Toolbox Topic: Hierarchy of Controls
When it comes to safety, you’ll want to make sure that you’re implementing the right controls in the right order. The hierarchy of controls is a method for best-controlling exposure to workplace hazards. There are five levels to the hierarchy of controls, and in today’s episode, we will discuss each of them.
Definition of Hierarchy of Controls
The hierarchy of controls has five levels of actions to reduce or remove hazards. These are in the preferred order based on effectiveness:
- Elimination
- Substitution
- Engineering controls
- Administrative controls
- Personal protective equipment (PPE)
Hierarchy of Controls
# 1 Elimination
Elimination is always the preferred solution. Elimination removes the hazard at the source. This could include eliminating the use of a toxic chemical, the need to lift a heavy object or the use of a sharp tool.
I can give you a real-world example. I worked with a warehousing company, and some products came from the manufacturer in wooden crates that were nailed together—opening the containers exposed employees to cuts and lacerations. We contacted the manufacturer and they agreed to use screws instead of nails. The product could be safely removed using a cordless drill, thus eliminating the hazard.
#2 Substitution
Although eliminating the hazard at the source is the most effective way to prevent accidents, it can’t always be done. Substitution can work when a safer alternative can be implemented—for example, instead of using solvent-based inks a printer may be able to substitute plant-based inks instead. Remember for substitutes to be effective they must reduce the potential for harmful effects but at the same time they cannot create any new hazards. When considering a substitute, it’s essential to compare the potential new risks of the alternative to the original hazards.
#3 Engineering Controls
Engineering controls reduce or prevent hazards from coming into contact with workers. Engineering controls can include modifying equipment or the workspace and using protective barriers, i.e., guards, ventilation, etc.
The most effective engineering controls:
are part of the original equipment design
remove or block the hazard at the source before it can come into contact with the worker
prevent users from modifying or interfering with the control
need minimal user input for the controls to work
operate correctly without interfering with the work process or making the work process more difficult
Engineering controls can cost more upfront; however, long-term operating costs tend to be lower, especially when protecting multiple workers. In addition, engineering controls can save money in other areas of the work process or facility operation.
#4 Administrative Controls
Administrative controls establish work practices that reduce exposure to hazards’ duration, frequency, or intensity. This may include:
work process training
job rotation
ensuring adequate rest breaks
limiting access to hazardous areas or machinery
adjusting line speeds
#5 PPE
Personal protective equipment is worn to minimize exposure to hazards. Examples of PPE include gloves, safety glasses, hearing protection, hard hats, and respirators. Elements of the PPE program depend on the work process, the program should include the following:
Workplace hazards assessment
PPE selection and use
Inspection and replacement of damaged or worn-out PPE
Employee training
Program monitoring for continued effectiveness
PPE should always be the last line of defense! PPE can be effective only when workers use it correctly and consistently. When other control methods cannot reduce hazardous exposure to safe levels, PPE must be made available and its use enforced. This can include:
While other controls are under development
When other controls cannot sufficiently reduce the hazardous exposure
When PPE is the only control option available
Administrative controls and PPE require significant and ongoing effort by workers and their supervisors and that is why they come last in the hierarchy of controls.