the next best option is substitution.

3.2 Substitution

Substitution involves replacing a hazardous substance, material, or process with a less dangerous alternative. This method reduces the level of risk but does not eliminate it entirely.

Example:

• In painting operations, switching from solvent-based paints to water-based alternatives reduces exposure to harmful fumes.
• In manufacturing, replacing a toxic cleaning agent with a biodegradable, non-toxic version improves worker safety without compromising productivity.
• In the refinery example above, substituting lead based additives with unleaded alternatives.

Substitution must be carefully evaluated to ensure that the replacement does not introduce new hazards. If substitution is not viable, engineering controls should be implemented.

3.3 Engineering Controls

Engineering controls are physical modifications to the workplace, equipment, or processes that help isolate people from hazards. Unlike elimination and substitution, which remove or replace the hazard, engineering controls focus on designing solutions that reduce exposure.

Example:

• Installing machine guards to prevent workers from coming into contact with moving parts in a manufacturing plant.
• Using ventilation systems to remove toxic fumes from a confined workspace.
• Enclosing noisy machinery in soundproof barriers to protect workers from prolonged exposure to loud noise.

Engineering controls often require an initial investment but provide long-term safety improvements. If engineering solutions cannot sufficiently reduce the risk, administrative controls are considered.

3.4 Administrative Controls

Administrative controls involve changes to workplace policies, procedures, and training to reduce the likelihood of accidents. These measures rely on human behaviour and are generally considered less effective than physical controls.

Example:

• Implementing rotating shifts to minimise workers’ exposure to extreme heat or hazardous chemicals.
• Developing strict protocols for handling dangerous machinery, ensuring workers receive proper training before operation.
• Placing clear warning signs and labels in high-risk areas to alert workers of potential dangers.

While administrative controls help improve safety, they depend on employees following rules and procedures. This makes them less reliable compared to higher-level controls. If risks remain, the last line of defense is personal protective equipment (PPE).

3.5 Personal Protective Equipment (PPE) (Least Effective)

PPE includes safety gear such as gloves, helmets, goggles, earplugs, and respirators. It is the least effective control measure because it does not eliminate the hazard—rather, it minimises the potential for harm when exposure occurs.

Example:

• Workers in a chemical plant wearing respirators to prevent inhalation of hazardous fumes.
• Construction workers using safety harnesses when working at heights.
• Electricians wearing insulated gloves and protective clothing to reduce the risk of electrocution.

PPE should always be used as a last resort when higher-level controls are not sufficient. It also requires proper training, maintenance, and compliance to be effective.

The hierarchy of control provides a structured approach to workplace safety, ensuring that organisations prioritise safety risk reduction in the most effective way possible. In the next section, we will discuss how this framework is applied in risk management and permit-to-work processes.

The Role of the Hierarchy of Control in Risk Management

The hierarchy of control is a fundamental component of workplace risk management. By applying this structured approach, organisations can systematically assess and reduce hazards before they lead to incidents. This section explores how the hierarchy integrates with risk management strategies, regulatory compliance, and permit-to-work processes.

Integrating the Hierarchy of Control into Risk Assessments

Risk assessments are a critical step in identifying and controlling workplace hazards. The hierarchy of control provides a framework for evaluating risks and implementing the most effective control measures.

When conducting a risk assessment, safety managers typically follow these steps:

1. Identify hazards – Determine what could cause harm in the workplace.
2. Assess risks – Evaluate the likelihood and severity of potential incidents.
3. Apply control measures – Use the hierarchy of control framework to implement the most effective solutions.
4. Monitor and review – Regularly assess control measures to ensure they remain effective.

For example, if a manufacturing plant identifies high noise levels as a hazard, the risk assessment process might lead to implementing engineering controls such as soundproofing before considering PPE like earplugs.

Compliance with Safety Regulations

Many workplace safety regulations, including OSHA (Occupational Safety and Health Administration) and standards such as ISO 45001, emphasise the importance of a risk-based approach. These regulations require organisations to:

• Eliminate hazards where possible.
• Implement engineering and administrative controls before relying on PPE.
• Continuously assess and improve workplace safety practices.

Role in Permit-to-Work (PTW) Systems

A permit-to-work (PTW) system is a formalised safety process used for high-risk tasks such as confined space entry, hot work, and electrical maintenance. 

