From the Guidelines
The hierarchy of controls is a systematic approach to managing workplace hazards, ranked from most to least effective: elimination (physically removing the hazard), substitution (replacing the hazard with something less dangerous), engineering controls (isolating people from the hazard through physical changes), administrative controls (changing how people work through procedures and training), and personal protective equipment (PPE) as the last line of defense. This framework prioritizes hazard elimination at the source rather than relying on worker behavior. The hierarchy is effective because higher-level controls are more protective, reliable, and often more cost-effective long-term despite potentially higher initial investment. When implementing safety measures, organizations should start at the top of the hierarchy, working downward only when higher-level controls aren't feasible, often using multiple control types simultaneously for comprehensive protection. Some key points to consider when applying the hierarchy of controls include:
- Elimination and substitution are the most effective controls, as they remove or reduce the hazard at its source 1
- Engineering controls, such as ventilation systems or enclosure of processes, can be effective in reducing exposures to hazards 1
- Administrative controls, such as training and procedures, can help to reduce the risk of exposure to hazards, but are generally less effective than elimination, substitution, or engineering controls 1
- Personal protective equipment (PPE) should be used as a last line of defense, as it relies on worker behavior and can be less effective than other controls 1 The hierarchy of controls is a fundamental approach to occupational safety and health, and is applicable across a wide range of industries, including manufacturing, healthcare, and construction. By following the hierarchy of controls, organizations can reduce the risk of workplace hazards, protect worker health and safety, and minimize the economic and social impacts of work-related injuries and illnesses. For example, in the context of hazardous drugs, the hierarchy of controls might involve eliminating the use of hazardous drugs whenever possible, substituting them with less hazardous alternatives, using engineering controls such as biological safety cabinets, implementing administrative controls such as training and procedures, and providing PPE such as gloves and gowns 1. Similarly, in the context of COVID-19, the hierarchy of controls might involve eliminating the risk of exposure to the virus through measures such as remote work or social distancing, substituting high-risk activities with lower-risk alternatives, using engineering controls such as ventilation systems, implementing administrative controls such as screening and testing, and providing PPE such as masks and respirators 1. Overall, the hierarchy of controls is a powerful tool for managing workplace hazards and protecting worker health and safety, and should be applied consistently and systematically across all industries and occupations.
From the Research
Hierarchy of Controls
The hierarchy of controls is a framework used to minimize or eliminate hazards in the workplace. It is a step-by-step approach to controlling hazards, with the most effective controls at the top of the hierarchy and the least effective at the bottom.
- Elimination: The most effective control is to eliminate the hazard altogether. This can be done by removing the hazardous substance or process from the workplace.
- Substitution: If elimination is not possible, the next step is to substitute the hazardous substance or process with a safer one.
- Engineering controls: Engineering controls involve modifying the workplace or equipment to reduce the risk of exposure to the hazard. Examples include ventilation systems, machine guards, and personal protective equipment.
- Administrative controls: Administrative controls involve changing the way work is done to reduce the risk of exposure to the hazard. Examples include rotating jobs, scheduling work during less busy times, and providing training and procedures.
- Personal protective equipment (PPE): PPE is the least effective control and should only be used when other controls are not possible. Examples include respirators, gloves, and safety glasses.
Unfortunately, there are no research papers provided to assist in answering this question about the hierarchy of controls 2, 3, 4, 5.