A safe work environment is fundamental to the success of any operation. When hazards are present, the most effective solutions are often built directly into the workplace. These physical solutions, known as engineering controls, are designed to mitigate risks at their source by separating people from potential harm.
Defining Engineering Controls
Engineering controls are physical changes made to the workplace, equipment, or a process to reduce or eliminate exposure to hazards. The core principle is the modification of the work environment itself to protect employees. These controls are engineered to be a permanent part of the workplace, functioning as a barrier between the worker and the hazardous condition.
An effective engineering control operates without requiring specific actions from an employee. For instance, a guardrail on an elevated platform provides protection regardless of a worker’s behavior, and a laboratory fume hood automatically removes airborne contaminants. This approach is proactive, aiming to prevent incidents by addressing the root cause of the risk within the physical environment.
By building safety directly into the design of a workspace or machine, companies can significantly reduce the likelihood of accidents. The primary goal is to create a situation where the safe way of performing a task is the easiest and most logical path.
The Hierarchy of Controls
Safety professionals use a framework called the Hierarchy of Controls, which is promoted by organizations like the Occupational Safety and Health Administration (OSHA). This model ranks different types of hazard controls into five levels, ordered from most to least effective. Understanding this hierarchy helps clarify the strategic role of engineering controls.
The most effective level is Elimination, which involves physically removing the hazard entirely. The next level is Substitution, which means replacing a hazardous material or process with a safer alternative. These two levels are considered the most protective because they remove or significantly reduce the hazard itself.
Engineering Controls are the third level and are highly preferred because they isolate people from the hazard. Below this are Administrative Controls, which change the way people work through procedures or training. The final and least effective level is Personal Protective Equipment (PPE), which requires workers to wear gear like gloves or respirators. Engineering controls are more effective than the lower levels because they provide consistent protection that is not dependent on human action.
Common Examples of Engineering Controls
Practical applications across different industries show how physical changes can mitigate specific workplace hazards.
- Ventilation systems are used to manage airborne contaminants. Local exhaust ventilation captures hazardous fumes, dust, and vapors at their source, while general dilution ventilation exchanges the air in an entire room to reduce the concentration of contaminants.
- Isolation and enclosures physically separate workers from a hazardous process or material. This can be achieved with enclosures like glove boxes or by placing noisy machinery inside soundproof rooms to protect workers from hearing damage.
- Machine guarding prevents injuries from moving machinery parts. Physical barriers like shields prevent contact with dangerous components, while advanced systems like light curtains automatically shut down a machine when a person enters a hazardous area.
- Ergonomic controls are designed to reduce physical stress and prevent musculoskeletal injuries. Examples include adjustable workstations, lifting assistance devices like hoists, and anti-fatigue mats for those who stand for long periods.
Benefits and Limitations
Implementing engineering controls offers significant advantages for workplace safety. Their primary benefit is high reliability, which can lead to long-term cost savings by reducing expenses associated with injuries and the ongoing need to purchase and maintain PPE. A safer work environment can also lead to improved productivity and employee morale.
However, there are also limitations. The initial capital cost of designing and installing engineering controls can be substantial. Implementation can also cause temporary disruptions to operations during the installation or retrofitting process. In some situations, it may not be feasible to implement an engineering control due to the nature of the task or constraints of the physical environment.