The permit to work is an administrative control, i.e. it is not possible to eliminate, substitute or engineer out the risk. The permit to work also helps manage the personal protective equipment layer of control. In addition the permit to work helps enforce safety procedures, for example by ensuring:

• Only competent and authorised personnel perform hazardous tasks.
• Risk assessments are completed before work begins.
• The highest level of control measures is implemented before work is authorised.
• Controls are continuously monitored throughout the task.

For example, before issuing a permit for welding operations in an enclosed space, safety managers might first eliminate the need for welding in that location (by removing the item to be welded to a workshop) or implement engineering controls like improved ventilation. By clearly understanding how the hierarchy of controls relates to  risk management and PTW systems, organisations can ensure safer operations and maintain compliance with industry standards. In the next section, we’ll explore some of the most common mistakes companies make when applying the hierarchy and how to avoid them.

Common Mistakes When Applying the Hierarchy of Control

While the hierarchy of control is a powerful framework for reducing workplace hazards, its effectiveness depends on how well it is applied. Many organisations unintentionally undermine their safety efforts by misusing or skipping critical steps in the hierarchy. Below are some of the most common mistakes and how to avoid them.

1. Skipping Higher-Level Controls

One of the biggest mistakes companies make is jumping straight to administrative controls or personal protective equipment (PPE) without first considering elimination, substitution, or engineering controls.

Example:

• A company dealing with excessive noise in a factory might issue earplugs (PPE) to workers instead of installing soundproofing (engineering control) to reduce the noise at the source.
• In a chemical plant, workers may be required to wear respirators, but a better solution could be replacing hazardous substances with less harmful alternatives.

How to avoid it:

• Always follow the hierarchy in order, implementing the highest level of control possible before relying on lower-level solutions.
• Conduct thorough risk assessments to explore whether elimination or substitution is viable before moving to administrative controls or PPE.

2. Relying Too Much on PPE

PPE is the least effective control measure because it does not remove or reduce the hazard—it only minimises the impact on workers. Relying on PPE as the primary safety measure is a common mistake.

Example:

• A maintenance team working at heights may be issued safety harnesses, but eliminating the need for working at heights altogether (elimination) or using a lift (engineering control) would be safer alternatives.

How to avoid it:

• Treat PPE as a last resort, not a primary control measure.
• Use PPE only when other controls are not feasible or as an additional layer of protection.

3. Not Reviewing Control Measures Over Time

Work environments, technologies, and hazards change over time, but some companies fail to reassess and improve their safety controls regularly.

Example:

• A factory installs ventilation systems (engineering control) to remove hazardous fumes but does not maintain them properly, reducing their effectiveness over time.

How to avoid it:

• Ensure that the hierarchy of controls framework is embedded in the design philosophy of the plant or facility.
• Implement a continuous review process to reassess risks and update control measures as needed.
• Ensure that adequate budget for capital expenditure is provided to eliminate, substitute or engineer out risks where applicable.
• Conduct regular safety audits and inspections to ensure existing controls remain effective.

4. Failing to Utilise Digital Tools to Manage Risk and Safety Controls

Many organisations still rely on manual or outdated processes, leading to inefficiencies and gaps in risk management. Without digital tools, it becomes difficult to track control measures, ensure compliance, and monitor workplace risks in real time. This applies equally to front end conceptual design (FEED) as well as to operations.

Example:

• A company uses a fragmented or spreadsheet-based permit-to-work process, increasing the likelihood of missing critical safety checks before high-risk tasks.
• Risk assessments are conducted infrequently, leading to outdated or inappropriate control measures.

How to avoid it:

• Incorporate risk management software in the front end engineering design of any plant, facility or major modification.
• Implement digital safety software like IntelliPERMIT to streamline risk assessments, permit approvals, and compliance tracking.
• Use real-time data analytics to monitor control measures and identify trends in workplace safety.

How IntelliPERMIT Enhances the Hierarchy of Control in Operations

While the lower layers of the hierarchy of control provide a structured approach to managing workplace safety, implementing these controls effectively requires real-time visibility, automation, and seamless coordination. This is where IntelliPERMIT plays a crucial role. By integrating digital safety solutions into workplace operations, IntelliPERMIT helps organisations systematically apply the administrative and PPE layers of the hierarchy of control framework while ensuring compliance and operational efficiency.

