If you run in Occupational Health and Safety circles, chances are you've heard about the Hierarchy of Hazard Controls. It's a term that's often associated with safety management systems that are structured around workplace hazard management, and it might sound a bit intimidating but, really, all it is is a ranking of the methods used to control hazards.

But what exactly is the ranking and how is it used? To answer that question, we'll go over the list and each of the items in it.

What Is the Hierarchy of Hazard Controls?

The Hierarchy of Hazard Control seeks to protect workers by ranking the ways in which hazards can be controlled, providing employers with a framework for reducing risk to employees.

The Hierarchy contains six items:
  1. Elimination
  2. Substitution
  3. Isolation
  4. Engineering controls
  5. Administrative controls
  6. Personal protective equipment

The idea behind the ranking is that the control methods at the top of the list are more effective and protective than those at the bottom.

1. Eliminate the Hazard

The best way to control a hazard is to eliminate it. This can be achieved by making changes to the work process so that the task is no longer carried out, or by physically removing the hazard altogether.


Elimination is the most effective way to control hazards and should be used whenever possible. However, it can also be the most difficult to implement, especially if the process is still at the design or development stage. For example, dangerous machinery is often a necessary component of certain work processes, and while it can be made safer, it can't be eliminated.

2. Substitute One Risk for a Lesser One

Substitution is the second most effective method for controlling hazards. It is similar to elimination but rather than removing the risk altogether, it involves substituting one risk for another.


Say, for example, that your employees work with a highly hazardous solvent and that you discover a less dangerous one that will still do the job. By swapping the chemicals, you won't be eliminating the risk entirely, but you will be reducing it.

3. Isolate the Hazard From the Person at Risk

Isolation involves separating the hazard in time or space from the person or persons at risk. This can be achieved by isolating the hazard through containment or enclosure. These methods aim to, basically, keep the hazard "in" and the worker "out" (or vice versa). One example of isolation would be building a sound-reducing enclosure around a piece of equipment to protect workers from hearing damage (learn more about The Effects of Noise on the Body).

4. Use Engineering Controls

If a hazard can't be eliminated, isolated, or substituted, the next best approach is to use engineering controls. Engineering controls are implemented by making changes to the design of an equipment or process to minimize its hazard. Although engineering controls are the most expensive solution, they provide the advantage of reducing future cost.


The two basic types of engineering controls are process control and ventilation. Process control involves changing the way a job activity or process is performed to reduce hazards, such as the use of electric motors rather than diesel motors to eliminate diesel exhaust emissions. Ventilation is a method of control that strategically adds and removes air in the work environment, such as the use of local exhaust fans to control titanium dioxide dust in a paint manufacturing factory.

5.Use Administrative Controls

If engineering controls cannot be implemented, move on to considering administrative controls. These, however, don't actually remove or reduce the hazards, so they are less effective in comparison to other control measures in the hierarchy.


Administrative controls involve making changes to the way in which people work and promoting safe work practices through education and training. Administrative controls may involve training employees in operating procedures, good housekeeping practices, emergency response in the event of incidents such as fire or employee injury, and personal hygiene practices such as the washing of hands after contact with hazardous materials.

6.Use Personal Protection

This is the least effective method of controlling hazards because of the high potential that personal protective equipment (PPE) will become damaged. If PPE is inadequate or fails, the worker is not protected. It can also often be uncomfortable, which can place an additional physical burden on the worker. Therefore, PPE should only be used in combination with other control measures from the hierarchy or if there are no other more effective ways to control the hazard (learn more about PPE and how to use it in 6 Personal Protective Equipment Guidelines Every Employee Should Know).


The Role of Management

It is the responsibility of management to design jobs safely or redesign them when a hazard is detected. Management should, therefore, gain a sufficient understanding of the Hierarchy of Hazard Control to ensure that the most appropriate control measure is selected and is working effectively in reducing or eliminating hazards and preventing injuries or accidents in the workplace. However, selecting an appropriate control measure is not always easy. It often involves conducting a risk assessment to evaluate and prioritize the hazards and their risks.

The Role of Employees

It is the role of employees to promote the use of the Hierarchy of Hazard Control to ensure that management is providing the most effective methods of hazard control. Employees should also maintain an open line of communication with management so they can inform them of potential hazards and suggest ways of controlling them (for more on the importance of communication between employees and management, see Implementing a Safety Culture: Speak Up for Safety).

Why Follow the Hierarchy?

Having a safety program in place is a necessity, but it pays to make sure that it's also a strategic one. The Hierarchy of Hazard Control gives employers and safety professionals a tool to effectively tackle their workplace hazards. Prioritizing control methods doesn't just make for a safer workplace; it also reduces costs and minimizes waste.

So the next time you need to deal with a hazard, start by asking yourself "Can we do anything to eliminate the hazard?" and, if not, start working your way down the list.