What is the hierarchy of controls in the workplace?

The hierarchy of controls is a systematic, step-by-step approach aimed at eliminating or reducing hazards in the workplace. This hierarchy ranks control methods from most effective to least effective, and you should always start with the options highest in the hierarchy before moving to lower levels if the most effective methods are not possible or sufficient [4].

Levels of the Hierarchy of Controls

The hierarchy of controls consists of five main levels:

• Elimination: This is the most effective method, involving the complete removal of the hazard from the work environment. For example, purchasing equipment that does not generate noise, or removing stored products that are no longer used correctly [4].
• Substitution: If it is not possible to eliminate the hazard, the next step is to replace it with a less hazardous material or process. Examples include replacing solvent-based paints with water-based alternatives, or using a coarser granular form of a product instead of fine powder to reduce dust generation [4].
• Engineering Controls: These controls aim to isolate workers from the hazard or reduce exposure through modifications to the work environment or equipment. Examples include installing local exhaust ventilation systems to remove contaminants at the source, using physical barriers, or using mechanical lifting devices instead of manual lifting [4].
• Administrative Controls: These involve developing procedures to ensure work is performed in a way that minimizes hazards. These controls do not eliminate the hazard itself but limit worker exposure to it. Examples include task rotation schedules to reduce exposure periods, implementing preventive maintenance programs for equipment, restricting access to hazardous work areas, or using warning signs [4].
• Personal Protective Equipment (PPE): This is the final and least effective level, and it should be used when other levels are insufficient or impossible. PPE includes anything workers wear to protect them from hazards, such as respiratory protection, gloves, eye protection, and hearing protection. This equipment must be appropriate for the hazard, and workers must be trained in its proper use and maintenance [4].

Why is the hierarchy important?

Applying the hierarchy of controls helps create a safer and healthier work environment by prioritizing solutions that provide the highest level of protection. By focusing on eliminating or controlling the hazard at the source, organizations can reduce reliance on less reliable measures, such as PPE, which may fail or not be used correctly [4]. This approach reduces work accidents, injuries, and occupational diseases, benefiting both worker health and company productivity [2].

Practical considerations for applying the hierarchy

To make the most of the hierarchy of controls, employers should:

• Assess risks comprehensively: Identify all potential hazards in the work environment and assess their severity before selecting control methods [1].
• Combine control methods: Often, controlling a hazard may not be possible using only one method, and it may require combining several levels of the hierarchy to ensure adequate protection [4].
• Training and awareness: Workers must be adequately trained on the hazards present in their workplace and how to apply the various controls, including the correct use of PPE [3].
• Review and evaluation: The effectiveness of implemented controls must be reviewed regularly and updated as needed, especially when introducing new processes or equipment, or when changes occur in the work environment [4].

For more information on occupational health and worker safety, you can visit Occupational Health and Worker Safety: Preventing Injuries and Illnesses in the Workplace (Arabic).

Medical references

• CCOHS: Hazard and Risk - Hierarchy of Controls
• NIOSH A-Z Index
• Occupational Health
• Young Worker Safety and Health