Hierarchy of Hazard Controls: The 5 Safety Controls Explained

Hierarchy of Hazard Controls

What Is the Hierarchy of Controls?

The safety hierarchy of controls is a hazard control measure model that removes the hazard or minimizes the risk. Essentially, it's an ordered list of control categories that you can use to identify and rank potential safeguards.

It's also called the hierarchy of hazard controls or the risk control hierarchy.

This hierarchy of controls is widely accepted by safety and health professionals. It's endorsed by the Occupational Safety and Health Administration (OSHA), National Institute for Occupational Safety and Health (NIOSH), and the National Safety Council (NSC).

What Is the Most Effective on The Hierarchy Of Controls?

According to NIOSH's hierarchy of controls, there are five categories: elimination, substitution, engineering controls, administrative controls, and personal protective equipment (PPE). Some models consider elimination and substitution as a single tier to make a four-level hierarchy.

Either way, these controls are listed according to their effectiveness, with elimination and substitution topping the list. After all, the safest way to deal with a hazard is to eliminate it.

Hierarchy of Controls Examples and Explanations

When using the hierarchy controls, OSHA notes that each safety control you consider must be "feasible." Feasible controls are suitable for the hazard, appropriate to the risk level, consistent with regulations, not too burdensome to workers, effective and reliable, readily available, and cost-effective in the short and long term.

The idea is to start looking for hazard controls in the first category, then move on to the next one if a solution isn't feasible or sufficient to control the hazard. It's not unusual for a workplace to need two or three solutions to reduce the risk of one hazard adequately.

Safety Control Categories #1 and #2: Elimination and Substitution

The most effective type of hazard control is the elimination, as we mentioned above. The second-most effective is substitution.

There's a fine line between the two categories, so they're sometimes grouped. After all, if you replace a toxic chemical with one that's 100% safe, which type does that control fall into?

In other cases, the difference is more distinct. For example, you might eliminate the use of sharp cutting tools by purchasing materials that come in the necessary size, with no substitution involved. Alternatively, you might substitute one hazardous chemical for a less toxic one, which isn't elimination, just mitigation.

Elimination and substitution are far more effective than any other options in the risk control hierarchy, but they can be a hard sell for existing work environments. It's easiest to consider elimination or substitution during the design process.

Safety Control Category #3: Engineering Controls

Employers should consider engineering controls when elimination and substitution are impossible or insufficient.

Engineering controls protect workers by separating them from the hazard. This is typically done with machines, equipment, barriers, or workspace design, which must be engineered. The most effective engineering controls are part of the original design, not a retrofit, but modification also counts.

While engineering controls usually require more upfront investment, it often costs less in the long term, especially compared to administrative controls or PPE for multiple workers.

They're also more effective in preventing injury and illness when used correctly. Employees don't need to remember and enact a new procedure or put on PPE if they're kept away from the hazard altogether.

Examples of engineering controls include machine guarding, remote machine operation, exhaust ventilation systems, and guardrails.

Safety Control Category #4: Administrative Controls

Administrative controls are procedures, processes, and warning systems for increased safety. To be effective, they must be followed or heeded (and done so every time), which is why they're considered a backup to engineering controls.

Examples of administrative controls include operating procedures, equipment inspections, limits on exposure time, alarms, warning signs, labels, the buddy system, checklists, and lockout/tagout.

Lockout/Tagout Safety in the Workplace


Safety Control Category #5: Personal Protective Equipment

PPE should be the last resort for reducing or eliminating risk to a worker – meaning all feasible controls in the other categories are being implemented but can't stop the threat.

PPE may be the first thing people picture when they think about workplace safety, so why is it last on the list? Personal protective equipment needs constant attention to be effective. Workers must use them correctly, and they're often uncomfortable or cumbersome. They have to be fitted perfectly and maintained correctly. For all these reasons, PPE is hardly a failsafe – but sometimes, it's the best you can do.

Examples include hard hats, safety glasses, hearing protection, respirators, protective clothing, and equipment attached to the person, like personal fall protection systems.

SST 4-Hour Fall Prevention


SST 8-Hour Fall Prevention


Where Does Training Fit in the Risk Control Hierarchy?

Ultimately, workplace safety training aims to teach people the safest way to work, making them a type of administrative control. However, that doesn't make it a last resort. It's crucial that your workforce is educated in the importance of workplace safety and hazard recognition in general, not just specific safe work practices.

Working with an online OSHA-authorized training provider like us can be a perfect match if you struggle to provide consistent, organized, cost-effective safety training. The courses are self-paced, expertly designed, and available at everyone's convenience. Our free learning management system makes assigning classes easy and keeps track of everyone's completion certificates.

Check out our extensive safety training catalog and contact us today!