All workplaces inherently harbor various hazards. In order to establish a safe working environment and ensure the well-being of employees, it becomes imperative to identify and manage the risks that may stem from these hazards. One effective method for adeptly managing occupational hazards like accidents, injuries, and illnesses is through the application of the hierarchy of risk control. The risk control hierarchy serves as a framework for selecting the most efficient control measures that can be employed to either eradicate or diminish the risks identified during the risk assessment process. It provides a universally accepted and steadfast approach to overseeing workplace safety and preventing workplace injury. The risk control hierarchy comprises five distinct stages.
Within this article, we shall delineate the hierarchy of controls and delve into the five stages of safety control measures that can be implemented to safeguard employees, mitigate hazards, or entirely eliminate them.
What is the Hierarchy of Risk Control?
The Hierarchy of Risk Control, a widely accepted and structured method approved by global safety organizations such as NIOSH, OSHA and NSC, is used to ensure workplace safety. It consists of 5 levels of control measures such as elimination of hazards, substitution, engineering controls etc.
The hierarchy prioritizes controls according to their effectiveness in reducing or eliminating risks. It starts with the highest level of protection, which involves the elimination of the hazard, and progresses to lower levels involving substitution, engineering controls, administrative controls and finally the use of personal protective equipment (PPE). The aim is to systematically select and implement the most effective control measures to minimize workplace hazards and protect workers from potential harm.
History of Hierarchy of Controls
Before the 1940s, workplace safety was generally evolving through trial and error. For example, during that time, an experimental method known as “fly-fix-fly” was applied in the design and testing phases of experimental aircraft. In this method, after a flight, faults were identified, addressed, and then the aircraft was flown again. This experimental method resulted in many injury accidents and fatalities. A more effective system was clearly required.
The implementation of a safety framework named the “hierarchy of risk controls” began in 1950 under the NSC’s initiative. The primary objective of this framework was to manage and mitigate exposure to potential hazards and risks as a means of safeguarding employees. The origin of the hierarchy concept can be traced back to the establishment of OSHA through the Occupational Safety and Health Act (OSH Act) of 1970 and the inception of the National Institute for Occupational Safety and Health (NIOSH). In 2017, NIOSH took the lead in launching a nationwide campaign known as “Prevention through Design” (PtD).
Why is it Important?
The hierarchy of risk control is particularly important when it comes to protecting workers in environments where they may encounter hazards. It is especially crucial in workplaces where workers are constantly exposed to dangers such as toxic chemicals, air pollutants, diseases and illnesses, vehicle-related accidents, and machinery accidents.
The hierarchy of risk control plays a significant role in preventing or reducing occupational injuries and illnesses, and it is an essential component of the Prevention through Design (PtD) method. PtD utilizes the hierarchy of risk control in the following ways:
- Removing dangers and risks right from the beginning or in the initial phases of their life cycles.
- Crafting, reshaping, or reinforcing work environments, equipment, and protocols for the safeguarding of workers.
- Integrating preventative approaches into the workflow design.
Why Use the Hierarchy of Risk Control?
Since its inception in the 1950s, the hierarchy of risk controls has been at the core of workplace safety laws and regulations. Playing a crucial role in safeguarding workers from workplace hazards and injuries, the hierarchy of risk controls has been integrated as a strategy into national PtD initiatives.
OSHA emphasizes the implementation of this hierarchy for safety and health programs.
NFPA recommends incorporating the hierarchy of controls into risk assessment processes aimed at preventing injuries and fatalities resulting from shock, electrical hazards, and arc flashes.
NSC uses these risk controls, which places an emphasis on safety, as a helpful reference in workshop practices and safety applications.
It is undeniable that this hierarchy is closely related to workplace safety. Through this hierarchy, employers can both protect their employees and effectively manage existing risks. The hierarchy of risk controls also serves as a template for understanding how hazards and risks can be minimized to prevent injuries and fatalities.
5 Stages of Hierarchy of Risk Control
The stages in the hierarchy are arranged based on their effectiveness levels, depicted in a triangular graph from the most effective stage to the least effective one. Each of the five stages can be thought of as defense mechanisms that prevent workers from being exposed to or affected by occupational hazards.
1. Elimination
Elimination is the process of completely removing or physically distancing a hazard from the workplace, representing the most effective stage of the hierarchy of controls. When hazards are eliminated or removed from a work environment, they can no longer adversely affect workers. While it is considered the most effective stage, it is also the most challenging to implement. It can be highly costly and may require significant changes to existing processes.
Examples:
- Eliminating trip hazards on the floor.
- Performing tasks at ground level instead of working at heights.
- Removing chemicals from the work environment that can cause severe skin irritations.
2. Substitution
Substitution, the second most effective stage of safety control, involves replacing a hazardous substance or activity with safer alternatives. It is similar to the elimination stage in that it either eliminates the hazard in the workplace or minimizes its adverse effects on injuries or employee health.
Examples:
- Use mild detergent and hot water instead of caustic cleaners for cleaning.
- Substituting solvent-based paint with water-based paint.
3. Engineering controls
Engineering controls involve modifying equipment, processes, or the work environment to reduce risks, physically separate or isolate workers from hazards. Many businesses use engineering controls to eliminate hazards before workers are exposed, rather than after. While implementing engineering controls may be costly, they reduce overall operating costs due to the safety features they provide.
Examples:
- Placing barriers around noisy machinery.
- Restricting access to high-voltage equipment.
- Using remote controls to operate machines.
4. Administrative controls
Administrative controls are any training, practice, or design change that reduces the likelihood of an employee’s exposure to hazards. Administrative controls, which provide a lower level of protection, are typically used in conjunction with other processes that do not completely eliminate hazards.
Because they are more cost-effective, businesses often prefer this stage, which requires significant effort from employees.
Examples:
- Limiting the time employees are exposed to hazards.
- Creating safe use manuals for machinery and tools.
- Placing signs, labels, and warnings.
5. PPE
PPE refers to the physical gear that employees use or wear to mitigate health and safety risks. It represents the lowest and least effective level of protection in the hierarchy of controls.
Utilizing PPE as a safety control can be costly in the long run and may be ineffective if not worn or used correctly.
Examples:
- Eye and face protection (goggles and masks).
- Head protection (helmets).
- Hand and arm protection (chemical-resistant or flame-resistant gloves).
