National Safety Month Week Three: Risk Reduction through the Hierarchy of Controls
Welcome to Week 3 of National Safety Month! The focus this week is on Risk Reduction and today we will discuss how to use the Hierarchy of Controls to guide your risk reduction process.
What is the Hierarchy of Controls?
According to OSHA The hierarchy of controls is “a method of identifying and ranking safeguards to protect workers from hazards.” The hierarchy is typically illustrated as an inverted triangle with the most effective safeguard method at the top and least effective method at the bottom. The methods are identified as follows in order from most effective to least effective.
Elimination - eliminate the hazard by physically removing it
Substitution - replace the hazard with something less hazardous
Engineering Controls - isolate people from the hazard
Administrative Controls - change the way people work
Personal Protective Equipment (PPE) - wear protective clothing
A Deeper Dive
The level of risk of injury or illness due to exposure to a hazard varies according to likelihood of exposure, duration or frequency of exposure, and severity of consequences following exposure. Multiple layers of control may be required to effectively control a hazard if it cannot be eliminated entirely.
Elimination: an example of hazard elimination could include stopping use of a hazardous chemical or tool. This removes the source of the hazard entirely from the workplace.
Substitution: An example of substitution could include replacing a highly hazardous chemical with one that is less hazardous. For example, swapping out a highly toxic solvent such a carbon tetrachloride with a less toxic solvent such as cyclohexane. This substitution can reduce the level of risk, however residual risks associated with the replacement material still need to be addressed (e.g., flammability)
Engineering Controls: An example of an engineering control includes machine guarding. Guarding effectively separates the worker from the hazard of the point of operation.
Administrative Controls: Examples of administrative controls includes scheduling, work rotation, training, establishing procedures and rules, inspections and checklists. These controls are highly dependent upon individual behavior. An administrative control frequently applied to occupational heat exposure is to schedule work during cooler times of the day and reducing employee exposure by managing work-rest cycles.
Personal Protective Equipment (PPE): PPE including safety glasses, hard hats, gloves, face shields and safety footwear provides a barrier between the worker and the hazard, however it is not 100% reliable and exposure can still occur. When managing respiratory hazards, respirators are the last line of defense and are only used as an additional safeguard if elimination is not possible and other controls are not sufficient to reduce the hazard to a safe level. Personal fall arrest harnesses and lanyards are forms or PPE. The employee is still exposed to a fall, however the used of the harness and lanyard reduces the severity of the injury due to the fall.
Key Takeaway:
When selecting a method to protect your employees and reduce the risk of injury or illness from workplace hazards, follow the hierarchy of controls. Wherever possible, eliminate the hazard. If the hazard cannot be eliminated, apply substitution, engineering controls, administrative controls and PPE. Often multiple methods at varying levels of the hierarchy of controls may be needed to effectively reduce