Ensuring Risk Assessments are Conducted Before Work Begins

Before any high-risk task is performed, a comprehensive safety risk assessment must be completed to determine the appropriate safety controls. IntelliPERMIT helps to automate this process by:

• Requiring risk assessments to be completed and reviewed before a work permit is issued and at the worksite before the job commences
• Ensuring only competent personnel can assess hazards and select appropriate control measures.
• Providing a centralised database of hazards and control measures, allowing safety managers to make informed decisions.

Integrating Competency-Based Access Control

One of the biggest risks in high-hazard environments is allowing inadequately trained or unauthorised workers to perform tasks they are not qualified for. IntelliPERMIT prevents this by:

• Restricting access to high-risk tasks based on worker competency, training, and certification levels.
• Automatically blocking permits for individuals who lack the necessary skills or safety training.
• Maintaining digital competency records to ensure workers meet safety requirements before receiving work authorisation.

Automating Compliance Checks

Ensuring that the correct hierarchy of control measures is in place before work begins can be challenging, especially in large industrial environments. IntelliPERMIT simplifies this by:

• Embedding pre-configured safety workflows that guide users through each step of the control hierarchy.
• Requiring digital sign-offs to confirm that hazard elimination, engineering controls, and administrative controls have been considered before relying on PPE.
• Providing automated alerts and notifications to supervisors if safety requirements are bypassed or ignored.

Reducing Administrative Burden and Streamlining Safety Approvals

Many organisations still rely on disconnected or manual permit-to-work processes, making it difficult to track safety controls and ensure compliance. IntelliPERMIT digitises the entire process by:

• Automating permit approvals with real-time tracking and validation.
• Centralising safety documentation, making it easy to retrieve audit logs and historical data.
• Enabling mobile access to safety checklists and risk assessments, allowing field workers to update permits in real time.

Providing Real-Time Insights into Safety Performance

Workplace safety is an ongoing process that requires continuous monitoring and improvement. IntelliPERMIT provides safety managers with real-time insights by:

• Generating data-driven reports on hazard control effectiveness.
• Tracking incident trends and near misses to identify areas for improvement.
• Offering custom dashboards that visualize compliance status across multiple work sites.

By leveraging IntelliPERMIT, organisations can fully implement the administrative and PPE layers of the hierarchy of control framework in a way that is systematic, data-driven, and fully auditable. This ensures that hazards are effectively managed and that the highest level of protection is always prioritised.

In the next and final section, we’ll summarise key takeaways and provide a call to action for organisations looking to enhance their safety systems.

Conclusion

The hierarchy of control is a vital framework for managing workplace hazards and ensuring the safety of employees in high-risk industries. By following its structured approach, organisations can systematically reduce risks, prioritise effective control measures, and create a safer work environment.

However, many companies struggle to apply the hierarchy correctly, often skipping key steps or relying too heavily on lower-level controls such as PPE. To truly maximise workplace safety, businesses must integrate the hierarchy of control into their full plant or facility lifecycles, ensuring that risk assessments, competency checks, and compliance measures are consistently enforced from conceptual design through to operations.

The bottom two layers of the framework (namely administrative and PPE controls) is is where IntelliPERMIT provides a powerful advantage. By digitising and automating operational safety processes, IntelliPERMIT ensures that:

• Risk assessments are completed and reviewed before work begins.
• Competency-based access control prevents unauthorised personnel from performing high-risk tasks.
• Compliance checks are enforced, ensuring that the best available safety controls are always prioritised.
• Safety approvals and reporting are streamlined, reducing administrative burdens and improving accountability.

As workplace safety continues to evolve, companies must leverage digital tools to strengthen their control measures, improve compliance, and reduce risks. Implementing IntelliPERMIT for administrative and PPE safety controls helps organisations to achieve a proactive, data-driven safety culture that minimises workplace hazards and prevents costly incidents.

For businesses looking to take their safety management to the next level, downloading the Practical Guide to Selecting Safety Software is a great first step. This guide provides insights into how digital tools can improve workplace safety, streamline operations, and ensure compliance with industry standards.Take action today—start applying the hierarchy of control effectively and systematically with the right safety technology.