Hierarchy of Controls

Understanding the Hierarchy of Controls: Why PPE is the Last Resort

by Seo Coder on October 10, 2023

When it comes to ensuring safety in the workplace and minimizing risks, a well-established principle known as the Hierarchy of Controls serves as a guiding framework. This hierarchy outlines a systematic approach to risk management, with the ultimate goal of eliminating or reducing hazards to the lowest practicable level. In this blog, we'll delve into the Hierarchy of Controls and explore why Personal Protective Equipment (PPE) is considered the last resort in the quest for safety.


The Hierarchy of Controls Explained

The Hierarchy of Controls is a concept widely recognized and endorsed by safety professionals and organizations worldwide. It consists of five levels, listed in order of preference and effectiveness:

1. Elimination

At the top of the hierarchy is elimination, which aims to completely remove the hazard from the workplace. This is often the most effective way to control risks as it eradicates the danger altogether. However, elimination is not always feasible, especially when the hazard is inherent to the process or activity.

2. Substitution

Substitution involves replacing the hazardous substance, process, or equipment with something less harmful. While it doesn't eliminate the hazard, it reduces the risk significantly. Substitution may include using less toxic chemicals, safer machinery, or alternative processes.

3. Engineering Controls

Engineering controls focus on designing physical or mechanical modifications to isolate people from the hazard. Examples include machine guarding, ventilation systems, and noise barriers. These controls are highly effective and do not rely on individual behavior.

4. Administrative Controls

Administrative controls involve changes to work practices, policies, and procedures to reduce risk. This level includes scheduling, training, signage, and job rotation. While important, administrative controls depend on human compliance and may not eliminate hazards entirely.

5. Personal Protective Equipment (PPE)

PPE is the final level of defense in the Hierarchy of Controls. It includes safety gear like helmets, gloves, respirators, and safety glasses. PPE is worn by individuals to protect themselves from residual risks that cannot be eliminated or adequately reduced by the other control measures.


Why PPE is the Last Resort

Now that we understand the hierarchy let's explore why PPE is considered the last resort in controlling workplace hazards.

1. Limitations of PPE

PPE has certain inherent limitations:

Reliance on Human Behavior: PPE depends on individuals consistently wearing and using it correctly. Human error or non-compliance can compromise its effectiveness.

Inability to Eliminate Hazards: PPE does not eliminate the hazard itself but mitigates exposure. Therefore, it does not address the root cause of the risk.

Maintenance and Fit: PPE requires regular maintenance and proper fit to be effective. Damaged or ill-fitting gear can fail to provide adequate protection.

2. Cost Considerations

Implementing engineering controls or substituting hazardous materials or processes may require an initial investment. However, over the long term, these measures often prove more cost-effective than continually purchasing and replacing PPE.

3. Emphasis on Prevention

The primary goal of the Hierarchy of Controls is hazard prevention. By prioritizing elimination, substitution, and engineering controls, organizations aim to create inherently safer workplaces. This approach aligns with the philosophy that it's better to prevent accidents from happening in the first place rather than relying on PPE to minimize harm after a hazard occurs.

4. PPE as a Complementary Measure

PPE is not to be dismissed; it is an essential safeguard when other controls are insufficient. In many cases, PPE complements higher-level controls. For instance, workers may wear earplugs (PPE) in addition to working in a quieter area (engineering control) to protect against hearing damage.


When PPE is Appropriate

While PPE is the last resort, there are situations where it remains a crucial component of safety measures:

1. Temporary Hazards

PPE is particularly valuable when workers encounter sporadic or temporary hazards that cannot be eliminated through permanent changes, such as maintenance activities or handling hazardous materials.

2. Supplementing Higher Controls

PPE can enhance safety when used alongside other control measures. For example, wearing a dust mask while working with a dust extractor (engineering control) adds an extra layer of protection.

3. Emergency Situations

In emergencies like fires or chemical spills, PPE can provide immediate protection until other control measures can be implemented.



In conclusion, the Hierarchy of Controls is a systematic approach to managing workplace hazards, prioritizing elimination, substitution, and engineering controls before relying on Personal Protective Equipment (PPE). PPE is not to be underestimated; it plays a crucial role in safeguarding workers when other control measures fall short or when temporary hazards arise. However, understanding why PPE is the last resort underscores the importance of preventing hazards at their source whenever possible, ultimately promoting a safer and healthier work environment for all.